[daip] [!5849]: aips - CVEL rest frequency error in AIPS Dec 31, 2014 version ?

[Eric Greisen]

Eric Greisen updated #5849
--------------------------

       Staff (Owner): Eric Greisen (was: -- Unassigned --)
              Status: Closed (was: Open)
                 Due: - Cleared - (was: 10 December 2014 12:00 AM)

CVEL rest frequency error in AIPS Dec 31, 2014 version ?
--------------------------------------------------------

           Ticket ID: 5849
                 URL: https://help.nrao.edu/staff/index.php?/Tickets/Ticket/View/5849
           Full Name: Yogesh Chandola
               Email: yogesh.chandola at gmail.com
             Creator: User
          Department: AIPS Data Processing
       Staff (Owner): Eric Greisen
                Type: Issue
              Status: Closed
            Priority: Default
      Template Group: Default
             Created: 06 December 2014 06:55 AM
             Updated: 06 December 2014 08:05 PM



POPS uses single precision floating point for all values.
This has limited accuracy.  CVEL converts the 2 adverb values
each into doubles and then adds them.  This still runs a risk
of some loss of accuracy.  10 Hz will not matter at all in HI
work, but using 1.4204E9 , 5752 might be more accurate...

Eric Greisen




------------------------------------------------------
Staff CP:  https://help.nrao.edu/staff