• airmassFind
  • airmassFromZd
  • meridianAirmassFind
  • airmassFindHaDec
  • zdDec2Ha
  • tclAirmass

    ABSTRACT:
    
    Routines to calculate airmass
    
    

    airmassFind

      C ROUTINE CALLED:
    		atAirmassFind in atAirmass.c
    
    

    Calculate the airmass at APO given the RA in degrees, the DEC in degrees, a UT timestamp.

    TCL SYNTAX:
      airmassFind  "<ra>" "<dec>" "<ut>" 
    
    TCL HELP STRING:
      Find the airmass of an object at RA,Dec, at time UT.
    Finds airmass at epoch of coordinates, at the latitude of APO.
    
    TCL ARGUMENTS:
                     : 
      "<ra>"       : right ascension in decimal degrees
      "<dec>"      : declination in decimal degrees
      "<ut>"       : tstamp object
    
    

    airmassFromZd

      C ROUTINE CALLED:
    		atAirmassFromZd in atAirmass.c
    
    

    Nothing but a wrapper to sla_Airmas which takes a zenith distance. This is specifically for use when one might be tempted to simply use sec(z), which will incur 0.25% errors at the Survey limit without any real good reason for doing so.

    TCL SYNTAX:
      airmassFromZd  "<zd>" 
    
    TCL HELP STRING:
      Find the airmass of an object at Zd.
    
    TCL ARGUMENTS:
                     : 
      "<zd>"       : zenith distance in decimal degrees
    
    

    meridianAirmassFind

      C ROUTINE CALLED:
    		atMeridianAirmassFind in atAirmass.c
    
    

    Calculate the meridian airmass at APO the DEC in degrees.

    TCL SYNTAX:
      meridianAirmassFind  "<dec>" 
    
    TCL HELP STRING:
      Find the meridian airmass of an object at Dec.
    Finds airmass at epoch of coordinates, at the latitude of APO.
    
    TCL ARGUMENTS:
                     : 
      "<dec>"      : declination in decimal degrees
    
    

    airmassFindHaDec

      C ROUTINE CALLED:
    		atAirmassFindHaDec in atAirmass.c
    
    

    Calculate the airmass at APO from the HA in hours and the DEC in degrees.

    TCL SYNTAX:
      airmassFindHaDec  "<ha>" "<dec>" 
    
    TCL HELP STRING:
      Find the airmass of an object at Ha,Dec.
    Finds airmass at epoch of coordinates, at the latitude of APO.
    
    TCL ARGUMENTS:
                     : 
      "<ha>"       : hour angle in hours
      "<dec>"      : declination in decimal degrees
    
    

    zdDec2Ha

      C ROUTINE CALLED:
    		atZdDec2Ha in atAirmass.c
    
    

    Calculate the HA (hours) from the zenith distance (degrees) and dec (degrees).

    TCL SYNTAX:
      zdDec2Ha  "<zd>" "<dec>" 
    
    TCL HELP STRING:
      Find the HA given ZD and DEC
    Finds HA at epoch of coordinates, at the latitude of APO.
    
    TCL ARGUMENTS:
                     : 
      "<zd>"       : zenith distance in degrees 
      "<dec>"      : declination in degrees