Comments on: Understanding “satellite pings”… https://tmfassociates.com/blog/2014/03/15/understanding-satellite-pings/ Satellites, spectrum and other stuff Tue, 03 Feb 2026 21:36:32 +0000 hourly 1 http://wordpress.org/?v=3.3.1 By: Flight MH370 — search information in Google Earth – Adrod Sanm https://tmfassociates.com/blog/2014/03/15/understanding-satellite-pings/comment-page-2/#comment-86362 Flight MH370 — search information in Google Earth – Adrod Sanm Mon, 03 Oct 2016 07:13:50 +0000 http://tmfassociates.com/blog/?p=4895#comment-86362 [...] March 17, 17:45 UTC: As per this blog post on TMF associates, the interruption within the arc close to the Gulf of Thailand is as a result of Malaysian [...] [...] March 17, 17:45 UTC: As per this blog post on TMF associates, the interruption within the arc close to the Gulf of Thailand is as a result of Malaysian [...]

]]> By: The Locations of Inmarsat-3F1 when Pinging MH370 | Duncan Steel https://tmfassociates.com/blog/2014/03/15/understanding-satellite-pings/comment-page-2/#comment-44548 The Locations of Inmarsat-3F1 when Pinging MH370 | Duncan Steel Wed, 27 Aug 2014 19:10:33 +0000 http://tmfassociates.com/blog/?p=4895#comment-44548 [...] about one millisecond at the most. A blog to which I have been contributing (but see also this related blog) has rendered the information that the precision is ±300 microseconds (0.3 milliseconds). I am [...]

]]> By: MH370 Flight reconstruction (Part 7) | The MH370 Skeptic https://tmfassociates.com/blog/2014/03/15/understanding-satellite-pings/comment-page-2/#comment-31146 MH370 Flight reconstruction (Part 7) | The MH370 Skeptic Sun, 25 May 2014 03:52:13 +0000 http://tmfassociates.com/blog/?p=4895#comment-31146 [...] Understanding “satellite pings???… (–click here for link) [...]

]]> By: SyGunson https://tmfassociates.com/blog/2014/03/15/understanding-satellite-pings/comment-page-2/#comment-29183 SyGunson Thu, 15 May 2014 00:26:31 +0000 http://tmfassociates.com/blog/?p=4895#comment-29183 Malaysia published a map with a track for MH370 on 1st May which portrays the aircraft turning south off Aceh province, Sumatra at 18:25 UTC then flying towards the satellite to a point west of Sumatra at 19:41 UTC. Yet the Burst Offset Frequency chart shows the opposite between 18:25 and 19:41 UTC, that the frequency is reducing rapidly as if MH370 were flying away. These two conditions are mutually irreconcilable therefore MH370 could not have flown through the Straits of Malacca as stated. Malaysia published a map with a track for MH370 on 1st May which portrays the aircraft turning south off Aceh province, Sumatra at 18:25 UTC then flying towards the satellite to a point west of Sumatra at 19:41 UTC.

Yet the Burst Offset Frequency chart shows the opposite between 18:25 and 19:41 UTC, that the frequency is reducing rapidly as if MH370 were flying away.

These two conditions are mutually irreconcilable therefore MH370 could not have flown through the Straits of Malacca as stated.

]]> By: Links to Previous Posts on the Inmarsat-3F1/MH370 Ping Analysis Saga | Duncan Steel https://tmfassociates.com/blog/2014/03/15/understanding-satellite-pings/comment-page-2/#comment-22795 Links to Previous Posts on the Inmarsat-3F1/MH370 Ping Analysis Saga | Duncan Steel Fri, 04 Apr 2014 11:17:27 +0000 http://tmfassociates.com/blog/?p=4895#comment-22795 [...] Understanding “satellite pings??? … [...]

]]> By: blacksabre https://tmfassociates.com/blog/2014/03/15/understanding-satellite-pings/comment-page-2/#comment-21719 blacksabre Sun, 30 Mar 2014 16:59:59 +0000 http://tmfassociates.com/blog/?p=4895#comment-21719 Whilst on hijack possibilities, what if the plane did go to Mauritius, with the satellite above the equator is it possible or what makes the pings sound or look different travelling East/West as opposed to North/South? Is it possible that they could have used a decoy plane or drone to emit a false signal? Whilst on hijack possibilities, what if the plane did go to Mauritius, with the satellite above the equator is it possible or what makes the pings sound or look different travelling East/West as opposed to North/South?

Is it possible that they could have used a decoy plane or drone to emit a false signal?

]]> By: blacksabre https://tmfassociates.com/blog/2014/03/15/understanding-satellite-pings/comment-page-2/#comment-21694 blacksabre Sun, 30 Mar 2014 15:11:39 +0000 http://tmfassociates.com/blog/?p=4895#comment-21694 Thanks Tim for your explanations. Could you or someone else please explain why Inmarsat are so sure MH370 flew South and not North? I understand the ping in relation to distance with the Doppler effect but I have not been able to find any explanation as to how they determined direction of travel just that they based their opinion on analyzing 6 or so other 777's in the area at the time but they fail to say what exact information they gained from them. My concern is they have not explained how this was arrived at and whether it is 100% without question correct and not 99% as that is leaving a doubt. I wonder why the Northern path was ruled out so quickly. As I understand they can shadow or fly very low to avoid radar detection. We know the flight was sabotaged but not by whom, a lot of effort to conceal the plane took place as well as changing routes etc It just poses the question if on a presumed suicide mission would he/they not have just flown it straight into the ocean or land straight after take off. I believe there is a very good chance it went North to the middle east area. Valuable plane and perhaps valuable cargo. Thanks Tim for your explanations. Could you or someone else please explain why Inmarsat are so sure MH370 flew South and not North? I understand the ping in relation to distance with the Doppler effect but I have not been able to find any explanation as to how they determined direction of travel just that they based their opinion on analyzing 6 or so other 777′s in the area at the time but they fail to say what exact information they gained from them. My concern is they have not explained how this was arrived at and whether it is 100% without question correct and not 99% as that is leaving a doubt. I wonder why the Northern path was ruled out so quickly. As I understand they can shadow or fly very low to avoid radar detection. We know the flight was sabotaged but not by whom, a lot of effort to conceal the plane took place as well as changing routes etc It just poses the question if on a presumed suicide mission would he/they not have just flown it straight into the ocean or land straight after take off. I believe there is a very good chance it went North to the middle east area. Valuable plane and perhaps valuable cargo.

]]> By: What if they are wrong? Satellite Company Inmarsat reversed position on where MH370 plane flight may be - Celebzter.com https://tmfassociates.com/blog/2014/03/15/understanding-satellite-pings/comment-page-2/#comment-21263 What if they are wrong? Satellite Company Inmarsat reversed position on where MH370 plane flight may be - Celebzter.com Fri, 28 Mar 2014 15:23:18 +0000 http://tmfassociates.com/blog/?p=4895#comment-21263 [...] stumbled upon a bunch of experts in satellite and mobile consulting  like  Palo Alto USA based TMF Associates and others  on the ‘net. Chatting it up in forums were other engineers, physicists, former [...]

]]> By: seanhelmi https://tmfassociates.com/blog/2014/03/15/understanding-satellite-pings/comment-page-2/#comment-21081 seanhelmi Thu, 27 Mar 2014 20:55:30 +0000 http://tmfassociates.com/blog/?p=4895#comment-21081 I still do not understand how the distance can be determined from time period. I do infer from one of timfarrar's replies above, that scheduled very precise timeslots are involved. So if the plane is scheduled to transmit precisely on the hour, then the time delay between 1am, 2am GMT (precise) and receipt of the signal by the satellite would permit calculation of the distance. But doesn't this require either a very precise clock onboard the plane or synchronization of the satellite clock with the plane clock, which requires periodic or continuous transmission. I understand GPS works because the satellites all have synchronized atomic clocks on board and the signal from the satellite includes timestamp information. The GPS device (e.g. mobile phone) does not have an accurate clock but can derive the time duration of transmission by comparing timestamp information from multiple satellites, all of which send the transmission at precisely the same time. But here there was only one satellite, and the airplane did not process the data let alone return any content to the satellite. I understand the handshake process begins with a transmission from the satellite to the aircraft. Does each satellite transmission include a "timeslot" for the return transmission? For example the satellite transmits a signal to the plane at 1am that states, reply at 1:01am. That would still require synchronized clocks. Or does the satellite transmission state, say, send a return signal exactly 1 minute from receipt of this transmission? That last would only require a timepiece onboard the plane that can accurately time a 1 minute interval. Assuming (not a big assumption here?) that the plane equipment was functioning, the time delay between the scheduled transmission time and the receipt by the satellite can be used to determine distance. Is this correct? Please excuse my query. I have no expertise in this area and am trying to find out how this works. I still do not understand how the distance can be determined from time period. I do infer from one of timfarrar’s replies above, that scheduled very precise timeslots are involved. So if the plane is scheduled to transmit precisely on the hour, then the time delay between 1am, 2am GMT (precise) and receipt of the signal by the satellite would permit calculation of the distance. But doesn’t this require either a very precise clock onboard the plane or synchronization of the satellite clock with the plane clock, which requires periodic or continuous transmission. I understand GPS works because the satellites all have synchronized atomic clocks on board and the signal from the satellite includes timestamp information. The GPS device (e.g. mobile phone) does not have an accurate clock but can derive the time duration of transmission by comparing timestamp information from multiple satellites, all of which send the transmission at precisely the same time. But here there was only one satellite, and the airplane did not process the data let alone return any content to the satellite.
I understand the handshake process begins with a transmission from the satellite to the aircraft. Does each satellite transmission include a “timeslot” for the return transmission? For example the satellite transmits a signal to the plane at 1am that states, reply at 1:01am. That would still require synchronized clocks. Or does the satellite transmission state, say, send a return signal exactly 1 minute from receipt of this transmission? That last would only require a timepiece onboard the plane that can accurately time a 1 minute interval. Assuming (not a big assumption here?) that the plane equipment was functioning, the time delay between the scheduled transmission time and the receipt by the satellite can be used to determine distance. Is this correct?
Please excuse my query. I have no expertise in this area and am trying to find out how this works.

]]> By: airlandseaman https://tmfassociates.com/blog/2014/03/15/understanding-satellite-pings/comment-page-2/#comment-20672 airlandseaman Wed, 26 Mar 2014 13:02:22 +0000 http://tmfassociates.com/blog/?p=4895#comment-20672 It occurs to me that the IOR Inmarsat S/C, with a significant inclination, could provide the means to solve for a crude absolute path, not just hemisphere ambiguous LOPs and Doppler. If one used a single "Grand Solution" for all the equations of motion, for all 12 observation sets, in a LSF/Kalman filter type solution, you get math not unlike what is used for older LEO navigation satellites like Transit. IOW...A single moving satellite is essentially like having 12 quasi independent satellites from which we can triangulate. Oversimplified, but it helps to visualize what is going on. Of course, the geometric dilution associated with a geo s/c moving a few degrees is much greater than what you get with a 15 minute Transit pass, but potentially informative. Note that this is apparently the information used by Inmarsat to conclude the aircraft went south, not north. But there may be more that can be squeezed out. It occurs to me that the IOR Inmarsat S/C, with a significant inclination, could provide the means to solve for a crude absolute path, not just hemisphere ambiguous LOPs and Doppler. If one used a single “Grand Solution” for all the equations of motion, for all 12 observation sets, in a LSF/Kalman filter type solution, you get math not unlike what is used for older LEO navigation satellites like Transit. IOW…A single moving satellite is essentially like having 12 quasi independent satellites from which we can triangulate. Oversimplified, but it helps to visualize what is going on. Of course, the geometric dilution associated with a geo s/c moving a few degrees is much greater than what you get with a 15 minute Transit pass, but potentially informative. Note that this is apparently the information used by Inmarsat to conclude the aircraft went south, not north. But there may be more that can be squeezed out.

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