1. 根據Inmarsat衛星公司提供給英國空難調查部門(AAIB)的關於馬航失蹤班機MH370的實測衛星通訊信號頻移數據如下:
2. 新西蘭的Duncan Steel 和 Mike Exner 對上述實測的綜合頻移數據值進行了初始校正和頻率成分的分解效驗,最終提取出合理有效的頻移數據值如下。細節請參照Duncan 網站的解釋, http://www.duncansteel.com/archives/526
3. Duncan 和 Mike 還進一步根據校正後的頻移數據計算出飛機在相應時刻相對於衛星地表投影點的視速度,如下表。
Time (UTC) Line-of-Sight Speed (knots)
18:29/2:39 39.77
19:40/3:50 39.14
20:40/4:50 60.80
21:40/5:50 79.85
22:40/6:50 100.64
00:11/8:19 125.35
4. 現在,我們根據上麵的相對於衛星的飛機視速度數據,結合飛機的平均飛行速度可計算出飛機在相應時間點的相對於衛星方向的偏角,即可計算出飛機飛行的方向。另外,我們還能算出而知時間點間的飛行距離。二者結合,可很好的確定飛機的位置。
計算過程和結果:
###Parameters
> pi
##speed unit all by knots
> line_of_sight_speed
> satelite_speed
###Calculate the angle bias from the satellite direction by average 463 knots flight speed
> flight_speed
> cos_angle_by_pi
> angle_by_pi
> angle_432
> angle_432
[1] 71.51477 71.60285 68.54682 65.80534 62.74426 58.99171
###Calculate the angle bias from the satellite direction by average 463 knots flight speed
> flight_speed
> cos_angle_by_pi
> angle_by_pi
> angle_463
> angle_463
[1] 72.79259 72.87419 70.04679 67.51774 64.70365 61.27086
###Summary
> summary_table
事件--event [,1] [,2] [,3] [,4] [,5] [,6]
時間--time "18:29" "19:40" "20:40" "21:40" "22:40" "00:11"
視速度-line_of_sight_speed "39.77" "39.14" "60.8" "79.85" "100.64" "125.35"
飛速432節的偏角--angle_by432knots "71.5" "71.6" "68.5" "65.8" "62.7" "58.9"
飛速432節距離distance_in_between_by432knots "0" "944" "798" "798" "798" "1210"
飛速463節偏角angle_by463knots "72.8" "72.9" "70.1" "67.5" "64.7" "61.3"
飛速463節距離distance_in_between_by463knots "0" "1015" "858" "858" "858" "1301"
>
5. 馬航失蹤航班的航跡和終點位置。
(請看續篇)