• radFromDeg
  • radToDeg
  • lbToXyz
  • xyzToLb
  • vS2tp
  • vTp2s
  • dayFromTime
  • coordPrecess
  • coordPreNut
  • earthPosVel
  • radFromDMS
  • radFromHMS
  • DMSToDeg
  • HMSToDeg
  • radToDMS
  • radToHMS
  • degToDMS
  • degToHMS
  • sepGet
  • tstampNew
  • tstampNow
  • tstampDel
  • deltaTstamp
  • tstampFromMJD
  • tstampToMJD
  • tstampIncr
  • tstampToDate
  • tstampToTime
  • tstampToLst
  • tstampToTwilight
  • planetRaDec
  • planetRiseSet
  • vFitxy
  • vTrans
  • atRefro
  • atOap
  • atAop
  • atMean2Apparent
  • atAberrationApply
  • atVAberrationApply
  • atAberrationGet
  • atAzEl2HaDec
  • velFromTstamp
  • meanToApparent
  • pmApply
  • epj2mjd
  • mjd2epj
  • datFromMjd
  • tclSlalib

       TCL support for SLALIB (astrometry) routines
    
    
    
    

    radFromDeg

    C ROUTINE CALLED:
    atRadFromDeg in atSlalib.c
    

    Convert degrees to radians

    TCL USAGE:
      USAGE: radFromDeg deg
    
    TCL HELP STRING:
      Convert degrees to radians
    
    

    radToDeg

    C ROUTINE CALLED:
    atRadToDeg in atSlalib.c
    

    Convert radians to degrees

    TCL USAGE:
      USAGE: radToDeg rad
    
    TCL HELP STRING:
      Convert radians to degrees
    
    

    lbToXyz

    C ROUTINE CALLED:
    slaDcs2c in slalib library
    

    Convert (long, lat) in degrees to (x, y, z)

    TCL USAGE:
      USAGE: lbToXyz longitude latitude
    
    TCL HELP STRING:
      Convert (long, lat) in degrees to (x,y,z)
    
    

    xyzToLb

    C ROUTINE CALLED:
    slaDcc2s in slalib library
    

    Convert (x, y, z) to (long, lat) in degrees

    TCL USAGE:
      USAGE: xyzToLb x y z
    
    TCL HELP STRING:
      Convert (x,y,z) to (long, lat) in degrees
    
    

    vS2tp

    C ROUTINE CALLED:
    atVS2tp in atSlalib.c
    
    
    TCL SYNTAX:
      vS2tp  "<vRa>" "<vDec>" "<ra>" "<dec>" 
    
    TCL HELP STRING:
      Project spherical coordinates to those on a tangential plane. The tangential point is given by ra and dec in degrees.
    
    TCL ARGUMENTS:
                     : 
      "<vRa>"      : vector of RAs to use
      "<vDec>"     : vector of DECs to use
      "<ra>"       : tangential point ra
      "<dec>"      : tangential point dec
    
    

    vTp2s

    atVTp2s in atSlalib.c
    
    
    TCL SYNTAX:
      vTp2s  "<vXi>" "<vEta>" "<ra>" "<dec>" 
    
    TCL HELP STRING:
      Project tangential plane to spherical coordinates. The tangential point is given by ra and dec in degrees.
    
    TCL ARGUMENTS:
                     : 
      "<vXi>"      : vector of xi's (in degrees) to use (will be modified)
      "<vEta>"     : vector of eta's (in degrees) to use (will be modified)
      "<ra>"       : tangential point ra
      "<dec>"      : tangential point dec
    
    

    dayFromTime

    C ROUTINE CALLED:
    atDayFromTime in atSlalib.c
    
    
    TCL USAGE:
      
    USAGE: dayFromTime hh:mm:sec
    
    TCL HELP STRING:
      
    Convert the hh:mm:sec string to days
    
    

    coordPrecess

    C ROUTINE CALLED:
    slaPreces in slalib library
    
    
    TCL USAGE:
      
    USAGE: coordPrecess raInDegrees decInDegrees startepoch endepoch FK4/FK5
    
    TCL HELP STRING:
      
    Precess coordinates from one epoch to another, return as a tcl list
    
    

    coordPreNut

    C ROUTINES CALLED:
    slaDcs2c, slaPrenut, slaDmxv, slaDimxv, and  slaDcc2s in slalib library
    

    This routine performs both precession and nutation on a coordinate. Nutation has an amplitude of about 9" and a period of 18.6 years.

    Epoch" is the epoch of true coordinates on the sky, without refraction and aberration). meanEpoch" is the epoch of mean coordinates (catalog). The routine takes mean into true coordinates. Optionally one may reverse the direction, from true to mean.

    The difference between this routine and coordPrecess is that this one adds nutation. The difference between this routine and atMean2Apparent is primarily that the latter adds annual aberration and secondarily that the latter adds light deflection effects.

    TCL SYNTAX:
      coordPreNut  "<ra>" "<dec>" "<epoch>" "-meanEpoch" "-reverse" 
    
    TCL HELP STRING:
      Precess and nutate coordinates from catalog to true coordinates, in FK5.
    return a tcl list of coordinates
    
    TCL ARGUMENTS:
                     : 
      "<ra>"       : ra in degrees
      "<dec>"      : dec in degrees
      "<epoch>"    : the true epoch TSTAMP
      "-meanEpoch"   : the TSTAMP holding the epoch of the mean (catalog) coordinates. (defaults to J2000)
      "-reverse"     : if 1, reverse the sense, taking true to mean coordinates
    
    

    earthPosVel

    C ROUTINES CALLED:
    slaEpj, slaEvp in slalib library
    
    
    TCL SYNTAX:
      earthPosVel  "<mjd>" "-epoch" "-helio" 
    
    TCL HELP STRING:
      Find the position and velocity of the Earth in barycentric coordinates
    Positions are in mean FK5 coords, units of AU. Velocities are AU/s.
    
    TCL ARGUMENTS:
                     : 
      "<mjd>"      : modified julian date
      "-epoch"       : the TSTAMP holding the epoch of the mean coordinates. (defaults to J2000)
      "-helio"       : if 1,  coordinates returned are heliocentric (defaults to barycentric)
    
    

    radFromDMS

    C ROUTINE CALLED:
    atRadFromDMS in atSlalib.c
    
    
    TCL USAGE:
      
    USAGE: radFromDMS hh:mm:sec
    
    TCL HELP STRING:
      
    Convert the dd:mm:sec string to radians
    
    

    radFromHMS

    C ROUTINE CALLED:
    atRadFromHMS in atSlalib.c
    
    
    TCL USAGE:
      
    USAGE: radFromHMS hh:mm:sec
    
    TCL HELP STRING:
      
    Convert the hh:mm:sec string to radians
    
    

    DMSToDeg

    C ROUTINE CALLED:
    atDMSToDeg in atSlalib.c
    
    
    TCL USAGE:
      
    USAGE: DMSToDeg hh:mm:sec
    
    TCL HELP STRING:
      
    Convert the dd:mm:sec string to degrees
    
    

    HMSToDeg

    C ROUTINE CALLED:
    atHMSToDeg in atSlalib.c
    
    
    TCL USAGE:
      
    USAGE: HMSToDeg hh:mm:sec
    
    TCL HELP STRING:
      
    Convert the hh:mm:sec string to degrees
    
    

    radToDMS

    C ROUTINE CALLED:
    atRadToDMS in atSlalib.c
    
    
    TCL USAGE:
      
    USAGE: radToDMS radians
    
    TCL HELP STRING:
      
    Convert radians to dd:mm:sec string
    
    

    radToHMS

    C ROUTINE CALLED:
    atRadToHMS in atSlalib.c
    
    
    TCL USAGE:
      
    USAGE: radToHMS radians
    
    TCL HELP STRING:
      
    Convert radians to hh:mm:sec string
    
    

    degToDMS

    C ROUTINE CALLED:
    atDegToDMS in atSlalib.c
    
    
    TCL USAGE:
      
    USAGE: degToDMS degrees
    
    TCL HELP STRING:
      
    Convert degrees to dd:mm:sec string
    
    

    degToHMS

    C ROUTINE CALLED:
    atDegToHMS in atSlalib.c
    
    
    TCL USAGE:
      
    USAGE: degToHMS degrees
    
    TCL HELP STRING:
      
    Convert degrees to hh:mm:sec string
    
    

    sepGet

    C ROUTINE CALLED:
    slaDsep in slalib library
    
    
    TCL USAGE:
      USAGE:  sepGet ra1 dec1 ra2 dec2
    
    TCL HELP STRING:
      Given two positions (in degrees) return 
    the separation angle (in degrees)
    
    

    tstampNew

     C ROUTINE CALLED:
     atTstampNew in atSlalib.c
    
    
    TCL SYNTAX:
      tstampNew  "<year>" "<month>" "<day>" "<hour>" "<minute>" "<second>" 
    
    TCL HELP STRING:
      Make a new TSTAMP with the specified date and time.
    RETURN:  handle to the TSTAMP
    
    TCL ARGUMENTS:
                     : 
      "<year>"     : year, including centuries:  1995, for example
      "<month>"    : month, from 1 to 12
      "<day>"      : day of the month, from 1 to 31
      "<hour>"     : hour, from 0 to 23
      "<minute>"   : minute, from 0 to 59
      "<second>"   : seconds, from 0.0 to 59.999999
    
    

    tstampNow

     C ROUTINE CALLED:
     atTstampNow in atSlalib.c
    
    
    TCL SYNTAX:
      tstampNow  "-timetype" 
    
    TCL HELP STRING:
      Make new TSTAMP with the current GMT.
    RETURN:  handle to the TSTAMP
    
    TCL ARGUMENTS:
                     : 
      "-timetype"    : UT(default) or TAI
    
    

    tstampDel

     C ROUTINE CALLED:
     atTstampDel in atSlalib.c
    
    
    TCL SYNTAX:
      tstampDel  "<tstamp>" 
    
    TCL HELP STRING:
      delete a TSTAMP
    
    TCL ARGUMENTS:
                     : 
      "<tstamp>"   : the tstamp to delete
    
    

    deltaTstamp

     C ROUTINE CALLED:
     atTstampToMJD in atSlalib.c
     
    
    TCL SYNTAX:
      deltaTstamp  "<tstamp1>" "<tstamp2>" 
    
    TCL HELP STRING:
      Return the tstamp1 - tstamp2 in seconds
    
    TCL ARGUMENTS:
                     : 
      "<tstamp1>"  : The first tstamp
      "<tstamp2>"  : The tstamp to subtract from the first tstamp
    
    

    tstampFromMJD

     C ROUTINE CALLED:
     atTstampFromMJD in atSlalib.c
    
    
    TCL SYNTAX:
      tstampFromMJD  "<MJD>" 
    
    TCL HELP STRING:
      Create a tstamp corresponding to a MJD date
    
    TCL ARGUMENTS:
                     : 
      "<MJD>"      : the MJD date
    
    

    tstampToMJD

     C ROUTINE CALLED:
     atTstampToMJD in atSlalib.c
     
    
    TCL SYNTAX:
      tstampToMJD  "<tstamp>" 
    
    TCL HELP STRING:
      Return the MJD date corresponding to the TSTAMP
    
    TCL ARGUMENTS:
                     : 
      "<tstamp>"   : the TSTAMP
    
    

    tstampIncr

     C ROUTINE CALLED:
     atTstampIncr in atSlalib.c
    
    
    TCL SYNTAX:
      tstampIncr  "<tstamp>" "<seconds>" 
    
    TCL HELP STRING:
      Increment TSTAMP by seconds
    
    TCL ARGUMENTS:
                     : 
      "<tstamp>"   : the tstamp to increment
      "<seconds>"  : number of seconds to increment 
    
    

    tstampToDate

     C ROUTINE CALLED:
     atTstampToDate in atSlalib.c
     
    
    TCL SYNTAX:
      tstampToDate  "<tstamp>" 
    
    TCL HELP STRING:
      return the formatted date from the TSTAMP
    
    TCL ARGUMENTS:
                     : 
      "<tstamp>"   : the tstamp
    
    

    tstampToTime

     C ROUTINE CALLED:
     atTstampToTime in atSlalib.c
     
    
    TCL SYNTAX:
      tstampToTime  "<tstamp>" 
    
    TCL HELP STRING:
      return the formatted time from the TSTAMP
    
    TCL ARGUMENTS:
                     : 
      "<tstamp>"   : the tstamp
    
    

    tstampToLst

     C ROUTINE CALLED:
     atTstampToLst in atSlalib.c
     
    
    TCL SYNTAX:
      tstampToLst  "<tstamp>" "-long" "-timetype" 
    
    TCL HELP STRING:
      return the formatted Lst from the TSTAMP
    
    TCL ARGUMENTS:
                     : 
      "<tstamp>"   : the tstamp
      "-long"        : observatory longitude, at_site_longitude default
      "-timetype"    : UT(default) or TAI
    
    

    tstampToTwilight

     C ROUTINE CALLED:
      atTstampToTwilight in atSlalib.c
     
    
    TCL SYNTAX:
      tstampToTwilight  "<tstamp>" "-degrees" 
    
    TCL HELP STRING:
      return the formatted Lst from the TSTAMP
    
    TCL ARGUMENTS:
                     : 
      "<tstamp>"   : the tstamp
      "-degrees"     : degrees below the horizon for darkness
    
    

    planetRaDec

    C ROUTINE CALLED: atPlanetRaDec in atSlalib.c
    
    

    Finds the RA and DEC at a given time for Sun, Moon, or planet. The planet numbers (np) are given by:

    1 Mercury 2 Venus 3 Moon 4 Mars 5 Jupiter 6 Saturn 7 Uranus 8 Neptune x Pluto (not supported) 10 Sun
    TCL SYNTAX:
      planetRaDec  "<tstamp>" "<np>" "-longitude" "-lat" 
    
    TCL HELP STRING:
      return the RA and DEC of the Sun, Moon, or planet in a keyed list
    
    TCL ARGUMENTS:
                     : 
      "<tstamp>"   : the tstamp
      "<np>"       : which planet, moon=3, sun=10
      "-longitude"   : west longitude of observatory, at_site_longitude
      "-lat"         : north latitude of observatory, at_site_latitude default
    
    

    planetRiseSet

    C ROUTINE CALLED: 
    atPlanetRiseSet in atSlalib.c
    

    Finds the rise and set times for Sun, Moon, or planet. The planet numbers (np) are given by:

    1 Mercury 2 Venus 3 Moon 4 Mars 5 Jupiter 6 Saturn 7 Uranus 8 Neptune x Pluto (not supported) 10 Sun Time zones are hours from GMT. Zenith distance defaults to 108 degrees.
    TCL SYNTAX:
      planetRiseSet  "<tstamp>" "<np>" "-longitude" "-lat" "-tz" "-zd" 
    
    TCL HELP STRING:
      return the formatted Lst from the TSTAMP
    
    TCL ARGUMENTS:
                     : 
      "<tstamp>"   : the tstamp
      "<np>"       : which planet, moon=3, sun=10
      "-longitude"   : longitude of observatory, at_site_longitude default
      "-lat"         : latitude of observatory, at_site_latitude default
      "-tz"          : timezone, GMT=0, default
      "-zd"          : zenith distance that defines horizon, 108 degrees default
    
    

    vFitxy

    C ROUTINE CALLED:
    atVFitxy in atSlalib.c
    

    Fit a linear model to relate the two sets of points that have already been matched. vxe,vye) are the expected positions of the points and vxm,vym) are the measured positions of the points. nfit must be 4 for solid body fit, or 6 for full linear fit. The model returned in the TRANS structure transforms from the measured points to the expected points. Only the affine terms are fit; the higher-order distortion and color terms are set to 0. The error flag is returned - 0 is okay.

    TCL SYNTAX:
      vFitxy  "<trans>" "<vxe>" "-vxe" "<vye>" "-vyee" "<vxm>" "-vxme" "<vym>" "-vxme" "-mask" "<nfit>" 
    
    TCL HELP STRING:
      Fit a linear model to relate the two sets of points
    
    TCL ARGUMENTS:
                     : 
      "<trans>"    : the trans
      "<vxe>"      : x expected
      "-vxe"         : x expected error
      "<vye>"      : y expected
      "-vyee"        : y expected error
      "<vxm>"      : x measured
      "-vxme"        : x measured error
      "<vym>"      : y measured
      "-vxme"        : x measured error
      "-mask"        : mask values; use pt only if set to 1
      "<nfit>"     : 4 or 6 to determine type of fit
    
    

    vTrans

       Applies a TRANS to two VECTOR's containing the measured x and y positions.
       Only the affine terms are applied; the higher-order distortion and color
       terms are ignored.
    
    C ROUTINE CALLED:
    atVTrans in atSlalib.c
    
    
    TCL SYNTAX:
      vTrans  "<trans>" "<vxm>" "-vxme" "<vym>" "-vyme" 
    
    TCL HELP STRING:
      Use the trans to transform the (x,y) pairs in 
    vxm and vym.  The values in the VECTORs are transformed 
    in the same VECTORs and 
    the errors are set to zero.
    
    TCL ARGUMENTS:
                     : 
      "<trans>"    : the trans
      "<vxm>"      : x values
      "-vxme"        : x errors
      "<vym>"      : y values
      "-vyme"        : y errors
    
    

    atRefro

    C ROUTINE CALLED:
    slaRefro in slalib library
    
    
    TCL SYNTAX:
      atRefro  "<zd>" "<wavelength>" "-height" "-temp" "-pressure" "-humidity" "-latitude" "-lapse" "-err" 
    
    TCL HELP STRING:
      Calculate a refraction correction
    
    TCL ARGUMENTS:
                     : 
      "<zd>"       : zenith dist (degrees)
      "<wavelength>" : effective wavelength (angstroms)
      "-height"      : above sea level meters (default 3000m)
      "-temp"        : temp (K) (default 300)
      "-pressure"    : pressure (mbar) (default 700)
      "-humidity"    : humidity (frac) (default 0.3)
      "-latitude"    : latitude (degrees) (default 32.8)
      "-lapse"       : temp lapse K/m (default 0.0065)
      "-err"         : precision of calc (default 1d-10)
    
    

    atOap

    C ROUTINE CALLED:
    slaOap in slalib library
    
    
    TCL SYNTAX:
      atOap  "<type>" "<obs1>" "<obs2>" "<date>" "-delut" "-longitude" "-latitude" "-height" "-xp" "-yp" "-temp" "-pressure" "-humidity" "-wavelength" "-lapse" 
    
    TCL HELP STRING:
      Calculate apparent position from observed
    
    TCL ARGUMENTS:
                     : 
      "<type>"     : Is first coord RA (R or r), HA (H or h) or Az (A or a)
      "<obs1>"     : RA, HA, or Az (degrees)
      "<obs2>"     : DEC (R|r|H|h) or Zenith Dist (A|a) (degrees)
      "<date>"     : Date (mjd)
      "-delut"       : UT1-UTC (UTC seconds), default=0.0 (which is wrong)
      "-longitude"   : west (+ve) longitude of observatory, at_site_longitude
      "-latitude"    : latitude (degrees) at_site_latitude
      "-height"      : above sea level meters (default at_site_altitude)
      "-xp"          : x polar motion (default = 0.0)
      "-yp"          : y polar motion (default = 0.0)
      "-temp"        : temp (K) (default 300)
      "-pressure"    : pressure (mbar) (default 700)
      "-humidity"    : humidity (frac) (default 0.3)
      "-wavelength"  : effective wavelength, default=4770 A (g')
      "-lapse"       : temp lapse K/m (default 0.0065)
    
    

    atAop

    C ROUTINE CALLED:
    slaAop in slalib library
    
    
    TCL SYNTAX:
      atAop  "<apra>" "<apdec>" "<date>" "-delut" "-longitude" "-latitude" "-height" "-xp" "-yp" "-temp" "-pressure" "-humidity" "-wavelength" "-lapse" 
    
    TCL HELP STRING:
      Calculate observed position from apparent
    
    TCL ARGUMENTS:
                     : 
      "<apra>"     : apparent RA (degrees)
      "<apdec>"    : apparent DEC (degrees)
      "<date>"     : Date (mjd)
      "-delut"       : UT1-UTC (UTC seconds), default=0.0 (which is wrong)
      "-longitude"   : west (+ve) longitude of observatory, at_site_longitude
      "-latitude"    : latitude (degrees) at_site_latitude
      "-height"      : above sea level meters (default at_site_altitude)
      "-xp"          : x polar motion (default = 0.0)
      "-yp"          : y polar motion (default = 0.0)
      "-temp"        : temp (K) (default 300)
      "-pressure"    : pressure (mbar) (default 700)
      "-humidity"    : humidity (frac) (default 0.3)
      "-wavelength"  : effective wavelength, default=4770 A (g')
      "-lapse"       : temp lapse K/m (default 0.0065)
    
    

    atMean2Apparent

    C ROUTINE CALLED:
    slaMap in slalib library
    
    
    TCL SYNTAX:
      atMean2Apparent  "<ra>" "<dec>" "<tstampName>" 
    
    TCL HELP STRING:
      Mean To Apparent coord conversion
    
    TCL ARGUMENTS:
                     : 
      "<ra>"       : mean ra (degrees)
      "<dec>"      : mean dec (degrees)
      "<tstampName>" : tstamp giving time and date
    
    

    atAberrationApply

    C ROUTINE CALLED:
    atAberrationApply in atSlalib.c
    
    
    TCL SYNTAX:
      atAberrationApply  "<mjd>" "<epoch>" "<ra>" "<dec>" 
    
    TCL HELP STRING:
      Find and apply delta position due to annual aberration
    
    TCL ARGUMENTS:
                     : 
      "<mjd>"      : Modified Julian Date
      "<epoch>"    : epoch (negative for FK5 at mjd)
      "<ra>"       : mean ra (degrees)
      "<dec>"      : mean dec (degrees)
    
    

    atVAberrationApply

    C ROUTINE CALLED:
    atVAberrationApply in atSlalib.c
    
    
    TCL SYNTAX:
      atVAberrationApply  "<mjd>" "<epoch>" "<ra>" "<dec>" 
    
    TCL HELP STRING:
      Find and apply delta position due to annual aberration
    
    TCL ARGUMENTS:
                     : 
      "<mjd>"      : Modified Julian Date
      "<epoch>"    : epoch (negative for FK5 at mjd)
      "<ra>"       : VECTOR of mean ras (degrees)
      "<dec>"      : VECTOR of mean decs (degrees)
    
    

    atAberrationGet

    C ROUTINE CALLED:
    atAberrationGet in atSlalib.c
    
    
    TCL SYNTAX:
      atAberrationGet  "<vx>" "<vy>" "<vz>" "<ra>" "<dec>" 
    
    TCL HELP STRING:
      Find delta position due to annual aberration
    
    TCL ARGUMENTS:
                     : 
      "<vx>"       : x velocity (units of c)
      "<vy>"       : y velocity (units of c)
      "<vz>"       : z velocity (units of c)
      "<ra>"       : mean ra (degrees)
      "<dec>"      : mean dec (degrees)
    
    

    atAzEl2HaDec

    Convert azimuth and elevation to hour angle and declination.  For example,
    if the azimuth and elevation are for an actual pointing of a telescope, this
    will return the observed place hour angle and declination.  If the effects of
    refraction have been removed from the elevation, then the apparent
    topocentric hour angle and declination are returned.  This is simply
    a wrapper for SLALIB's slaDH2E().  It returns the hour angle and declination
    both in degrees) as a TCL keyed list (with keys "ha" and "dec",
    respectively).
    

    C ROUTINE CALLED: slaDh2e in slalib library

    TCL SYNTAX:
      atAzEl2HaDec  "<az>" "<el>" "<latitude>" 
    
    TCL HELP STRING:
      (Azimuth,elevation) to (hour angle,declination) conversion
    
    TCL ARGUMENTS:
                     : 
      "<az>"       : azimuth (degrees, north=0, east=+90)
      "<el>"       : elevation (degrees
      "<latitude>" : geodetic latitude (degrees)
    
    

    velFromTstamp

    C ROUTINE CALLED:
    atVelocityFromTstamp in atSlalib.c
    
    
    TCL SYNTAX:
      velFromTstamp  "<tstamp>" "<vel>" 
    
    TCL HELP STRING:
      Find the geocentric apparent velocity of the APO observatory at TSTAMP
    
    TCL ARGUMENTS:
                     : 
      "<tstamp>"   : time to get the velocity
      "<vel>"      : a vector of dimension 6 which will contain the x,y,z geocentric apparent position (in AU) and velocity, in AU/sec at x, y, z, xdot, ydot, zdot
    
    

    meanToApparent

    C ROUTINE CALLED:
    atMeanToApparent in atSlalib.c
    
    
    TCL SYNTAX:
      meanToApparent  "-epoch" "<mjd>" "<ra>" "<dec>" 
    
    TCL HELP STRING:
      Convert mean to apparent place ignoring parallax and proper motion.  Returns a keyed list of ra and dec, the apparent place
    
    TCL ARGUMENTS:
                     : 
      "-epoch"       : epoch of mean equinox to be used (Julian) defaults to J2000.0
      "<mjd>"      : when to do the transformation
      "<ra>"       : mean ra (degrees)
      "<dec>"      : mean dec (degrees)
    
    

    pmApply

    C ROUTINE CALLED:
    slaPm in slalib library
    
    
    TCL SYNTAX:
      pmApply  "<r0>" "<d0>" "<pr>" "<pd>" "-px" "-rv" "<mjd0>" "<mjd1>" 
    
    TCL HELP STRING:
      Apply proper motion
    
    TCL ARGUMENTS:
                     : 
      "<r0>"       : initial ra (degrees)
      "<d0>"       : initial dec (degrees)
      "<pr>"       : ra proper motion (degrees/year)
      "<pd>"       : dec proper motion (degrees/year)
      "-px"          : parallax (arcsec)
      "-rv"          : radial velocity km/sec (+ve if receding)
      "<mjd0>"     : start epoch as an MJD
      "<mjd1>"     : end epoch as an MJD
    
    

    epj2mjd

    C ROUTINE CALLED:
    slaEpj2d in slalib library
    
    
    TCL SYNTAX:
      epj2mjd  "<epj>" 
    
    TCL HELP STRING:
      Convert Julian Epoch to MJD
    
    TCL ARGUMENTS:
                     : 
      "<epj>"      : Julian Epoch
    
    

    mjd2epj

    C ROUTINE CALLED:
    slaEpj in slalib library
    
    
    TCL SYNTAX:
      mjd2epj  "<mjd>" 
    
    TCL HELP STRING:
      Convert MJD to Julian Epoch
    
    TCL ARGUMENTS:
                     : 
      "<mjd>"      : Modified Julian Date
    
    

    datFromMjd

    C ROUTINE CALLED:
    slaDat in slalib library
    
    
    TCL SYNTAX:
      datFromMjd  "<mjd>" 
    
    TCL HELP STRING:
      Convert MJD to Julian Epoch
    
    TCL ARGUMENTS:
                     : 
      "<mjd>"      : Modified Julian Date