3 ms·

Because who is looking in the middle of the Indian Ocean at commercial airliners. There’s far more important targets and areas for these systems to focus on

by stirlo 3y ago

H8crilA 3y ago
Yes indeed. You can see for example here what kind of lead times are we talking about: https://sar.iceye.com/5.0/productguide/ordering/ https://sar.iceye.com/5.0/productguide/ordering/ Any serious military is tracking all known imaging/SAR satellites and uses their fly-by times (which are entirely predictable) for moving stuff covertly. I.e. you want to be out in the open in Area 51 testing a new RQ-180 derivative only when no one can be looking at you right now. Also, there are global ADS-B satellite relays, and frankly I don't know why this data wasn't logged for MH370 - it must be explained somewhere. There's a guy on Twitter who captures those on a custom antenna + BladeRF setups (this data is plugged into adsbexchange for oceanic routes coverage). AIS relies even more on satellite relays, as the curvature of the planet limits signal propagation much more than for airplanes. What you see on any AIS website is mostly from a satellite.
- lazide 3y ago
  Someone disabled the transponder before they turned off into the ocean is why.
- BenjiWiebe 3y ago
  Apparently the ADS-B transponder on MH370 was received but stopped suddenly.
- defrost 3y ago
  Interestingly there are 7 hours of logged Inmarsat Classic Aero mobile handshake data from (IIRC) the "smart engine" telemetry. The logged transmission round trip GroundStation -> Sat -> Aircraft -> Sat -> GroundStation provided an non unique "arc of travel" across the globe that was used by Australia to narrow the search area to a truckload of ocean floor that was substantially smaller than the entire planet. The archived versions of the logs saved by the Malaysian gov are: https://web.archive.org/web/20160304040818/http://www.dca.gov.my/mainpage/MH370%20Data%20Communication%20Logs.pdf https://web.archive.org/web/20160304040818/http://www.dca.go... Alternating sat routing would have given a more definitive fix and removed the ambiguity.
  - hammock 3y ago
    Many have lost trust in the WSPR data and Inmarsat pings. (Example: https://twitter.com/JustXAshton/status/1699535126663688544 https://twitter.com/JustXAshton/status/1699535126663688544) Your source conveniently omits weird data in the logs that start at 18:39:55UTC (a bunch of zeros, like something errored out). Satellite pings switch to IOR at 15:59UTC and never change back to POR despite the plane flying east towards it. Going east until 17:21 UTC the plane should have pinged POR but doesn't
    - defrost 3y ago
      That's the archive.org mirror of the openly declared edited from raw logs version released by Malaysia .. so not "my source" which, back in the day, were the raw logs from ground stations. The specific issue I have with hyper focused attention on these specific logs and hoorah about "weird data" is that I haven't seen much in the way of properly comparative analysis of a super set of broad fleet Inmarsat logs ... these in general are the trailing edge of quality data, riddled with nuls, semi handshakes, line noise, etc. Transponders are for positioning, black boxes for logging important flight data, diagnostic interfaces for mechanics in hangers ... and component level Inmarsat .. pretty much not more than a curiousity of "because we can" that's occasionally useful when a properly formed messages truly indicates an inflight issue. Ping routing and ping times were never meant to be consistent nor used for gross "half-LORAN" positioning .. this is all happenstance after event signal engineering hack work.

Because who is looking in the middle of the Indian Ocean at commercial airliners. There’s far more important targets and areas for these systems to focus on

by stirlo 3y ago

Because who is looking in the middle of the Indian Ocean at commercial airliners. There’s far more important targets and areas for these systems to focus on

H8crilA 3y ago

Yes indeed. You can see for example here what kind of lead times are we talking about: https://sar.iceye.com/5.0/productguide/ordering/ https://sar.iceye.com/5.0/productguide/ordering/ Any serious military is tracking all known imaging/SAR satellites and uses their fly-by times (which are entirely predictable) for moving stuff covertly. I.e. you want to be out in the open in Area 51 testing a new RQ-180 derivative only when no one can be looking at you right now. Also, there are global ADS-B satellite relays, and frankly I don't know why this data wasn't logged for MH370 - it must be explained somewhere. There's a guy on Twitter who captures those on a custom antenna + BladeRF setups (this data is plugged into adsbexchange for oceanic routes coverage). AIS relies even more on satellite relays, as the curvature of the planet limits signal propagation much more than for airplanes. What you see on any AIS website is mostly from a satellite.

lazide 3y ago
Someone disabled the transponder before they turned off into the ocean is why.
BenjiWiebe 3y ago
Apparently the ADS-B transponder on MH370 was received but stopped suddenly.
defrost 3y ago
Interestingly there are 7 hours of logged Inmarsat Classic Aero mobile handshake data from (IIRC) the "smart engine" telemetry. The logged transmission round trip GroundStation -> Sat -> Aircraft -> Sat -> GroundStation provided an non unique "arc of travel" across the globe that was used by Australia to narrow the search area to a truckload of ocean floor that was substantially smaller than the entire planet. The archived versions of the logs saved by the Malaysian gov are: https://web.archive.org/web/20160304040818/http://www.dca.gov.my/mainpage/MH370%20Data%20Communication%20Logs.pdf https://web.archive.org/web/20160304040818/http://www.dca.go... Alternating sat routing would have given a more definitive fix and removed the ambiguity.
- hammock 3y ago
  Many have lost trust in the WSPR data and Inmarsat pings. (Example: https://twitter.com/JustXAshton/status/1699535126663688544 https://twitter.com/JustXAshton/status/1699535126663688544) Your source conveniently omits weird data in the logs that start at 18:39:55UTC (a bunch of zeros, like something errored out). Satellite pings switch to IOR at 15:59UTC and never change back to POR despite the plane flying east towards it. Going east until 17:21 UTC the plane should have pinged POR but doesn't
  - defrost 3y ago
    That's the archive.org mirror of the openly declared edited from raw logs version released by Malaysia .. so not "my source" which, back in the day, were the raw logs from ground stations. The specific issue I have with hyper focused attention on these specific logs and hoorah about "weird data" is that I haven't seen much in the way of properly comparative analysis of a super set of broad fleet Inmarsat logs ... these in general are the trailing edge of quality data, riddled with nuls, semi handshakes, line noise, etc. Transponders are for positioning, black boxes for logging important flight data, diagnostic interfaces for mechanics in hangers ... and component level Inmarsat .. pretty much not more than a curiousity of "because we can" that's occasionally useful when a properly formed messages truly indicates an inflight issue. Ping routing and ping times were never meant to be consistent nor used for gross "half-LORAN" positioning .. this is all happenstance after event signal engineering hack work.