TIGHAR
Amelia Earhart Search Forum => Radio Reflections => Topic started by: Ric Gillespie on September 23, 2011, 11:24:38 AM
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At long last our Catalog and Analysis of Post-Loss Radio Signals During the Search for Amelia Earhart in June 1937 (http://tighar.org/Projects/Earhart/Archives/Research/ResearchPapers/Brandenburg/signalcatalog.html) is ready for prime time. The amount of work that has gone into collecting, compiling, cataloging and analyzing these signals boggles the mind. Over the past twenty years, dozens of TIGHAR researchers have contributed to this important aspect of our investigation of the Earhart disappearance but we want to especially thank LCDR Robert Brandenberg, USN (ret) whose tireless dedication and extraordinary expertise have made this catalog possible.
Radio signals, although invisible and fleeting, are just as real as bones and artifacts. This is the first comprehensive compilation of what signals were reported and which of them are credible. The importance of the story they tell is difficult to overstate. This catalog is an essential tool in piecing together that story. Take a look.
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Ric,
Re the post loss signal catalog.
Have you and Bob B. discussed how it may have been possible for AE to pick up the KGMB broadcast, and apparently responded, but being unable to hear the Itasca at any point in the flight.
What radio would AE have used to hear KGMB?
Ted Campbell
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What radio would AE have used to hear KGMB?
Her Western Electric 20B receiver - the only receiver she had on the airplane. We know the receiver was working because she heard the Morse code "A"s that Itasca sent on 7500 Khz. She heard that signal over her loop antenna, so we know the loop was working. She didn;t hear anything else from Itasca because she switched back to the (missing) belly antenna. To hear KGMB, all she had to do was realize that her belly antenna was gone and use the loop. Once she was on the ground she could get out of the airplane and see that the belly antenna was gone.
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Ric,
So what you are sugesting is that AE's loop antenna was capable of receiving voice signals, this assumes that the KGMB was by voice, yet she didn't receive/reply to Itasca's voice transmissons. Strange!
The question then becomes was the Itasca's radios operating correctly?
Ted Campbell
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Ted,
I think the source of your confusion is Earhart was listening for the Itasca's transmissions on the belly antenna. If it were missing or damaged in some way, this would explain why she apparently never heard any of the ship's voice transmissions. She only heard the ship upon switching to the loop antenna while trying to take a bearing. She then switched back to the belly antenna to for voice reception and apparently continued to be frustrated by not hearing anything.
If she truly did hear the KGMB broadcast, either she managed to repair the belly antenna or realized it was gone and relied on the loop antenna for receiving voice whereas she had not done so during flight.
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Ric,
Re the post loss signal catalog.
Have you and Bob B. discussed how it may have been possible for AE to pick up the KGMB broadcast, and apparently responded, but being unable to hear the Itasca at any point in the flight.
What radio would AE have used to hear KGMB?
Ted Campbell
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Did Brandenburg do an analysis of the probability of Earhart on Gardner being able to hear the 1 kw signal from KGMB at the times that she would have needed to hear it in order to reply to it. He did such an analysis of its probability of being heard on the mainland to eliminate the possibility of hoaxters replying the the KGMB broadcasts.
gl
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So what you are sugesting is that AE's loop antenna was capable of receiving voice signals, this assumes that the KGMB was by voice, yet she didn't receive/reply to Itasca's voice transmissons. Strange!
Not at all strange. The loop is just an antenna. It can receive voice just as well as code. KGMB was (and still is) a commercial broadcast station. Their broadcasts were in voice. Earhart didn't hear Itasca's voice transmissions because she was listening for them on her missing belly antenna.
The question then becomes was the Itasca's radios operating correctly?
Itasca's transmitter seems to have been working correctly but there is considerable evidence that there were problems with the ship's receiver or receiving antenna system. Itasca did not hear some of the post-loss signals that other stations (including Howland and Baker) did hear.
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Did Brandenburg do an analysis of the probability of Earhart on Gardner being able to hear the 1 kw signal from KGMB at the times that she would have needed to hear it in order to reply to it.
Yes. Bob reports:
The Signal to Noise Ration (SNR) was 56.6 dB/Hz. The SNR required for 90% understandability of words and phrases is 45 dB/Hz, so the KGMB signal at Gardner was nearly 12 dB above the required level. Since the SNR is well above the required level, we can safely say the probability of Earhart being able to hear KGMB was close to 100%.
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"The post-loss radio signals are the elephant in the room that can no longer be ignored."
*pictures Tom Crouch shaking his head in a dismissive way and sayiing something along the lines of, "Impossible!" in a dismissive and/or condescending tone, based solely on observations gleaned during multiple watchings of Finding Amelia*
That is NOT an elephant, Mr. Gillespie. That is, a, ummmm, largish gray thingy, you probably didn't see it because you weren't looking at the right spot at the right time of day, no, sunspots! Yeah, that's it, sunspots got in the way! Anyway, definitely not an elephant ... Nothing to see here folks, move along, please ...
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This is indeed an excellent compilation of radio transmissions. After reading through them all, I do have a question.
Several amateur reports from the west coast (usually claimed to be heard on 3105) are dismissed as "not credible" with one reason being that no one in the central Pacific who was much closer to the source and specifically listening on that frequency heard them. Yet reports from people like Mabel Larremore in Texas, Nina Paxton in Kentucky, Mrs. Crabb in Toronto (July 5 & 6), Betty Klenck in Florida, and Thelma Lovelace in New Brunswick (while confirmed or presumed to be listening to harmonic frequencies of 3105) are considered credible even though no nearby Pacific stations heard anything. Shouldn't these Pacific locations have heard something on 3105 around the same time as well? I'd be tempted to demote at least some of these to "uncertain" since they are so isolated in time from signals received by other stations.
These amateur reports are among the strongest considering there were numerous locations in and around the Pacific that reported signals near the same time:
~1500Z July 4: Dana Randolph in Wyoming and Mrs. Crabb in Toronto simultaneously with Pan Am stations at Midway and Oahu
~0915Z July 5: Howard Coons in San Francisco within minutes of Navy stations at Howland, Baker, and San Francisco Division
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Several amateur reports from the west coast (usually claimed to be heard on 3105) are dismissed as "not credible" with one reason being that no one in the central Pacific who was much closer to the source and specifically listening on that frequency heard them. Yet reports from people like Mabel Larremore in Texas, Nina Paxton in Kentucky, Mrs. Crabb in Toronto (July 5 & 6), Betty Klenck in Florida, and Thelma Lovelace in New Brunswick (while confirmed or presumed to be listening to harmonic frequencies of 3105) are considered credible even though no nearby Pacific stations heard anything. Shouldn't these Pacific locations have heard something on 3105 around the same time as well?
Receptions of a signal at the same time by multiple stations is certainly a big credibility plus but it rarely happened, even among stations in the Central Pacific. In truth, Itasca and Coast Guard Hawaiian Section (COMHAWSEC) were the only stations in the Central Pacific maintaining a constant watch on 3105. Pan Am, Navy Wailupe, and Navy Tutuila listened from time to time but had other business to tend to. Itasca missed messages it should have heard (apparently had receiver or antenna problems) and COMHAWSEC was a long way from Gardner. When Itasca heard unintelligible voice, COMHAWSEC either heard nothing or just a carrier wave.
In other words, lack of simultaneous reception by other stations is not a enough to throw a signal into the "uncertain" category. The amateurs we consider to be credible have both quantitative and qualitative factors in their favor. The frequency and probability are in the credible range and the content of the reported messages are consistent with known constraints.
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Your points are well taken, which leads to the question of whether other stations hearing anything around the same time is even a valid criterion in the first place. My fear is that the overall work compiled by you and Mr. Brandenburg might be discounted by naysayers because of the seeming double standard in how credibility is determined. I don't believe you are doing this at all, but I could see others who are promoting their own theories making the argument that reports supporting the Gardner hypothesis are deemed "credible" while any that contradict it are deemed "not credible." On the contrary, I believe you've made a convincing case that the aggregate of these reports supports the case of a landing at Gardner regardless of whether individual examples like Betty Klenck or Mabel Larremore are labeled as "credible" or "uncertain."
Here are some ideas that might strengthen the overall quality of the catalog:
1) Perhaps the "Qual Factors" could be clearly broken into pros and cons listing factors in favor of the transmission being a legitimate Earhart message and those opposed. Whether it be the "LA hoaxers" and Charles Miguel or Betty, Mabel, Nina, etc., lack of reception by other stations around the same time would be a con. The former group has additional factors against it while the latter has other factors in favor which help make a more balanced judgement of credibility.
2) I think I struggle with the concept of "credible" because it is so binary. Something can be barely credible or extremely credible yet it is "graded" equally in the catalog. Another idea to consider is changing from "credibility" to "level of confidence" that the signal was from the Electra. This could include 4 levels instead of the 3 used now:
- High: Probability of reception is good (maybe >0.2) and there are several qualitative factors that would be considered "pros" far outweighing the "cons" against it. These would be the stronger of the reports listed as "credible."
- Medium: Probability of reception is plausible (maybe 0.001 to 0.2) and the "pros" seem to outweigh the "cons." These would be the weaker of the reports listed as "credible."
- Low: Probability of reception is low and/or pros and cons are roughly equal. These are the reports called "uncertain."
- None: Probability is essentially 0 and/or cons far outweigh the pros. These are report now called "not credible."
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Jeff,
The question of whether other stations heard something around the time of a signal is relevant in some circumstances, but not all. For example, a report by a source in the continental U.S. claiming to have heard Earhart on 3105 would be suspect if none of the numerous airport stations listening 24/7 on that frequency heard it. On the west coast, COMFRANDIV had a dedicated 24/7 watch on 3105 and 6210, using high-gain antennas aimed at Hawaii -- and by extension the central Pacific -- and it would be extremely unlikely for some one on the coast to hear a signal on either frequency without COMFRANDIV hearing it.
The notion of degrees of credibility related to reception probability suggests confusion about the meaning of probability. The probability in the catalog reflects the factors affecting signal-to-noise ratio (SNR) at the receiver at the time. For example, a probability of 0.002 means that, given the ionospheric conditions at the time, random variability in propagation factors would cause the SNR to rise above the reception threshold on 2 occasions out of 1,000. But whether the event in question was believably one of the 2 times depends on the reported signal content, reporting party credibility, etc.
If a signal was heard, it was heard regardless of the propagation probability. A signal on a low probability path can fade in briefly, or for an extended time, then disappear. A signal on a high probability path can fade out. International shortwave broadcasters minimize fading dropouts of their signals by transmitting at power levels on the order of tens of thousands of watts to overcome fading. Earhart's low-power signals were at the mercy of the propagation conditions.
The idea of degrees of credibility is superficially attractive, but unworkable. Ric and I went through this some time ago. Credibility, like pregnancy, is inherently binary. Either we believe something or we don't. The credibility criteria in the catalog are essentially subjective, but when applied they yield a binary result. Assigning intermediate degrees of credibility, based on whatever criteria, opens the door to endless quibbling about the appropriate degree for a given case, and what difference it makes.
Bob
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My fear is that the overall work compiled by you and Mr. Brandenburg might be discounted by naysayers because of the seeming double standard in how credibility is determined.
Naysaying is a mind set. I've seen it at work among our own researchers and have come to understand that it has little to do with facts or reason. I've stopped worrying about naysayers.
I don't believe you are doing this at all, but I could see others who are promoting their own theories making the argument that reports supporting the Gardner hypothesis are deemed "credible" while any that contradict it are deemed "not credible." On the contrary, I believe you've made a convincing case that the aggregate of these reports supports the case of a landing at Gardner regardless of whether individual examples like Betty Klenck or Mabel Larremore are labeled as "credible" or "uncertain."
"Uncertain" is not a lesser grade of "credible." When we say "uncertain" we're saying that there is not enough information to make a judgement about credibility.
You're right, it's the aggregate of all the findings that makes the case. Our analysis tests the hypothesis that the signals came from the Earhart plane parked on the reef at Gardner. In no case is the credibility of a signal influenced by whether or not it supports that hypothesis. It happens that all of the credible signals could have been sent from the reef at Gardner. The hypothesis is therefore supported. Of course, some other unstated and untested hypothesis might also be supported but would have to pass the same rigorous tests.
1) Perhaps the "Qual Factors" could be clearly broken into pros and cons listing factors in favor of the transmission being a legitimate Earhart message and those opposed. Whether it be the "LA hoaxers" and Charles Miguel or Betty, Mabel, Nina, etc., lack of reception by other stations around the same time would be a con. The former group has additional factors against it while the latter has other factors in favor which help make a more balanced judgement of credibility.
Right now we discuss the "Qual Factors" for each signal in a short narrative paragraph.
We could, I suppose, replace the paragraph with a checklist of pros and cons with each factor being assigned a value. Some factors would be "gatekeepers" that are by nature binary.
Frequency? The message must have been heard on 3105, 6210 or a harmonic of those frequencies. If it wasn't it's an automatic "Not Credible."
Well-sent code? Automatic "Not Credible."
Description of a floating airplane? Automatic "Not Credible."
And so forth.
Other factors are trickier and would require that we assign a range of values that would be, by definition, arbitrary. For example,
- What is simultaneous reception by another station worth? One positive point? Five positive points?
- What is it worth if dashes are heard immediately following a request for dashes? One positive point? Five positive points?
- What if an otherwise credible amateur later changes her story, as Paxton did, to include information that is not credible? One negative point? Five negative points?
The result would be to make each catalog entry interminably long and create the impression that we're trying to quantify factors that are unavoidably qualitative. The catalog cannot hope to present the entire case for or against each signal. Naysayers will undoubtedly dismiss our conclusions about the post-loss radio signals with generalities just as they do with our archival evidence and artifacts. We can defend our evaluation of any signal with reams of specifics. I think it's best to leave our "Qual Factors" just as they are.
2) I think I struggle with the concept of "credible" because it is so binary. Something can be barely credible or extremely credible yet it is "graded" equally in the catalog. Another idea to consider is changing from "credibility" to "level of confidence" that the signal was from the Electra.
I'm not sure you understand what we mean by "credible." It does not mean “proven to be authentic.” The only way to prove that a signal was an authentic communication from Amelia Earhart would be to ask her if she sent it and, given our aversion to psychics, we haven't found a way to do that. "Credible" means we haven't found a reason that it couldn't be a genuine signal from the Electra. There are no gradations. Either the message is disqualified or it's not.
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Sooooo, just out of curiosity, what, if anything, does Tom Crouch have to say about these signals?
LTM,
Monty Fowler
TIGHAR No. 2189CE
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Sooooo, just out of curiosity, what, if anything, does Tom Crouch have to say about these signals?
I wasn't going to mention this but, since you ask -
During our BBC Radio debate the presenter asked Tom for his opinion about Betty's Notebook. Tom said something like the same thing he said on the Discovery Channel show.
"I just have a hard time believing that this 15 year-old girl in Florida was the ONLY person in the world who heard a distress call from Amelia Earhart."
To which I responded, "But Tom, she wasn't."
"She wasn't?"
"No Tom, there were at least eight other people who accidentally heard credible distress calls from Earhart on a harmonic of her primary frequencies, not to mention the dozens of credible signals heard on the primary frequencies by professional operators throughout the Central Pacific."
The BBC edited that entire exchange out of the program they aired. You just can't have your Smithsonian expert skeptic looking totally ignorant of the subject he's being expertly skeptical about.
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TIGHAR No. 2189CER ... who puzzled over the added "R" for a good 20 minutes before it dawned on him that it stood for Researcher.
OMG! The code has been broken!
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I agree with you Ric... Each and every member worked on getting all these radio transmission's into 1 very easy place all together for us really deserve a big Huge Thank's from all of us...They did a wonderfull job on this project..
I am just a Tech. Class Ham Radio operator.. And I only got a homemade 2 little small copper wire's between 3 trees in my back yard and I pick up some amazing far away stations across the Northern American Continent and a lot in many foreign language I can't understand..
Power of them radio wave's traveling so far away will amaze you quickly on real good nights for radio waves.. Most of them are on what is called down on the low band range...
Just wanted to say Thank You to them members who did all that good and wondefull work for us..
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Folks,
Trying to get the signal times sorted out in my head.
I see that today, Niku is Zulu (GMT) +13; was that the case in 1937 as well?
Entry 1 in the Post Loss Radio Signal Catalog (http://goo.gl/td1sm) gives Zulu 0006 July 3, Gardner 1306 July 2 (Zulu -11). Should this be July 3, which would make Gardner Zulu +13?
Entry 2 gives Zulu 0010 July 3, Gardner 1310 July 3, which seems like the correct offset (Gardner=Zulu+13).
Entry 3 is back to 0200 July 3, Gardner 1500 July 2 (Zulu -11)
Entries 4-15 continue with Gardner July 2; entry 16 is July 3; entries 17-21 go back to July 2; entry 22 is July 3; entries 23-43 are July 2.
Entry 42 gives Zulu 1115 July 2, Gardner 0015 July 2 for offset of Zulu -11, yet entry 43 gives Zulu 1119 July 3, Gardner 2319 July 2 for an offset of Zulu -12.
The remainder are for the most part Zulu -11.
GMT right now gives 4:08 a.m. Tuesday, and Niku gives 5:08 p.m. Tuesday, again for an offset of Zulu +13.
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Folks,
Trying to get the signal times sorted out in my head.
I see that today, Niku is Zulu (GMT) +13; was that the case in 1937 as well?
Entry 1 in the Post Loss Radio Signal Catalog (http://goo.gl/td1sm) gives Zulu 0006 July 3, Gardner 1306 July 2 (Zulu -11). Should this be July 3, which would make Gardner Zulu +13?
Entry 2 gives Zulu 0010 July 3, Gardner 1310 July 3, which seems like the correct offset (Gardner=Zulu+13).
Entry 3 is back to 0200 July 3, Gardner 1500 July 2 (Zulu -11)
Entries 4-15 continue with Gardner July 2; entry 16 is July 3; entries 17-21 go back to July 2; entry 22 is July 3; entries 23-43 are July 2.
Entry 42 gives Zulu 1115 July 2, Gardner 0015 July 2 for offset of Zulu -11, yet entry 43 gives Zulu 1119 July 3, Gardner 2319 July 2 for an offset of Zulu -12.
The remainder are for the most part Zulu -11.
GMT right now gives 4:08 a.m. Tuesday, and Niku gives 5:08 p.m. Tuesday, again for an offset of Zulu +13.
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I understand your confusion because I just checked the first three entries and they all have errors in the time conversions. Assuming that the Zulu time is correct then the Gardner time for the the first three entries should be 1206 July 2nd; 1210 July 2nd; and 1400 July 2nd. It is also possible that the Zulu times are not correct depending how they were arrived at, making an erroneous correction from local times. Just glancing at more of the listings at random, it appears that most of them use the incorrect conversion from Zulu to Gardner time making Gardner time 11 hours slow on Zulu when the correct difference for the standard time zone in which Gardner is located is 12 hours behind Zulu.
Standard time zones run from - 12 to +12 and are whole hours. For convenience, some areas may keep their clocks set to some other number and in 1937 Hawaii kept their clocks set to 10:30 behind on GMT but this was an exceptional case. There are other examples of this. No country set their clocks 13 hours ahead of Zulu until the year 1999 when the island nation of Kiribati, which includes Niku, decided to switch from 12 hours behind Zulu, which is the correct time zone for Niku, to 13 hours ahead of Zulu so that they would be the first country to enter the new millennium because the year 2000 would then arrive there prior to any other place on earth which they thought would bring in tourists. This is a completely new and non-standard way of keeping time and did not exist in 1937.
I posted the following message on August 29th: (the sign of the Zone Descriptions, Z.D., indicate the correction to local time to compute Zulu time and is the convention used by navigators and by the Navy and Coast Guard. I see by your posting that your use the opposite convention for the sign of the correction which is what you would use to compute local time starting from Zulu, hopefully this will not be too confusing for you. )
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Question:
"while thinking about the post loss messages. i considered a couple of things. what time would it have been on Nicu? at the times the message were recieved by dana on the fourth? and then when betty heard the other message."
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My response:
"That's kind of a nonsensical question. "Time" is a human construct so has no meaning on an uninhabited island since the land crabs do not wear watches. People choose whatever "time" is convenient for them. In the olden days every town kept its own time with towns further east seeing the sun rise before towns further west so their clocks were ahead and displayed a later time. With the arrival of railroads it became necessary to coordinate schedules across distances east and west so the concept of "zone time" was invented. Standard time zones are 15 ° wide because the sun travels 15° west every hour so this makes the "zone times" differ by exact hours. They extend 7.5 degrees (7° 30') each way from the standard meridians (which are spaced every 15° starting with the Greenwich Meridian) for that zone. This is the system used at sea but is often modified on land for convenience by not using the exact dividing lines between zones so that entire political units, such as states , can be on the same time and also some countries change their time to "daylight savings time" in the summer. So, for example, the standard meridian for the time in California is 120° west longitude and the zone extends from 112.5° (112° 30') to 127.5° (127° 30') west. To make it easy to convert from a zone time to GMT ("Z" time, or Zulu time) the zones are given numbers (called "Zone Descriptions, Z.D.) that you add to the zone time to find GMT. For California time it is + 8 so you add eight hours to California clocks to find Zulu time. (It changes for daylight savings time to + 7, but only in the U.S. It remains + 8 at sea.)
There is an exception in that there are two zones, each only 7.5° wide (7° 30'), abutting the 180th meridian. To the east the Z.D. is + 12 while to the west it is - 12 to account for the clocks saying the same time in each of these zones but the date being different. An example will make this clear. If you are at 174° 30'east longitude (west of the 180th, Z.D. - 12) on July 3rd and your clock says 2100 you subtract 12 hours and the GMT is 0900 on July 3rd. If you are at 174° 30' west longitude (on Gardner) (east of the 180th, Z.D. + 12) your clock also says 2100 but your calender says July 2nd. You add 12 hours and and find the same answer, 0900 the next day, July 3rd.
The clocks are set for convenience which is why the people on Howland kept their clocks set with a Z.D. of + 10:30 so as to keep the same time as that being kept in Hawaii for convenience of radio schedules. Hawaii was an exception and kept time with a Z.D. of + 10:30 because Hawaii is near the dividing line between two time zones and keeping time using either of those standard zones would cause their clocks to always be in disagreement with the sun, noon would never happen at 12:00 o'clock. Note, there was no such thing as "half-hour time zones," ships at sea at the same longitude of Hawaii kept their clocks set to the standard zone time with a Z.D. of + 10. (Hawaii now uses the standard time zone with Z.D. of + 10.)
U.S. Navy Regulation, Article 1031 issued in 1920 required Navy vessels to keep time based on the standard time zones. Paragraphs 6e and 8 however gave the commander the authority to set his clocks in a non-standard way (but he must note in the logbook the exact "hours, minutes and seconds" needed to convert ship's time to GMT as the Z.D.) when near a shore that kept non-standard time or under circumstances that "may render desirable a departure from the regular method." Itasca used this authority and kept time thirty minutes fast from the standard time zone for its location (+ 12), but Itasca was not keeping time in conformance non-existent "half hour time zones". A half hour zone would be 3.75 degrees (3° 45') wide so in such a system the + 12 hour zone would extend from 176.25° (176° 15') west longitude to the 180th meridian. If they had been using "half hour time zones" then both Howland and the Itasca would have been in the +12 "half hour zone" since they were at 176.6° (176° 38') west longitude, only 3.4° east of the 180th meridian. Itasca kept their clocks set to Z.D. + 11:30 for their own convenience (probably to keep their time exactly one hour different than Hawaii's to avoid confusion with radio schedules too.)
So what time was it on Gardner? Its longitude is 174.5° (174° 32') west so the Z.D. there is + 12 for that standard time zone and Earhart did not know that Itasca was using a Z.D. of + 11:30 so she would have had no reason to use that Z.D. But there is no reason to believe anybody on Gardner kept either of these zone times. If Earhart landed on Gardner then her time, the time on the cockpit clock, would be the same as Lae time, Z.D. -10, since her practice was to leave her clock set to the time at the departure airport. If Noonan looked at his chronometers then the time was GMT since his were set to GMT for navigational purposes."
https://tighar.org/smf/index.php/topic,433.0.html
gl
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Just glancing at more of the listings at random, it appears that most of them use the incorrect conversion from Zulu to Gardner time making Gardner time 11 hours slow on Zulu when the correct difference for the standard time zone in which Gardner is located is 12 hours behind Zulu.
But isn't Gardner/Niku 13 hours ahead of Zulu (UTC +13)?
Zulu as of this posting is 1419 Tuesday; Gardner/Niku is 1519 Wednesday.
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Ah...does any of the confusion lie in the difference between Howland and Gardner?
Howland is often listed -12, whereas Phoenix Group is generally +13.
Howland is listed as "Howard" on this map:
(http://farm7.static.flickr.com/6099/6280261300_9eaa29499a_z.jpg)
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The Kiribati Adjustment of 1994/95
The location of the IDL since 1995
The most recent major adjustment of the International Date Line was announced in 1994 by the government of Kiribati.
For many years the International Date Line, that for historic reasons bisected the island republic into two halves, had been viewed as an annoying economic nuisance. The western part of the republic was always 24 hours ahead of its eastern part, and there were only four days in each week when official business could be conducted between both parts. To put an end to this situation, Teburoro Tito (the president and foreign minister of Kiribati from 1994 to 2003) announced that on 1 January 1995 the International Date Line would henceforth run along the many-cornered eastern boundary of the republic. It was only realized afterwards that the Kiribati’s most easterly islands would then become serious contenders in the race of which place in the Pacific would first to greet the rays of the rising sun at the begin of the third millennium.
The Kiribati adjustment has given the International Date Line, which during most of the 20th century had remained relatively close to the 180º meridian, a very noticeable eastward protrusion.
However, since the Kiribati adjustment of the International Date Line, many map- and chart makers still publish maps and atlases that depict the former location of the International Date Line. Although the most recent issues of the Standard Time Zones chart compiled by the Nautical Almanac Office (printed in the annual Astronomical Phenomena and available online from the World Time Zone web page of the U.S. Naval Observatory) are aware that Kiribati observes the Asian day count, the International Date Line is locally still drawn as a straight line through the island group.
Time zones map for 2007
Many internet sites on time zones and the International Date Line still give incomplete or out-dated information, one of the very few that does give a correct depiction is www.worldtimezone.com.
http://www.astro.uu.nl/~vgent/idl/idl_kiribati.htm
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I understand your confusion because I just checked the first three entries and they all have errors in the time conversions.
No, they are correct.
Assuming that the Zulu time is correct then the Gardner time for the the first three entries should be 1206 July 2nd; 1210 July 2nd; and 1400 July 2nd.
The Zulu times are correct and the local Gardner times are correct for the 1937 context.
It is also possible that the Zulu times are not correct depending how they were arrived at, making an erroneous correction from local times. Just glancing at more of the listings at random, it appears that most of them use the incorrect conversion from Zulu to Gardner time making Gardner time 11 hours slow on Zulu when the correct difference for the standard time zone in which Gardner is located is 12 hours behind Zulu.
No. The best conversion for Gardner in the context of U.S. Navy practice in 1937 was Greenwich Civil Time (as it was called then) minus 11 hours.
Standard time zones run from - 12 to +12 and are whole hours. For convenience, some areas may keep their clocks set to some other number and in 1937 Hawaii kept their clocks set to 10:30 behind on GMT but this was an exceptional case. There are other examples of this. No country set their clocks 13 hours ahead of Zulu until the year 1999 when the island nation of Kiribati, which includes Niku, decided to switch from 12 hours behind Zulu, which is the correct time zone for Niku, to 13 hours ahead of Zulu so that they would be the first country to enter the new millennium because the year 2000 would then arrive there prior to any other place on earth which they thought would bring in tourists. This is a completely new and non-standard way of keeping time and did not exist in 1937.
True, but irrelevant to the Post-Loss Radio Signals Catalog which calculates time in the 1937 context.
U.S. Navy Regulation, Article 1031 issued in 1920 required Navy vessels to keep time based on the standard time zones. Paragraphs 6e and 8 however gave the commander the authority to set his clocks in a non-standard way (but he must note in the logbook the exact "hours, minutes and seconds" needed to convert ship's time to GMT as the Z.D.) when near a shore that kept non-standard time or under circumstances that "may render desirable a departure from the regular method." Itasca used this authority and kept time thirty minutes fast from the standard time zone for its location (+ 12), but Itasca was not keeping time in conformance non-existent "half hour time zones". A half hour zone would be 3.75 degrees (3° 45') wide so in such a system the + 12 hour zone would extend from 176.25° (176° 15') west longitude to the 180th meridian. If they had been using "half hour time zones" then both Howland and the Itasca would have been in the +12 "half hour zone" since they were at 176.6° (176° 38') west longitude, only 3.4° east of the 180th meridian. Itasca kept their clocks set to Z.D. + 11:30 for their own convenience (probably to keep their time exactly one hour different than Hawaii's to avoid confusion with radio schedules too.)
The question is not what the regulations say. The question is what was actually done. You are correct in that U.S. Navy Regulation, Article 1031 did not specify the use of half hour time zones but, in actual practice, the use of half hour zones was quite standard - at least at the time of the Earhart disappearance. Itasca was merely following standard practice.
If you exam the deck logs of Colorado and Swan you'll find the Zone Description consistently changed by half-hour increments during their respective voyages and often in a fairly arbitrary manner. For example, Colorado left Pearl Harbor on July 4 using -10.5, switched to -11 the next day and remained at -11 when it refueled Itasca on July 7 when it was around 174° W (same longitude as Gardner). The battleship switched to -11.5 on July 8 when it was around 175° W and stayed at -11.5 throughout its search of the Phoenix Group even though it was back in the 174° area and continued to use -11.5 until July 15 when it switched to -10.5 in the 162° area shortly before arriving back at Pearl.
Swan also used half hour times zones on its travels. On the night July 5/6 it passed through 174° (same longitude as Gardner) using -11.
In 1939, Swan's sister ship Pelican visited Gardner to take aerial photos of the island with its Grumman J2F Duck as part of the Bushnell survey. It used -11. Clearly, Greenwich minus 11 is the best calculation of local time at Gardner in the historical context.
Note: All of the deck logs use "plus" instead of "minus" because they're talking about converting from local to Greenwich whereas we're talking about converting from Greenwich to local.
So what time was it on Gardner? Its longitude is 174.5° (174° 32') west so the Z.D. there is + 12 for that standard time zone and Earhart did not know that Itasca was using a Z.D. of + 11:30 so she would have had no reason to use that Z.D. But there is no reason to believe anybody on Gardner kept either of these zone times. If Earhart landed on Gardner then her time, the time on the cockpit clock, would be the same as Lae time, Z.D. -10, since her practice was to leave her clock set to the time at the departure airport. If Noonan looked at his chronometers then the time was GMT since his were set to GMT for navigational purposes.
I don't know what your source is for Earhart setting her cockpit clock to local time at the departure airport, but I do know that she told Itasca to use GCT for radio schedules during the Lae/Howland flight (an instruction that Itasca ignored). How AE and FN calculated local time on Gardner, if they bothered, is both unknowable and irrelevant. We included the best available calculation of local time on Gardner in the 1937 context primarily to provide a sense of the time of day for the reader. If Amelia and Fred thought it was 10 P.M. when we say it was 9 P.M. it has no bearing on the credibility of a radio signal heard at that time as long as the Zulu (Greenwich) time is correct.
BTW, we use Zulu as local time for signals heard by Pan Am stations at Mokapu, Midway, and Wake because Pan American, alone among all the stations involved, kept their radio schedules in Greenwich time. They were way ahead of the game.
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Entry 1 (30006IA) gives Zulu 0016 July 3; Gardner 1306 July 2
Entry 2 (30010IA) gives Zulu 0010 July 3; Gardner 1310 July 3
I'm just trying to understand why Gardner is July 2 in one case and July 3 in the other.
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Entry 1 (30006IA) gives Zulu 0016 July 3; Gardner 1306 July 2
Entry 2 (30010IA) gives Zulu 0010 July 3; Gardner 1310 July 3
I'm just trying to understand why Gardner is July 2 in one case and July 3 in the other.
That's a typo in Entry 2. Should be Gardner 1310 July 2. We'll fix it. That's the beauty of the internet. It's easy to fix mistakes.
We proofed and proofed and thought we caught everything but something always slips by. Let us know if you see anything else that doesn't make sense. Skeptical review is the essence of scientific rigor. Who knows? Even Gary may find a mistake. ::)
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Here are the entries in "Messages July 3, 1 – 47" (http://goo.gl/Pqm2x) where Gardner is listed as something other than -11:
Entry 2: Zulu 0010 July 3; Gardner 1310 July 3 [+13] (should be Gardner 1310 July 2?)
Entry 16: Zulu 0600 July 3; Gardner 1900 July 3 [+13] (should be Gardner 1900 July 2?)
Entry 22: Zulu 0608 July 3; Gardner 1908 July 3 [+13] (should be Gardner 1908 July 2?)
Entry 26: Zulu 0727 July 3; Gardner 1927 July 2 [-12] (should be Gardner 2027 July 2?)
Entry 31: Zulu 0835 July 3; Gardner 1935 July 2 [-13] (should be Gardner 2135 July 2?)
Entry 33: Zulu 0840 July 3; Gardner 2130 July 2 [-11:10] (should be Gardner 2140 July 2?)
Entry 38: Zulu 0916 July 3; Gardner 2116 July 2 [-12] (should be Gardner 2216 July 2?)
Entry 40: Zulu 0958 July 3; Gardner 2158 July 2 [-12] (should be Gardner 2258 July 2?)
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Here are the entries in "Messages July 3, 1 – 47" (http://goo.gl/Pqm2x) where Gardner is listed as something other than -11:
Thanks Sheila. We'll take a look at those and change them - or if we think they're right we'll explain why.
We want this thing to be right in every respect.
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Here are the entries in "Messages July 3, 1 – 47" (http://goo.gl/Pqm2x) where Gardner is listed as something other than -11:
Entry 2: Zulu 0010 July 3; Gardner 1310 July 3 [+13] (should be Gardner 1310 July 2?)
Entry 16: Zulu 0600 July 3; Gardner 1900 July 3 [+13] (should be Gardner 1900 July 2?)
Entry 22: Zulu 0608 July 3; Gardner 1908 July 3 [+13] (should be Gardner 1908 July 2?)
Entry 26: Zulu 0727 July 3; Gardner 1927 July 2 [-12] (should be Gardner 2027 July 2?)
Entry 31: Zulu 0835 July 3; Gardner 1935 July 2 [-13] (should be Gardner 2135 July 2?)
Entry 33: Zulu 0840 July 3; Gardner 2130 July 2 [-11:10] (should be Gardner 2140 July 2?)
Entry 38: Zulu 0916 July 3; Gardner 2116 July 2 [-12] (should be Gardner 2216 July 2?)
Entry 40: Zulu 0958 July 3; Gardner 2158 July 2 [-12] (should be Gardner 2258 July 2?)
[/quote
--------------------
But, using your sign convention, Gardner should be -12.
Entry 2: Zulu 0010 July 3; Gardner 1310 July 3 [+13] (should be Gardner 1210 July 2)
Entry 16: Zulu 0600 July 3; Gardner 1900 July 3 [+13] (should be Gardner 1800 July 2)
Entry 22: Zulu 0608 July 3; Gardner 1908 July 3 [+13] (should be Gardner 1808 July 2)
Entry 26: Zulu 0727 July 3; Gardner 1927 July 2 [-12] (should be Gardner 1927 July 2)
Entry 31: Zulu 0835 July 3; Gardner 1935 July 2 [-13] (should be Gardner 2035 July 2)
Entry 33: Zulu 0840 July 3; Gardner 2130 July 2 [-11:10] (should be Gardner 2040 July 2)
Entry 38: Zulu 0916 July 3; Gardner 2116 July 2 [-12] (should be Gardner 2116 July 2)
Entry 40: Zulu 0958 July 3; Gardner 2158 July 2 [-12] (should be Gardner 2158 July 2)
gl
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It's beyond me how anyone could consider that they were not alive and asking for help. And later to say ALL of these reports were "hoaxes". I was not alive in 1937, by a long shot..thank you, but I do not understand how these radio transmissions could have been discounted. Even in a 1937 mind set, it should have been obvious who they came from.
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But, using your sign convention, Gardner should be -12.
What do you mean by "sign convention?" Colorado, Swan, and Pelican all used -11 for the longitude of Gardner. That's what we used.
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http://www.nytimes.com/specials/magazine4/articles/earhart1.html
Amateurs Pick Up Signals
LOS ANGELES, July 2 (AP) -- Two amateur radio operators claimed to have picked up signals tonight on frequencies officially assigned to the plane of Amelia Earhart.
Walter McMenamy said he picked up weak signals on 6210 kilocycles at 6 P.M. (10 P.M. Eastern daylight time) and heard the letters "L-a-t" which he took to mean latitude. The letters were followed by indecipherable figures. The signals continued for some time. Mr. McMenamy expressed belief they came from a portable transmitter. He received other signals from a Coast Guard boat, presumably the cutter Itasca, requesting listeners to "stand by and listen on all frequencies."
At 8 P.M. (midnight Eastern daylight time), Carl Pierson, chief engineer of the Paterson Radio Corporation, picked up similarly weak signals on 3105 kilocycles, Miss Earhart's daytime frequency. He said they were erratic and indecipherable.
Both Mr. McMenamy and Mr. Pierson said the signals came from a hand-cranked generator. Miss Earhart carried one in her plane.
would a hand-cranked generator be enough to run radio ?
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But, using your sign convention, Gardner should be -12.
What do you mean by "sign convention?" Colorado, Swan, and Pelican all used -11 for the longitude of Gardner. That's what we used.
----------------------------------------
The Navy regulation in force since 1920 required that their ships maintain standard zone times but provided exceptions when it was operationally convenient to use a different, non-standard, offset from Zulu time. The standard correction factors for converting one time to another used by navigators and, by regulation, the Navy is to use the sign that will convert local time to Zulu time, this is called the "Zone Description" (Z.D.) and must be recorded in the log book and next to the clocks. Itasca kept their clock set to 11:30 slow on Zulu so to convert Itasca time to Zulu their Z.D. was +11.30. Other users however see the problem in the reverse sense and use a correction factor that will convert Zulu time to local time so they would call to correction factor for Itasca time as -11:30 which added to Zulu time will produce the local time kept on Itasca. That is what I meant by the different "sign conventions." Either method will work as long as you keep it straight and don't get confused.
The standard time zone that is 12 hours slow on Zulu time extends from longitude 172° 30' west longitude to the 180th meridian. Gardner is located at 174° 32' west longitude so falls squarely within this time zone as does Howland. The Z.D., therefore, for Gardner is +12 hours (and for those going the other way, -12 hours.) Apparently for operational convenience, such as maneuvering in an area where you might cross back and forth across the dividing line between two time zones or to coordinate between ships that may be close to each other but on different sides of the dividing line, the ships you mentioned decided to keep their clocks set to Z.D. + 11 hours. But this doesn't change the fact that the standard time on Gardner (if someone were there) would have been 12 hours slow on Zulu in 1937. Since you purpose was to allow your readers to have sense of the actual time on Gardner, using the non-standard time kept on those ships instead of the correct time at Gardner will cause a one hour error and noon will happen at 13:00 instead of 12:00, sunrise will be at 7:00 a.m. and sunset at 7:00 p.m. (instead of 6 a.m. and 6 p.m.) and will not be symmetrical around noon and this will also affect the local time for the tides which might be significant for the operation of the radios in the plane sitting on the reef.
We have seen that the Itasca, using the authority of the Navy regulation, set their clocks to a non-standard offset from Zulu, for their convenience, and did not maintain their clocks on the standard time zone in the vicinity of Howland which is 12 hours slow on Zulu, these other ships were doing the same thing.
gl
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The Navy regulation in force since 1920 required that their ships maintain standard zone times but provided exceptions when it was operationally convenient to use a different, non-standard, offset from Zulu time. The standard correction factors for converting one time to another used by navigators and, by regulation, the Navy is to use the sign that will convert local time to Zulu time, this is called the "Zone Description" (Z.D.) and must be recorded in the log book and next to the clocks. Itasca kept their clock set to 11:30 slow on Zulu so to convert Itasca time to Zulu their Z.D. was +11.30. Other users however see the problem in the reverse sense and use a correction factor that will convert Zulu time to local time so they would call to correction factor for Itasca time as -11:30 which added to Zulu time will produce the local time kept on Itasca. That is what I meant by the different "sign conventions." Either method will work as long as you keep it straight and don't get confused.
Ah, okay. I think the term "offset" generates confusion, too, since it implies (to my brain) "offset from Zulu." So a "-11" could either mean "Zulu -11 = local," or "local -11 = Zulu," correct?
And in 1937, Howland time was still different from Gardner/Niku time, correct?
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You keep citing regulations and I'll keep citing reality. The ships' logs consistently used half hour time zones when they were underway, far from land or other ships. Colorado, Swan and Pelican all used 11 hours when in the vicinity of Gardner's longitude. Gardner may have been square in the middle of the standard 12 hour Z.D. as you say but nobody seems to have used it. We decided to use what was actually used because we want to stay within the context of the actual events as much as possible. When you compile your own Post-Loss Radio Signals Catalog you can use 12 hours for local Gardner time if it makes you feel better.
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Maybe this view is better - 1936 map notes mention that this map shows:
• Time zone boundaries and clocks showing the time when it is midnight at Greenwich
(http://farm7.static.flickr.com/6056/6280279543_4f6ae7c687_z.jpg)
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And in 1937, Howland and Gardner were still in different time zones, correct?
According to Gary, Howland and Gardner were officially both in the 12 hour time zone. That's fine, but none of the ships used it.
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would a hand-cranked generator be enough to run radio ?
There was no hand-cranked generator. McMenamy and Pierson were hoaxers. It's in the catalog (http://tighar.org/Projects/Earhart/Archives/Research/ResearchPapers/Brandenburg/signalcatalog.html).
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And in 1937, Howland and Gardner were still in different time zones, correct?
According to Gary, Howland and Gardner were officially both in the 12 hour time zone. That's fine, but none of the ships used it.
Oops - I'd better qualify that - for our purposes both Howland and Gardner are -11 offset from Zulu, meaning 11 hours behind Zulu, correct? Zulu -11 = Howland local, and Zulu -11 = Gardner local?
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Oops - I'd better qualify that - for our purposes both Howland and Gardner are -11 offset from Zulu, meaning 11 hours behind Zulu, correct? Zulu -11 = Howland, and Zulu -11 = Gardner?
For the purposes of TIGHAR's Post-Loss Radio Signals Catalog we have used 11.5 behind Zulu for Howland (because that's what Itasca was using) and 11 hours behind Zulu for Gardner (because that's what the Navy most often used for that longitude).
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And in 1937, Howland and Gardner were still in different time zones, correct?
According to Gary, Howland and Gardner were officially both in the 12 hour time zone. That's fine, but none of the ships used it.
--------------------------------------------
That's fine but you stated your purpose was to let the reader know what the castaways would observe on Gardner, not what the sailors on ships operating in the vicinity would observe. Either you should not call it "Gardner time" or you should include a warning:
"WARNING, WHAT WE HAVE LISTED AS 'GARDNER TIME' IS ACTUALLY NOT WHAT WOULD HAVE BEEN OBSERVED ON GARDNER. IT IS ACTUALLY THE TIME OBSERVED ON NAVY SHIPS PARTICIPATING IN THE SEARCH AND IS ACTUALLY AN HOUR FAST ON WHAT WOULD HAVE BEEN OBSERVED BY EARHART AND NOONAN"
gl
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For the purposes of TIGHAR's Post-Loss Radio Signals Catalog we have used 11.5 behind Zulu for Howland (because that's what Itasca was using) and 11 hours behind Zulu for Gardner (because that's what the Navy most often used for that longitude).
Great - thank you!
Apparently the time zone intricacies wreaked some (extra) havoc during the war:
After GALVANIC was over and done...there was a very considerable amount of criticism from within the Navy raised over the inability of the landing boats to deliver Wave Four...on schedule.
The Sumner tide tables begin 15 January 1944. The ship's formula for high tide at Tarawa stated that, using zone+12 time, it occurred 2hrs 7min before high water at Apia, Samoa. The U.S. Coast and Geodetic Survey Tide Tables showed that this important event occurred (using zone-12 time) 3hrs 55 min before high water at Apia, Samoa. This is a sizeable variation in exact local times, even when the tide table of one day later is used.
http://www.ibiblio.org/hyperwar/USN/ACTC/actc-18.html
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Oops - I'd better qualify that - for our purposes both Howland and Gardner are -11 offset from Zulu, meaning 11 hours behind Zulu, correct? Zulu -11 = Howland, and Zulu -11 = Gardner?
For the purposes of TIGHAR's Post-Loss Radio Signals Catalog we have used 11.5 behind Zulu for Howland (because that's what Itasca was using) and 11 hours behind Zulu for Gardner (because that's what the Navy most often used for that longitude).
But the radio log kept by the radio operators actually ashore on Howland used Z.D. +10:30 not + 11:30.
gl
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That's fine but you stated your purpose was to let the reader know what the castaways would observe on Gardner, not what the sailors on ships operating in the vicinity would observe.
That's not what I said. I said, "We included the best available calculation of local time on Gardner in the 1937 context primarily to provide a sense of the time of day for the reader." By "sense of time of day" I mean early morning, late morning, afternoon, evening, late at night, etc. That's hard to get from Zulu time.
Either you should not call it "Gardner time" or you should include a warning:
"WARNING, WHAT WE HAVE LISTED AS 'GARDNER TIME' IS ACTUALLY NOT WHAT WOULD HAVE BEEN OBSERVED ON GARDNER. IT IS ACTUALLY THE TIME OBSERVED ON NAVY SHIPS PARTICIPATING IN THE SEARCH AND IS ACTUALLY AN HOUR FAST ON WHAT WOULD HAVE BEEN OBSERVED BY EARHART AND NOONAN"
We don't know, and don't have any way of knowing, what local time Earhart and Noonan "observed" on Gardner - nor does it matter. To include the statement you suggest would be to assert that we know something we can not possibly know. In historical writing "would have" is a guess masquerading as fact. We have had this discussion before. If you ever catch me pulling a "would have" jump all over me. It's one of the most dangerous mistakes an investigator can make.
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But the radio log kept by the radio operators actually ashore on Howland used Z.D. +10:30 not + 11:30.
Sorry. I misspoke. We use +11:30 for Itasca. We use +10:30 for Howland for the reason you cite.
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Maybe this view is better - 1936 map notes mention that this map shows:
• Time zone boundaries and clocks showing the time when it is midnight at Greenwich
(http://farm7.static.flickr.com/6056/6280279543_4f6ae7c687_z.jpg)
-------------------------------
You have to look at the clock images at the bottom of the map to see the time for that particular time zone. The clock images you noticed are the exceptions to the standard time kept only on the land located next to those clock faces.
gl
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I don't know what your source is for Earhart setting her cockpit clock to local time at the departure airport, but I do know that she told Itasca to use GCT for radio schedules during the Lae/Howland flight (an instruction that Itasca ignored). How AE and FN calculated local time on Gardner, if they bothered, is both unknowable and irrelevant. We included the best available calculation of local time on Gardner in the 1937 context primarily to provide a sense of the time of day for the reader. If Amelia and Fred thought it was 10 P.M. when we say it was 9 P.M. it has no bearing on the credibility of a radio signal heard at that time as long as the Zulu (Greenwich) time is correct.
BTW, we use Zulu as local time for signals heard by Pan Am stations at Mokapu, Midway, and Wake because Pan American, alone among all the stations involved, kept their radio schedules in Greenwich time. They were way ahead of the game.
---------------------------------
That's easy, Earhart's notes on the flight from Natal to Dakar.
gl
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But the radio log kept by the radio operators actually ashore on Howland used Z.D. +10:30 not + 11:30.
Sorry. I misspoke. We use +11:30 for Itasca. We use +10:30 for Howland for the reason you cite.
And this is Z.D., meaning Itasca +11:30 = Zulu, and Howland +10:30 = Zulu, correct?
Itasca was 11:30 behind Zulu; Howland was 10:30 behind Zulu
Done the other way, this would be Itasca -11.5 and Howland -10.5 (Itasca local = Zulu -11.5; Howland local = Zulu -10.5)
Whew.
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Non-Z.D. method (caculate local from Zulu) (What's correct term for this - offset?)
Itasca local: Zulu -11.5
Gardner local: Zulu -11
Howland local: Zulu -10.5
Z.D. method (calculate Zulu from local)
Itasca: Z.D. +11.5
Gardner: Z.D. +11
Howland: Z.D. +10.5
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Non-Z.D. method (caculate local from Zulu) (What's correct term for this - offset?)
Itasca local: Zulu -11.5
Gardner local: Zulu -11
Howland local: Zulu -10.5
Z.D. method (calculate Zulu from local)
Itasca: Z.D. +11.5
Gardner: Z.D. +11
Howland: Z.D. +10.5
--------------------------
For Gardner you state Ric's usage correctly. For the common usage however, not Ric's, it would be Zulu -12. If you don't believe me, just go to the bottom of the 1936 National Geographic Map that you posted, directly down from Gardner, where you will find a clock face displaying "12:00 NOON." The white vertical lines are the boundaries between the time zones. (Note that is is 12:00 NOON on both sides of the 180th meridian but the dates are different.)
gl
gl
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That's fine but you stated your purpose was to let the reader know what the castaways would observe on Gardner, not what the sailors on ships operating in the vicinity would observe.
That's not what I said. I said, "We included the best available calculation of local time on Gardner in the 1937 context primarily to provide a sense of the time of day for the reader." By "sense of time of day" I mean early morning, late morning, afternoon, evening, late at night, etc. That's hard to get from Zulu time.
Either you should not call it "Gardner time" or you should include a warning:
"WARNING, WHAT WE HAVE LISTED AS 'GARDNER TIME' IS ACTUALLY NOT WHAT WOULD HAVE BEEN OBSERVED ON GARDNER. IT IS ACTUALLY THE TIME OBSERVED ON NAVY SHIPS PARTICIPATING IN THE SEARCH AND IS ACTUALLY AN HOUR FAST ON WHAT WOULD HAVE BEEN OBSERVED BY EARHART AND NOONAN"
We don't know, and don't have any way of knowing, what local time Earhart and Noonan "observed" on Gardner - nor does it matter. To include the statement you suggest would be to assert that we know something we can not possibly know. In historical writing "would have" is a guess masquerading as fact. We have had this discussion before. If you ever catch me pulling a "would have" jump all over me. It's one of the most dangerous mistakes an investigator can make.
----------------------------------
Since I was talking about natural phenomena on which there can be no disagreement, such as the earth rotating on its axis, the sun rising in the east, etc. you are right, Ric, I should not have used the conditional tense with the formulation, "WOULD HAVE BEEN" but should have used simply "WAS." Here is the corrected warning for your index:
"WARNING, WHAT WE HAVE LISTED AS 'GARDNER TIME' IS ACTUALLY NOT WHAT WAS OBSERVED ON GARDNER. IT IS ACTUALLY THE TIME OBSERVED ON NAVY SHIPS PARTICIPATING IN THE SEARCH AND IS ACTUALLY AN HOUR FAST ON WHAT WAS OBSERVED BY EARHART AND NOONAN"
gl
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Gary,
Don't know if I should poke my nose in here BUT...
For Gardner you have Ric's usage correct. For the common usage, not Ric's, it would be Zulu -12.
You keep citing regulations and I'll keep citing reality. The ships' logs consistently used half hour time zones when they were underway, far from land or other ships.
I have fallen into this same trap and can tell you from experience that what the regulation states and what is actually done can and does differ. Some people don't know what the regulation states, some don't care what the regulation states, and some know what the regulation states but also knows what works and that is what they use. That is the "reality" Ric speaks of.
LTM,
Don
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Gary,
Don't know if I should poke my nose in here BUT...
For Gardner you have Ric's usage correct. For the common usage, not Ric's, it would be Zulu -12.
You keep citing regulations and I'll keep citing reality. The ships' logs consistently used half hour time zones when they were underway, far from land or other ships.
I have fallen into this same trap and can tell you from experience that what the regulation states and what is actually done can and does differ. Some people don't know what the regulation states, some don't care what the regulation states, and some know what the regulation states but also knows what works and that is what they use. That is the "reality" Ric speaks of.
LTM,
Don
--------------------
But the issue of what "time" to associate with Gardner has nothing to do with whether the ships were following regulation and it appears that they were following the exception contained in the regulation for operational convenience, which I agree is the correct thing for those ships to do. But for people reading the listing and wanting to know what time was observed on Gardner, basically what time the sun rose and set, the time of noon and of the tides, using those ships' time does not accurately depict what people on Gardner in July 1937 observed.
gl
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And in 1937, Howland and Gardner were still in different time zones, correct?
According to Gary, Howland and Gardner were officially both in the 12 hour time zone. That's fine, but none of the ships used it.
Oops - I'd better qualify that - for our purposes both Howland and Gardner are -11 offset from Zulu, meaning 11 hours behind Zulu, correct? Zulu -11 = Howland local, and Zulu -11 = Gardner local?
------------------------
I have attached table 36 from The American Practical Navigator, the standard navigational textual authority published by the the U.S. Navy Hydrographic Office as Publication Number 9 (H.O. 9). The American Practical Navigator has been accepted as the ultimate reference in the U.S. for well over a hundred years. This table shows the standard time zones and Zone Descriptions.
gl
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Here are the entries in "Messages July 3, 1 – 47" (http://goo.gl/Pqm2x) where Gardner is listed as something other than -11:
Thanks Sheila. We'll take a look at those and change them - or if we think they're right we'll explain why.
We want this thing to be right in every respect.
-------------------------
I don't plan to go over all the entries and I do thank you for your work on this project. But I do have a question about the third entry:
"Identifier 30200MC
Z Time/Date 0200 July 3
Local Time/Date 1800 PST July 2
Gardner Time/Date 1500 July 2
Agency/Person Walter McMenamy, radio amateur
Location Los Angeles "
My question is how was the Z time arrived at? Presumably you started with McMenamy's time, which was California time, and converted it to Z time. You did this by adding 8 hours to his 1800 and arrived at 2600 which is 0200 the next day, July 3rd. But this was in July and they were probably ( I am not sure of this) on daylight savings time so the correct Z.D. most likely should have been +7 making the correct Z time 0100 July 3rd and the time at Gardner (using your method) 1400 July 2nd and 1300 using the standard method.
gl
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...using those ships' time does not accurately depict what people on Gardner in July 1937 observed.
Pssst, Gary...there were no people living on Gardner in 1937 - except AE and FN - and it doesn't matter what local time they "observed." It does matter what time the sun rose and set and at what time the tides went in and out, but for that we use Greenwich time. We likewise use Greenwich when we're comparing what radio signals were heard by whom and when. Local time on Gardner is a non-issue. When the island was eventually settled, the people who lived there didn't observe official local time. When Paul Laxton was there in 1949 he was amazed to discover that the sun came up every day at exactly 6 A.M. until he discovered that everyone set their clocks to 6 A.M. when the sun came up.
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My question is how was the Z time arrived at? Presumably you started with McMenamy's time, which was California time, and converted it to Z time. You did this by adding 8 hours to his 1800 and arrived at 2600 which is 0200 the next day, July 3rd. But this was in July and they were probably ( I am not sure of this) on daylight savings time so the correct Z.D. most likely should have been +7 making the correct Z time 0100 July 3rd and the time at Gardner (using your method) 1400 July 2nd and 1300 using the standard method.
The question of whether a particular location was or was not using Daylight Savings Time in 1937 was an issue we had to address with all of the U.S. domestic reports. At that time, use of DST was spotty. Verifying the correct conversion was a pain but we did it. That's one of many reasons it took us twelve years to compile this thing. To say for sure what source we used to verify that L.A. was not on DST I'd have to dig back through the records. Please feel free to check our work.
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I don't know what your source is for Earhart setting her cockpit clock to local time at the departure airport,
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That's easy, Earhart's notes on the flight from Natal to Dakar.
In her notes Earhart writes, "9:41 Natal time. Clouds seem to be changing. (etc.)" Is it from that that you conclude "her practice was to leave her clock set to the time at the departure airport."? It seems to have been her practice on the South Atlantic crossing but on that flight - and, as far as we know, on all flights except the Lae/Howland flight - she didn't expect to keep any radio schedules. For the Lae/Howland flight she specifically said she would use Greenwich time.
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Thank you, Ric and Bob, for organizing and analyzing the mass of post-loss signal reports, and for publishing the results of your labors.
Perhaps you can answer some questions I have relating to reception probability in the catalog.
1. What transmitter powers were input to ICEPAC for operation at 3105 kHz and its harmonics?
2. What transmitter powers were input to ICEPAC for operation at 6210 kHz and its harmonics?
3. What values of ICEPAC “signal statistics” were used to calculate the probability of 0.0013 given in message 142 (Identifier 52130KK)? (These presumably would be the values for the input parameter, REQ. SNR, and the outputs, SNR and SNR UP.)
4. What values were used for the 0.00000067 probability, same message?
5. What SSN values were used for 3. and 4.?
Chuck
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Chuck:
1. and 2. The values are in my research paper "WE-13C Transmitter Harmonic Power Output" on the TIGHAR website.
3. REQ = 44 dB; SNR= -3 dB, SNRUP = 20.0 dB.
4. REQ = 44 dB; SNR = 7 dB, SNRUP = 9.8 dB.
5. SSN = 91.
Bob
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After reading the catalog of post-loss radio signals, it just baffles me how AE and FN could have been left for dead. There seems to have been ample evidence that they were broadcasting from somewhere. Could it have been a case of the civilians' experiences with what they thought were AE's messages not being communicated to the proper authorities in time to do something?
I try not to think about Amelia and Fred stranded on Niku after the Electra was taken by the sea, so very sad.
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1. and 2. The values are in my research paper "WE-13C Transmitter Harmonic Power Output" on the TIGHAR website.
3. REQ = 44 dB; SNR= -3 dB, SNRUP = 20.0 dB.
4. REQ = 44 dB; SNR = 7 dB, SNRUP = 9.8 dB.
5. SSN = 91.
Thanks, Bob.
1. and 2. The values are in my research paper "WE-13C Transmitter Harmonic Power Output" on the TIGHAR website.
I find that paper, and the powers given in it, to be way off the mark. I’ll begin to explain that by posting what I had in mind when I made my 11 July post (http://tighar.org/smf/index.php/topic,418.0.html) regarding the paper. (The post is here (http://tighar.org/smf/index.php/topic,418.msg6350.html#msg6350).)
3. REQ = 44 dB; SNR= -3 dB, SNRUP = 20.0 dB.
4. REQ = 44 dB; SNR = 7 dB, SNRUP = 9.8 dB.
I calculated 0.0013 for the data in (3.) and 0.00000065 for that in (4.), so I think I see how you’re doing the probabilities. I used Excel’s NORMSDIST( ) function for the standard normal cumulative distribution. What do you use?
I’ve examined the RELBIL and FNORML( ) functions that VOACAP uses for calculation of reliability, REL. FNORML( ) is a bit crude above a couple standard deviations, so the REL and probability results diverge for larger deviations, but it seems clear that your probability and VOACAP’s reliability (and ICEPAC’s) are calculated in the same way and represent the same thing.
The smallest non-zero reliability (probability) reported by ICEPAC and VOACAP is 0.01. Do you think there is a reason why the program authors chose not to cut it closer than that?
5. SSN = 91.
ICEPAC is intended for use with smoothed monthly (12-month running mean) sunspot numbers. The value you indicated, 91, was the daily sunspot number for 2 Jul 37 and 5 Jul 37. How do you justify using it?
Chuck
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Gus,
When I first read Betty's notebook, it had quite an impact on me. I had similar feelings when studying the catalog of post-loss messages, as it demonstrates Amelia's and Fred's persistent attempts to communicate with the outside world. I can only imagine the desperation behind each of those attempts.
LTM,
Cindy
TIGHAR #3167
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Folks,
Do we know who this gentleman was?
"A Kentucky man wrote to the London Daily Mirror in 1943 claiming he heard Earhart's distress signal on Aug. 10, 1937, by shortwave radio. According to the letter, which now is part of the 56-page FBI file, Earhart stated she was on an island northeast of the Marshalls."
http://findarticles.com/p/articles/mi_m1571/is_8_16/ai_60100203/pg_4/
I searched through the Post Loss catalog, finding only Nina Paxton from KY.
Thanks!
Best,
S
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Do we know who this gentleman was?
"A Kentucky man wrote to the London Daily Mirror in 1943 claiming he heard Earhart's distress signal on Aug. 10, 1937, by shortwave radio. According to the letter, which now is part of the 56-page FBI file, Earhart stated she was on an island northeast of the Marshalls."
http://findarticles.com/p/articles/mi_m1571/is_8_16/ai_60100203/pg_4/ (http://findarticles.com/p/articles/mi_m1571/is_8_16/ai_60100203/pg_4/)
Here is the 56-page FBI file. (http://tighar.org/wiki/FBI_file_on_Amelia_Mary_Earhart) Perhaps you can find the letter there and identify the man yourself.
Then you can look for "an island northeast of the Marshalls" on which AE and FN could land, survive for 5+ weeks, and suddenly transmit one distress message on 10 August, without being noticed by other occupants of the island then or since.
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Do we know who this gentleman was?
I strongly suspect that the "gentleman" was Nina Paxton. In 1943 Nina was writing to anyone who would listen and claiming that she had heard Earhart describe a location in the Marshalls. Nina is an interesting case. We've judged her initial report to the local newspaper as credible but her later embellished recollections were increasingly fanciful.
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Here are the entries in "Messages July 3, 1 – 47" (http://goo.gl/Pqm2x) where Gardner is listed as something other than -11:
Entry 2: Zulu 0010 July 3; Gardner 1310 July 3 [+13] (should be Gardner 1310 July 2?)
Entry 16: Zulu 0600 July 3; Gardner 1900 July 3 [+13] (should be Gardner 1900 July 2?)
Entry 22: Zulu 0608 July 3; Gardner 1908 July 3 [+13] (should be Gardner 1908 July 2?)
Entry 26: Zulu 0727 July 3; Gardner 1927 July 2 [-12] (should be Gardner 2027 July 2?)
Entry 31: Zulu 0835 July 3; Gardner 1935 July 2 [-13] (should be Gardner 2135 July 2?)
Entry 33: Zulu 0840 July 3; Gardner 2130 July 2 [-11:10] (should be Gardner 2140 July 2?)
Entry 38: Zulu 0916 July 3; Gardner 2116 July 2 [-12] (should be Gardner 2216 July 2?)
Entry 40: Zulu 0958 July 3; Gardner 2158 July 2 [-12] (should be Gardner 2258 July 2?)
Sheila your corrections are all correct except for Entry 16. July 3 is the correct date. The source is the Itasca radio log. They made the transmission at 1830 Itasca Time on July 3. That would be 0600Z and 1930 on Gardner all the same day.
The corrections have been made. Many thanks.
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Here are the entries in "Messages July 3, 1 – 47" (http://goo.gl/Pqm2x) where Gardner is listed as something other than -11:
Entry 2: Zulu 0010 July 3; Gardner 1310 July 3 [+13] (should be Gardner 1310 July 2?)
Entry 16: Zulu 0600 July 3; Gardner 1900 July 3 [+13] (should be Gardner 1900 July 2?)
Entry 22: Zulu 0608 July 3; Gardner 1908 July 3 [+13] (should be Gardner 1908 July 2?)
Entry 26: Zulu 0727 July 3; Gardner 1927 July 2 [-12] (should be Gardner 2027 July 2?)
Entry 31: Zulu 0835 July 3; Gardner 1935 July 2 [-13] (should be Gardner 2135 July 2?)
Entry 33: Zulu 0840 July 3; Gardner 2130 July 2 [-11:10] (should be Gardner 2140 July 2?)
Entry 38: Zulu 0916 July 3; Gardner 2116 July 2 [-12] (should be Gardner 2216 July 2?)
Entry 40: Zulu 0958 July 3; Gardner 2158 July 2 [-12] (should be Gardner 2258 July 2?)
Sheila your corrections are all correct except for Entry 16. July 3 is the correct date. The source is the Itasca radio log. They made the transmission at 1830 Itasca Time on July 3. That would be 0600Z and 1930 on Gardner all the same day.
The corrections have been made. Many thanks.
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1830 July 3rd, Itasca time plus 11.5 hours makes 0600 Z July 4th, minus 11 hours makes 1900 July 3rd Gardner time. (Using your conversion factors Gardner is always 1/2 hour ahead of Itasca time.)
gl
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1830 July 3rd, Itasca time plus 11.5 hours makes 0600 Z July 4th, minus 11 hours makes 1900 July 3rd Gardner time. (Using your conversion factors Gardner is always 1/2 hour ahead of Itasca time.)
My bad. The transmission was made at 1830 Itasca Time (Greenwich -11.5) on July 2, not July 3. Gardner time should be 1900 on the the 2nd, and Zulu should be 0600 on the 3rd. We'll fix it.
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I strongly suspect that the "gentleman" was Nina Paxton. In 1943 Nina was writing to anyone who would listen and claiming that she had heard Earhart describe a location in the Marshalls. Nina is an interesting case. We've judged her initial report to the local newspaper as credible but her later embellished recollections were increasingly fanciful.
Thanks, Ric - figured it was too much to hope that there was an uncoralled Post-Loss rambling around out there.
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Mainly for the exercise of it, but also because I like visuals, I put the Post-Loss reports into a spreadsheet showing left-right timeline for each day:
https://docs.google.com/spreadsheet/ccc?key=0Ano089QuiEhldEF4eUdGTDFRYmtubWZhOWRUQTRxQnc
Note that the entries are in order received; column one for July 2 isn't the same exact time as column one of July 3. But it does show the progression through each day. Just as in the Post-Loss catalog, all entries are included regardless of rating; the obvious next step would be to color code for that. I did use Post-Loss catalog's convention of light blue for transmissions to AE.
To create an even better visual, it would probably be good to use a consistent number of columns for each day (so that each column did in fact represent the same time block regardless of day), but it was already getting very wide.
Sorry if this is redundant - I do realize the longtimers here probably have multiple versions of such visual timelines. But since I worked it up, I might as well make it available for whoever finds it useful. It's unproofed as of tonight, although I've been fairly careful (famous last words).
Best,
Sheila
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Mainly for the exercise of it, but also because I like visuals, I put the Post-Loss reports into a spreadsheet showing left-right timeline for each day:
Sheila, I love it. You can already see the patterns emerging. Once you color-code the Credible, Not Credible, and Uncertain signals - hang on to your socks.
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Sheila, I love it. You can already see the patterns emerging. Once you color-code the Credible, Not Credible, and Uncertain signals - hang on to your socks.
Glad to hear it! There's something about seeing a visual cluster of reception reports that just drives it home for me.
Even though "not credibles" are included, I find that the truth (or a hint at it it) has a way of coming out; I think that even if one didn't realize some of the ham club members' reports were considered "not credible," one might look at their cluster of reports, all showing the same convenient times and at least have a "Hmm..." moment. One can never assume of course, but I remain very glad that the Post-Loss catalog includes all rx regardless of rating. The truth can come out in unexpected ways.
I hope this won't offend any here, but I once saw a New Testament which took an unorthodox color-coding approach--black for what the author felt strongly was wording which had been inserted by Roman officials for political reasons, brown for "uncertain," and red for what the author felt was most likely to be Jesus' actual words. Fascinating, and hard to ignore some of the patterns that emerged.
I host a folk music show so won't be able to color code tonight - trying to figure out a way, though, to sneak in the question on-air as to whether any of our listeners throughout Wisconsin have any stories in their family about a "relative who heard Amelia," lol. I don't see any Wisconsin rx in the data so far so not hoping for much.
QRX tonight,
Sheila
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But, using your sign convention, Gardner should be -12.
What do you mean by "sign convention?" Colorado, Swan, and Pelican all used -11 for the longitude of Gardner. That's what we used.
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The Navy regulation in force since 1920 ...That is what I meant by the different "sign conventions." Either method will work as long as you keep it straight and don't get confused.
The standard time zone that is 12 hours slow on Zulu time extends from longitude 172° 30' west longitude to the 180th meridian. Gardner is located at 174° 32' west longitude ...
We have seen that the Itasca, using the authority of the Navy regulation, set their clocks to a non-standard offset from Zulu, for their convenience, and did not maintain their clocks on the standard time zone in the vicinity of Howland which is 12 hours slow on Zulu, these other ships were doing the same thing.
gl
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BTW, in spite of everything you have read, there are actually 25 standard time zones not 24!
The zone descriptions run from +1 to + 12 (12 time zones); -1 to -12 (another 12 time zones); plus the zero time zone (GMT or Zulu time) for a total of 25 time zones. Using the military time zones designations, they run from "A" to "Z" (Alpha to Zulu) omitting only "J" (Juliette.) There are 26 letters in the alphabet, take away "J" and you are left with the same answer, 25 time zones.
gl
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I hope this won't offend any here, but I once saw a New Testament which took an unorthodox color-coding approach--black for what the author felt strongly was wording which had been inserted by Roman officials for political reasons, brown for "uncertain," and red for what the author felt was most likely to be Jesus' actual words. Fascinating, and hard to ignore some of the patterns that emerged.
You may be thinking of the Jesus Seminar. They produced a color-coded edition of the sayings attributed to Jesus in ancient texts (both canonical and non-canonical):
- red: That's Jesus!
- pink: Sure sounds like Jesus.
- gray: Well, maybe.
- black: There's been some mistake.
I recommend keeping words in your spreadsheet as well as using colors. You can sort on words (or numbers), but you can't sort on colors.
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looking at the spread sheet, is it possible over the 7 days each time the tide come in, it floated the electra in a 360 degree circle a bit at a time an thats why it was heard in diffrent places
sorry if this as already benn mention as i only looked at newest posts :)
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looking at the spread sheet, is it possible over the 7 days each time the tide come in, it floated the electra in a 360 degree circle a bit at a time an thats why it was heard in diffrent places
The tide was never high enough to float the airplane unless there was also big surf, in which case nobody is going to be going anywhere near the airplane.
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Time zones map for 2007
Many internet sites on time zones and the International Date Line still give incomplete or out-dated information, one of the very few that does give a correct depiction is www.worldtimezone.com (http://www.worldtimezone.com).
The link that Sheila gave in 2011 is not very accessible for the sight impaired.
I am told that a more accessible, WCAG 2.0 compatible version is www.thetimenow.com (http://www.thetimenow.com).
That is a purely text-based website.
Here is a large map from UNEC net (http://www.unec.net/) that may be more legible:
(http://www.unec.net/of_interest/WorldTimeZones/time_zones.jpg)
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Here is a large map from UNEC net (http://www.unec.net/) that may be more legible:
(http://www.unec.net/of_interest/WorldTimeZones/time_zones.jpg)
That map is a pretty good reference for current time zones but they have Kiribati wrong. Sine 2000, all of Kiribati is in a single time zone due to a huge jog inserted in the International Dateline.
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That map is a pretty good reference for current time zones but they have Kiribati wrong. Sine 2000, all of Kiribati is in a single time zone due to a huge jog inserted in the International Dateline.
Try, try again. From "World of Maps," (http://mapsof.net/) the likely source for the 1995 map above:
(http://mapsof.net/uploads/static-maps/standard_timezones_of_the_world.png)