1. 根据Inmarsat卫星公司提供给英国空难调查部门(AAIB)的关于马航失踪班机MH370的实测卫星通讯信号频移数据如下:
2. 新西兰的Duncan Steel 和 Mike Exner 对上述实测的综合频移数据值进行了初始校正和频率成分的分解效验,最终提取出合理有效的频移数据值如下。细节请参照Duncan 网站的解释, http://www.duncansteel.com/archives/526
3. Duncan 和 Mike 还进一步根据校正后的频移数据计算出飞机在相应时刻相对于卫星地表投影点的视速度,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. 现在,我们根据上面的相对于卫星的飞机视速度数据,结合飞机的平均飞行速度可计算出飞机在相应时间点的相对于卫星方向的偏角,即可计算出飞机飞行的方向。另外,我们还能算出而知时间点间的飞行距离。二者结合,可很好的确定飞机的位置。
计算过程和结果:
###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]
时间--time "18:29" "19:40" "20:40" "21:40" "22:40" "00:11"
视速度-line_of_sight_speed "39.77" "39.14" "60.8" "79.85" "100.64" "125.35"
飞速432节的偏角--angle_by432knots "71.5" "71.6" "68.5" "65.8" "62.7" "58.9"
飞速432节距离distance_in_between_by432knots "0" "944" "798" "798" "798" "1210"
飞速463节偏角angle_by463knots "72.8" "72.9" "70.1" "67.5" "64.7" "61.3"
飞速463节距离distance_in_between_by463knots "0" "1015" "858" "858" "858" "1301"
>
5. 马航失踪航班的航迹和终点位置。
(请看续篇)