Originally Posted by
Robin Clark
Although the timing of the last few pings does support a relatively straight line flight , surely it is not the only solution ...????....... The last four complete pings only really show that the source was south of the equator , and in an hour moved about 186 nm further Eastward/further from the satellite's longitude. , then another 240 some nm East during the next hour , and then about 266 nm in the following hour . This could mean a crippled aircraft was flying slowly SSE but turning gently left to end up flying East ........putting it in the sea somewhere between the equator and 10 degrees South latitude.....??....
My understanding of the INMARSAT information is that it is
both timing
and doppler shift. The timng gives the range ring, the doppler shift an indication of the relative velocities of the aircraft and satellite during that ping. The velocity of the satellite is known so the velocity of the aircraft across the range ring can be calculated. Thus for any likely speed two tracks for the aircraft can be calculated for each ping. Then the probabilities come in plus the airborne time vs endurance at varoius speeds and levels. I would think by logical steps the possible aircraft htrack, speed, and level can be estimated reasonably accurately.