NAME:
sat0intro - Intro to using the ao satellite prediction routines.
The ao idl satxxx routines will predict passes of satellites over AO.
They interface to the predict program:
PREDICT: A satellite tracking/orbital prediction program
Project started 26-May-1991 by John A. Magliacane, KD2BD
Last update: 14-May-2006
The routines use two line element sets (tle's) that are updated daily
at the observatory. They can only be run at AO since they are calling
the predict program which is not distributed with phil's idl routines.
Getting started:
@phil
@satinit
satpassplt,/gps
.. will plot the gps constellation passes for the current time.
the routines currently available can be found via:
explain,satdoc
.. it outputs:
satdoc - routine list (single line)
normal routines called by user
satdoc - routine list (single line)
1.satinfo - return tle entry for all satellites
2.satpass - compute satellite pass at AO
3.satpassconst - compute satellite pass for a constellation
4.satpassplt - plot all sat of constellation as they pass over AO
utility routines used by above routines (and be user if they want)
satfindtle - find tle file for satellite name
satsetup - return setup info for sat routines
satinptlefile - input an entire tle file
satlisttlefiles - return list of tle files
*************************************************************
1. satinfo - to find out which satellites we have tle files for:
*************************************************************
return a structure holding info on all satellites we know about:
n=satinfo(satI)
help,satI,/st
NM STRING 'GIOVE-A'
TLEFILE STRING '/share/megs/phil/predict/tle/galileo.tle'
TLE STRUCT -> Array[1]
.. The tle info for each satellite
help,satI.tle,/st
SATNM STRING 'GIOVE-A'
SATNUM INT 28922
SATCLASS STRING 'U'
LAUNCHYR LONG 2005
LAUNCHNUM INT 51
LAUNCHPIECE STRING 'A '
EPOCHYR LONG 2008
EPOCHDAY DOUBLE 260.32344
TMDER1 DOUBLE 2.2000000e-07
TMDER2 STRING ' 00000-0'
DRAG DOUBLE 10000.000
EPHTYPE STRING '0'
ELMNUM INT 394
INCLINATION DOUBLE 56.055200
RAASCNODE DOUBLE 164.58550
ECCENTRICITY STRING '0007843'
ARGOFPERIGEE DOUBLE 331.59930
MEANANOMALY DOUBLE 28.417500
MEANMOTION DOUBLE 1.7019477
REVNUM LONG 1690
LINES STRING Array[3]
************************************************************
2. satpass - Compute a single pass for a 1 satellite:
************************************************************
npts=satpass(satNm,passI,hhmmss=hhmmss,yymmdd=yymmdd)
Returns and array passI[npts] that holds info for each point of the
pass.
help,passI
JD DOUBLE 2.7793265e+08 .. jd for this point
SECS DOUBLE 1.2221659e+09 .. secs 1970 for this point
AZ DOUBLE 204.47500 .. source az for pnt
ZA DOUBLE 89.974000 .. za for this pnt
RAHR DOUBLE 0.23571587 .. J2000 right ascension in hours for ;
this point
DECD DOUBLE -66.452344 .. J2000 declination in deg for this point
PHASE LONG 226 .. phase in orbit 0..255
LAT LONG -50 .. north lattitude of sat sub orbit point
LON LONG 105 .. west longitude of sat sub orbit point
RANGEKM LONG 25677 .. slant range in kilometers to satellite
ORBITNUM LONG 4142 .. orbit number. increments once each orbit.
************************************************************
3. Compute satellite passes for a constellation of satellites
************************************************************
npts=satpassconst(satAr,/gps)
Returns satAr[31]. Each entry is the pass info for a single satellite
in the gps constellation.
help,satAr[0],/st
NPNTS LONG 92 .. pnts in pass for this satellite
SATNM STRING 'GPS16' .. sat Nm
ZAMIN FLOAT 18.8350 .. min za for pass
SECSMIN DOUBLE 1.2217464e+09 .. time for minza secs1970
P STRUCT -> SATPASS Array[150] .. pnts in pass
Note that satAr[0].p[150] is dimensioned as 150 but there are only
satAr[0].npts = 92 valid points in the array. The number of points
varies with each satellite pass.
************************************************************
4. plot passes for a satellite constellation
************************************************************
satpassplt,yymmdd=yymmddd,hhmmss=hhmmss,satAr=satAr,v=v,/glonass
Will plot the az,za for each of the glonass satellites for the given time.
The passInfo can be returned in satAr if you want. You can control
the vertical scale with v.
To get hardcopy with za 0 to 20 for 23sep08 141500 AST (when the
next L3 test is scheduled) you could:
pscol,'gpspass_1.ps',/full
hhmss=141500
yymmdd=080923
v=[0,20]
satpassplt,yymmdd=yymmdd,hhmmss=hhmmss,v=v,/gps
hardcopy
x
ldcolph
Note that the azimuth plotted is the source azimuth.
WARNINGS:
- the keyword: tlefile= or tledir= keyword has been
added to let you use non-standard locations for the
tlefiles. I've noticed that predict only allows
up to 48 characters for the entire filename..
So don't use long path/filenames...
************************************************************
for more info use
explain,satroutine
(See /pkg/rsi/local/libao/phil/sat/sat0intro.pro)
NAME:
satcmpangle - compute angle between ra,dec,jd and satellites
SYNTAX: satcmpangle,raHr,decDec,jd,passAr,distI
ARGS:
raHr[m]: float right ascension hours to use
decDeg[m]: float declination in degrees
jd[m] : double julian date
passAr[n]:{} array of satellite constellation info returned
from satpassplt()
RETURNS:
distI[m,n]: float distance from satellite to request position
DESCRIPTION:
Compute the angle in degrees between the requested ra,dec (j2000),jd and the
location of the satellites in passAr.
passAr comes from satpassplt( ...satAr=satAr,/radec). Be sure that the
/radec keyword is set in the call to satpassplt so that the ra,dec gets
computed..
(See /pkg/rsi/local/libao/phil/sat/satcmpangle.pro)
NAME: satdoc - routine list (single line) sat0intro - Intro to using the ao satellite prediction routines. satcmpangle - compute angle between ra,dec,jd and satellites satdoc - routine list (single line) satdocnames - list of routine names satfindtle - find tle file for satellite name satinfo - return tle entries for all satellites satinptlefile - input an entire tle file satlisttlefiles - return list of tle files satpass - compute satellite pass at AO satpassconst - compute satellite passes for a constellation satpassplt - plot a satellite constellation passes over AO satsetup - return setup info for sat routines
(See /pkg/rsi/local/libao/phil/sat/satdoc.pro)
NAME: satdocnames - list of routine names sat0intro satcmpangle satdoc satdocnames satfindtle satinfo satinptlefile satlisttlefiles satpass satpassconst satpassplt satsetup
(See /pkg/rsi/local/libao/phil/sat/satdocnames.pro)
NAME: satfindtle - find tle file for satellite name SYNTAX: tlefile=satfindtle(satNm) ARGS: satNm: string name of satellite to search for. RETURNS: tlefile:string name of tle file. '' if not found DESCRIPTION: This routine will look for a tle file based on the satNm
(See /pkg/rsi/local/libao/phil/sat/satfindtle.pro)
NAME:
satinfo - return tle entries for all satellites
SYNTAX: nsat=satinfo(satI,tledir=tledir,yymmdd=yymmdd)
ARGS:
KEYWORDS:
tledir: string directory to for tle's
def: /share/megs/predict/tle
yymmdd: long : if supplied, then search for this date in the archive.
RETURNS:
nsat: long number of satellites we found
satI[nsat]: {} array of struct holding satinfo
DESCRIPTION:
Return info on all of the satellites we have tle's for.
The returned structure contains:
help,satI,/st
NM STRING 'GIOVE-A'
TLEFILE STRING '/share/megs/phil/predict/tle/galileo.tle'
TLE STRUCT -> Array[1]
.. The tle info for each satellite
help,satI[0].tle,/st
SATNM STRING 'GIOVE-A'
SATNUM INT 28922
SATCLASS STRING 'U'
LAUNCHYR LONG 2005
LAUNCHNUM INT 51
LAUNCHPIECE STRING 'A '
EPOCHYR LONG 2008
EPOCHDAY DOUBLE 260.32344
TMDER1 DOUBLE 2.2000000e-07
TMDER2 STRING ' 00000-0'
DRAG DOUBLE 10000.000
EPHTYPE STRING '0'
ELMNUM INT 394
INCLINATION DOUBLE 56.055200
RAASCNODE DOUBLE 164.58550
ECCENTRICITY STRING '0007843'
ARGOFPERIGEE DOUBLE 331.59930
MEANANOMALY DOUBLE 28.417500
MEANMOTION DOUBLE 1.7019477
REVNUM LONG 1690
LINES STRING Array[3]
(See /pkg/rsi/local/libao/phil/sat/satinfo.pro)
NAME:
satinptlefile - input an entire tle file
SYNTAX: nsat=satinptlefile(filenm,tleAr,tledir=tledir)
ARGS:
filenm: string name of tle file to input. If no / in filename then
prepend default directory.
KEYWORDS:
tledir: string if supplied then use this directory to look for tle file
RETURNS:
nsat: long number of satellites found in the file
satAr[nsat]:{} array of tle entries found in file
DESCRIPTION:
Input all of the satellites from a tle file
for tle field definitions see:
http://celestrak.com/columns/v04n03/#FAQ01
(See /pkg/rsi/local/libao/phil/sat/satinptlefile.pro)
NAME: satlisttlefiles - return list of tle files SYNTAX: nfiles=satlisttlefiles(tlefiles,tledir=tledir,suf=suf) ARGS: KEYWORDS: tledir: string if supplied then the directory to look for tle file suf : string suffix for tle files. by default use txt,tle. yymmdd: long if supplied, then look in archive for data for this date. RETURNS: nfiles: long number of files we found tlefiles[nfiles]: array of files we founds DESCRIPTION: get a list of tle files in the requested directory (default is the default tle directory). If tledir is supplied then search this directory for any tle files. if yymmdd= is supplied then search archive for data for this date. The current search looks for tle data updated on this date. It may return nothing if a tle file was not modified on this date (need to broaden search criteria). it will have to run updatetle.sc on each file found data is written to tmp directory. NOTE: yymmdd and tledir are mutually exclusive...
(See /pkg/rsi/local/libao/phil/sat/satlisttlefiles.pro)
NAME:
satpass - compute satellite pass at AO
SYNTAX: npts=satpass(satNm,passI,yymmdd=yymmdd,hhmmss=hhmmss,$
jd=jd,nsecs=nsecs,tlefile=tlefile,radec=radec)
ARGS:
satNm: string name of satellite, must match name in tle file
KEYWORDS:
yymmdd: long date (AST) for pass.
hhmmss: long hour,min,sec of day (AST).If not provided find
first pass of day.
jd : double time for the pass
nsecs : long if provided then the number of secs to report
If not provided then do the entire pass. If
nsecs is provided, then the resolution is 1 second.
tlefile: string filename holding the two line elements for this sat.
if '/' not in name then prepend default path.
If this is not supplied then the program will search
all tle files for this satellite name
radec: If set (/radec) then include the ra,dec for each az,za position.
This takes a little longer to run.
RETURNS:
npts: long > 0 number of entries in passI.
< 0 error occurred.
passI[npts]: structure holding pass info for each time point.
DESCRIPTION:
Compute az,za,ra,dec for satellite pass over ao for a given day.
Use yymmdd,hhmmss or jd to specify when the passes should occur. If
no date/time is provided use the current time.
Passes will be computed that are above the horizon for the specified time.
(See /pkg/rsi/local/libao/phil/sat/satpass.pro)
NAME:
satpassconst - compute satellite passes for a constellation
SYNTAX: npts=satpassconst(passAr,yymmdd=yymmdd,hhmmss=hhmmss,jd=jd,$
gps=gps,iridium=iridium,niridium=niridium,galileo=galileo,beidou=beidou,$
globalstar=globalstar,$
radec=radec,verb=verb,tlefile=tlefile)
ARGS:
KEYWORDS:
gps: if set then use the gps constellations
iridium: if set then use the iridium constellations
niridium: if set then use the iridium-NEXT constellations
glonass: if set then use the glonass constellations
galileo: if set then use the galileo constellations
beidou : if set then use the chinese beidou constellations
globalstar: if set then use the globalstar constellations
tlefile: string if provided then read all sat from this tle file.
If you don't put a leading / then it will use
the default location.
satNmAr[]:string if tlefile is supplied then only include
satellites names in satNmAr[]
yymmdd: long date (AST) for pass.
hhmmss: long hour,min,sec of day (AST).If not provided find
first pass of day.
jd: double if provided then use this for the pass time.
nsecs: long Instead of entire pass, compute the location
once a second started at requested time for
nsecs. This gives fixed time resolution.
.. warning.. if a satellite is not visible during
the requested time, predict loops forever..
radec: if set then include ra,dec for each az,za position.
verb: if set then print tlefiles as they are input
RETURNS:
nsat: long > 0 number of satellites found
< 0 error occurred.
passAr[nsat]: array of structures holding pass info for each satellite
DESCRIPTION:
Compute az,za,ra,dec for satellites in the specified constellation
as the specified time. The all passes should be above the horizon at the
specified time.
(See /pkg/rsi/local/libao/phil/sat/satpassconst.pro)
NAME:
satpassplt - plot a satellite constellation passes over AO
SYNTAX: satpassplt,yymmdd=yymmdd,hhmmss=hhmmss,jd=jd,satAr=satAr,v=v,$
gps=gps,iridium=iridium,niridium=niridium,glonass=glonass,galileo=galileo,$
beidou=beidou,$
globalstar=globalstar,tlefile=tlefile,wait=wait,radec=radec,$
samepage=samepage,ln0=ln0,usearchive=usearchive
ARGS:
KEYWORDS:
yymmdd: long if supplied then the AST date for the pass
hhmmss: long if supplied then the AST time for the pass
jd : double if supplied then the julian date for the pass
nsecs : long instead of plotting an entire pass, plot nsecs
points starting at requested time spaced by 1 sec.
.. warning. If a satellite is not visible during
this time, predict seems to loop forever...
v[2] : float if supplied then then min, max za for plotting.
gps : if set then plot the gps constellation
iridium: if set then plot the iridium constellation
niridium: if set then plot the iridium-NEXT constellation
glonass: if set then plot the glonass constellation
galileo : if set then plot the galileo constellation
beidou : if set then plot the beidou constellation
globalstar: if set then plot the globalstar constellation
tlefile :string if provided then ignore constellation names. Plot
all satellites in this file
satNmAr[] :string if supplied with tlefile then only plot these sat
names.
wait : if set then wait for keyboard input before plotting
the next page. This is only needed for iridium,niridium and
globalstar (they have more than 32 satellites).
radec : If set then include the ra,dec in the returned info
This slows down the routine a little. This is only
used if satAr is supplied to return the info in.
samepage : if set then continue plotting on the current page
useful for constellation with only a few satellites
ln0 : int first linenumber for display of first sat name.
useful if you are using samepage. Then you can
have the sat name appear in the frame you are writing in.
values .. about 0 to 31
usearchive: int if set then search archive for date. Without this, it uses
the current tle to the date,time.
RETURNS:
satAr[nsat]: {} strucuture containing satellite info for each pass and
point within a pass.
DESCRIPTION:
Plot the passes over ao for the specified constellation at a given time.
The time can be specified by yymmdd,hhmmss keywords or jd (julian date). If no
date is specified then the current time is used.
A satellite pass is included in the plot if any portion of a pass is
above the AO horizon at the specified time.
Only one constellation can be specified per call. If no constellation
is specified then gps is used.
The first point (in time) of the pass will have a rectangle. All other points wil
have a +. Points are separated by about 2-3 degrees in orbital phase (they are not spaced
equidistant in time).
A maximum of 32 satellites can be plotted per page. If you want to
see each page as it is generated either make a hardcopy, or use the
/wait keyword to wait before plotting the next page.
satAr is an array satAr[31] .. one for each satellite.
L> help,satAr,/st
NPNTS LONG 92 .. number of points in pass (valid pnts in P[])
SATNM STRING 'GPS16' .. name of satellite
ZAMIN FLOAT 18.8150 .. minimum za for this pass
SECSMIN DOUBLE 1.2221771e+09 .. time secs 1970 for za Min.
P STRUCT SATPASS Array[150] .. array of points for each pass. Only the first
satAr[i].npnts are valid for this pass.
the pass structure P contains:
IDL> help,satAr.p,/st
JD DOUBLE 2.7793265e+08 .. jd for this point
SECS DOUBLE 1.2221659e+09 .. secs 1970 for this point
AZ DOUBLE 204.47500 .. source az for pnt
ZA DOUBLE 89.974000 .. za for this pnt
RAHR DOUBLE 0.23571587 .. J2000 right ascension in hours for this point
DECD DOUBLE -66.452344 .. J2000 declination in deg for this point
PHASE LONG 226 .. phase in orbit 0..255
LAT LONG -50 .. north lattitude of sat sub orbit point
LON LONG 105 .. west longitude of sat sub orbit point
RANGEKM LONG 25677 .. slant range in kilometers to satellite
ORBITNUM LONG 4142 .. orbit number. increments once each orbit.
EXAMPLE:
idl
@satinit
yymmdd=080923
hhmmss=141500
satpassplt,yymmdd=yymmdd,hhmmss=hhmmss,satAr=satAr,/gps
(See /pkg/rsi/local/libao/phil/sat/satpassplt.pro)
NAME:
satsetup - return setup info for sat routines
SYNTAX: satSetupI=satsetup()
ARGS: none
KEYWORDS: none
RETURNS:
satSetupI:{} returns strucuture containing locations of various files/dir.
DESCRIPTION:
Call satsetup() to get the default locations for files and
directories.
(See /pkg/rsi/local/libao/phil/sat/satsetup.pro)