方位角，仰角，范围和观测者纬度，经度，经度的ECEF [英] ECEF from Azimuth, Elevation, Range and Observer Lat,Lon,Alt
问题描述
我正在尝试编写一个基本的python脚本，该脚本将从给定位置跟踪由tle定义的给定卫星.我不是一个惯性/轨道的人，但是正在努力变得更聪明.
I'm trying to write a basic python script that will track a given satellite, defined with tle's, from a given location. I'm not a asto/orbital person but am trying to become smarter on it.
当我尝试将方位角，仰角，范围值转换为ECEF位置时遇到问题.我正在使用PyEphem来获取观测值，并使用spg4来获取要验证的真实位置.我也在使用网站 http://www.n2yo.com/?s=25544 ，验证值.
I am running into a problem when I try to convert the azimuth, elevation, range values to a ECEF position. I'm using PyEphem to get the observation values and spg4 to get the real location to verify. I'm also using the website, http://www.n2yo.com/?s=25544, the verify the values.
我得到的观察到的方位角，仰角和范围如下:
I'm getting the observed azimuth, elevation and range with:
def get_ob(epoch, sv, obsLoc):
site = ephem.Observer()
site.lon = str(obsLoc.lat) # +E -104.77 here
site.lat = str(obsLoc.lon) # +N 38.95 here
site.elevation = obsLoc.alt # meters 0 here
#epoch = time.time()
site.date = datetime.datetime.utcfromtimestamp(epoch)
sat = ephem.readtle(sv.name,sv.tle1,sv.tle2)
sat.compute(site)
az = degrees(sat.az)
el = degrees(sat.alt)
#range in m
range = sat.range
sat_lat = degrees(sat.sublat)
sat_long = degrees(sat.sublong)
# elevation of sat in m
sat_elev = sat.elevation
x, y, z = aer2ecef(az,el,range,38.95,-104.77,80 / 1000)
所报告的方位角，仰角和范围与网站匹配.我要通过以下方式转换为ECEF职位:
The reported azimuth, elevation and range match the website. I'm converting to ECEF positions with:
def aer2ecef(azimuthDeg, elevationDeg, slantRange, obs_lat, obs_long, obs_alt):
#site ecef in meters
sitex, sitey, sitez = llh2ecef(obs_lat,obs_long,obs_alt)
#some needed calculations
slat = sin(radians(obs_lat))
slon = sin(radians(obs_long))
clat = cos(radians(obs_lat))
clon = cos(radians(obs_long))
azRad = radians(azimuthDeg)
elRad = radians(elevationDeg)
# az,el,range to sez convertion
south = -slantRange * cos(elRad) * cos(azRad)
east = slantRange * cos(elRad) * sin(azRad)
zenith = slantRange * sin(elRad)
x = ( slat * clon * south) + (-slon * east) + (clat * clon * zenith) + sitex
y = ( slat * slon * south) + ( clon * east) + (clat * slon * zenith) + sitey
z = (-clat * south) + ( slat * zenith) + sitez
return x, y, z
但是，当我绘制该图时，该位置偏离了(地球的反面).我从网站和spg4获得的排名匹配，因此我认为这些是正确的.
When I plot that though, the position is way off (wrong side of globe). The position I get from the website and from spg4 match so I believe those to be the correct.
我不确定该错误是否出在我的转换方法中，还是我使用了错误的数据进行转换.我在以下答案中找到了该方法:获取ECEF XYZ给定起始坐标，范围，方位角和海拔高度
I'm not sure if the error is in my conversion method or I'm using the wrong data for the conversion. I found the method in a answer here: Get ECEF XYZ given starting coordinates, range, azimuth, and elevation
对于我要去哪里的任何建议或建议，我们将不胜感激.以下是测试输入/输出:
Any advice or suggestions for where I'm getting off would be very appreciated. Below is test input/outputs:
我正在测试的卫星是ISS和directv10(一颗固定的一颗正在移动，可通过互联网跟踪进行验证)
The satellites I'm testing with are the ISS and directv10 (one fixed, one moving- with internet tracking available for verification):
0 Direct10
1 31862U 07032A 13099.15996183 -.00000126 00000-0 10000-3 0 1194
2 31862 000.0489 046.9646 0000388 001.7833 103.5813 01.00271667 21104
0 ISS
1 25544U 98067A 13112.50724749 .00016717 00000-0 10270-3 0 9148
2 25544 51.6465 24.5919 0009906 171.1474 188.9854 15.52429950 26067
观察者站点lla:
[38.95 -104.77 0.0]
结果:
sv: ISS ephem observed response(km) @ epoch: 1365630559.000000 : [344.067992722211, -72.38297754053431, 12587.123][degrees(sat.az), degrees(sat.alt), sat.range]
sv: ISS ephem reported llh location(km) @ epoch: 1365630559.000000 : [-41.678271938092195, -129.16682754513502, 421.06290625][degrees(sat.sublat0, degrees(sat.sublong), sat.elevation]
sv: ISS ephem calculated xyz location(km) @ epoch: 1365630559.000000 : [688.24385373837845, 6712.2004971137103, -704.83633267710866][aer2ecef(az,el,range,obsLoc.lat,obsLoc.lon,obsLoc.alt)]
sv: ISS ephem llh from calc xyz location(km) @ epoch: 1365630559.000000 : [-6.001014287867631, 84.1455657632957, 12587.123][ecef2llh()]
sv: ISS ephem xyz from reported llh location(km) @ epoch: 1365630559.000000 :[-3211.7910504146325, -3942.7032969856118, -4498.9656030253745][llh2ecef(lat,long,elev)]
sv: ISS spg84 ecef position(m) @ epoch: 1365630559.000000 : [-3207667.3380003194, -3936704.823960199, -4521293.5388663234]
sv: ISS spg84 ecef2llh(m) @ epoch: 1365630559.000000 : [-41.68067424524357, -129.17349987675482, 6792812.8704163525]
sv: Direct10 ephem observed response(km) @ epoch: 1365630559.000000 : [320.8276456938389, -19.703680198781303, 43887.572][degrees(sat.az), degrees(sat.alt), sat.range]
sv: Direct10 ephem reported llh location(km) @ epoch: 1365630559.000000 : [0.004647324660923812, -102.8070784813048, 35784.688][degrees(sat.sublat0, degrees(sat.sublong), sat.elevation]
sv: Direct10 ephem calculated xyz location(km) @ epoch: 1365630559.000000 : [-18435.237655222769, 32449.238763035213, 19596.893001978762][aer2ecef(az,el,range,obsLoc.lat,obsLoc.lon,obsLoc.alt)]
sv: Direct10 ephem llh from calc xyz location(km) @ epoch: 1365630559.000000 : [27.727834453026748, 119.60200825103102, 43887.572][ecef2llh()]
sv: Direct10 ephem xyz from reported llh location(km) @ epoch: 1365630559.000000 :[-9346.1899009219123, -41113.897098582587, 3.4164105611003754][llh2ecef(lat,long,elev)]
sv: Direct10 spg84 ecef position(m) @ epoch: 1365630559.000000 : [-9348605.9260040354, -41113193.982686974, -14060.29781505302]
sv: Direct10 spg84 ecef2llh(m) @ epoch: 1365630559.000000 : [-0.019106864351793953, -102.81049179145006, 42156299.077687651]
推荐答案
我真的很傻，但是发现了问题...
I feel really dumb but found the issue...
我正在将站点的纬度和经度转换为PyEphem模型(请参阅第3-4行)...转换当前有效.
I was transposing the the latitude and longitude from the site into the PyEphem model (look at line 3-4)...The conversion works currently.
让孩子们上一堂课.使用好的变量名...不要像我这样懒惰，不要浪费时间去寻找一个不存在的数学错误....
Let that be a lesson kids. USE GOOD VARIABLE NAMES...don't be lazy like me and lose time trying to find a nonexistent math bug....
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