Originally Posted by
wiedehopf
Aircraft transmit vertical speed.
Also looking at the data points in question deriving it from altitude and time would not have yielded that rate.
2018-10-28 23:31:51Z.024 0x8a0711 LNI610 -5.82061 107.12238 2500 1742 382 34 -16896
2018-10-28 23:31:54Z.392 0x8a0711 LNI610 -5.8161 107.12541 1450 1742 383 34 -26560
2018-10-28 23:31:56Z.030 0x8a0711 LNI610 -5.81346 107.12698 425 1742 360 33 -30976
Actually, it seems that the descent rate derived from altitude and time matches the reported vertical speed fairly well. Take a look at the two intervals above. In the first interval the airplane descends from 2500 msl to 1450 msl in 3 seconds. 1050 ft/3 seconds equates to 21,000 fpm. the reported vertical speeds are 16,896 fpm at the beginning of the interval and 26,560 fpm at the end. In the second interval the airplane descends from 1450 MSL to 425 MSL in 2 seconds. 1024 ft in 2 seconds equates to a 30,720 fpm. reported vertical speed at the end of the second interval 30,976 fpm. Not a perfect match, but not off by a large amount.
Maybe I'm not following what you mean by: "would not have yielded that rate"