"Geocaching" in the Ionosphere

"Geocaching" in the ionosphere – The Search for MH370 by the amateur radio community Malaysian Flight MH370, a modern airliner B777, disappeared seven years ago on 2014.03.08 seemingly without a trace. Experts from various fields (i.e. Inmarsat) did not prevail til today. Maybe ham radio can contribute by using stored WSPR data from the database www.wsprnet.org. The data for that night's tragedy as well as the SAR operations exist in addition to many air accidents (AF447, MH17,...). The doomed flight happened close to the peak of solar cycle 24. In 2021 we have detected several aircraft in Antarctica such as a B787-9, two Dassault Falcon 900EX, an Iljuschin IL-76TD and a DC3C commuter airplane by conducting WSPR tests between DP0GVN as TX and ZL2005SWL as RX. Reference location data were used from Flightradar24. WSPR stations in Antartica were DP0GVN and the exploration ship Polarstern DP0POL/mm. QFA2904 flights to Anatarctica heading 180 degrees and retour were used to study backscatter effects from Perth (VK6) to Japan (JH3APN). Additional tests have been done in 2020 with repatriation flight QFA114 between JNB and PER over the Southern Indian Ocean (SIO). Other WSPR testing between ZS and KH6 and daily flights SIA478 and 479 have been conducted by monitoring WSPR data on www.wsprnet.org (secondary data) and www.kiwisdr.com (570 receivers worldwide with raw or primary data). Data have been gathered for the whole flight duration of app. 8 hours with signals from 7 MHz to 28 MHz and stations from Europe, Asia, North and South America as well as Australia and New Zealand. WSPR signals indicate the U-turn at 17:22 h UTC. Especially the "end game" offers a lot of data for Grayline, night and day reception, possible 28 MHz backscatter, short path (SP) as well as long path (LP) propagation. Trajectories have been studied by means of VOACAP etc. In depth cooperation between radio amateurs and science is encouraged with regard to interpretation of the received HF signals with emphasis on ionospheric behaviour and anomalies at mid-latitude (app. -30 degrees, -90 degrees) in the Southern hemisphere. WSPR data could eventually support the Inmarsat data and debris drift data by means of data fusion. They could also provide evidence if the wreckage is in the SIO or close to the Christmas Islands (VK9) as another theory based on research with hydrophones suggests.