Intro:

18mar19: testing cband moon mapping

    The cima radecmap pattern was used to do a few strips across the moon. The setup was:

• the setup is under a3128/moon_190318.cmd
• you need to use the untested version of cima (the others will bomb on the ephemeris coordinates (more info)
• There is still a kludge needed in the catalog files...
• the ephemeris tracking really doesn't care about the  ra,dec coordinates.. it gets the from the ephemeris file. so i usually just put 1,2
• the cima software using the ra,dec coordinates in the file to do things like compute the correction for great circle extents..
• So you need to put an ra,dec in the catalog file  that is say from the middle of your observation.. so the great circle computations work.
• I looked at the error from the 18mar19 run, and it was less than an arcsecond in length over the enter run..
• The coordinates recorded in crval2,3 are correct.. it only affects the extent.
• Some of the other header locations (offset_ra,offset_dec ,etc) that are normally used for mapping are incorrect since the ra,dec for the center is continually changing.
• To get the offsets:
• read the ephemeris file
• get the times for each spectral sample
• interpolate the center of the moon for each time sample.
• Then use crval2,3 and the computed center to get the ra,dec offset.
• I noticed (at least offline) the when using the command file to load the .conf file, it didn't seem to pick up the radecmap params..
  
• manually loading the config seemed to work..
  
• ra strips:
  
• 45 arcmin long (great circle)
• 60 secs data/strip
• .5 sec spectral integration (120 spectra/strip)
• dec:
• The dec extent was also 45 amin
• the dec was stepped .5 amin each strip
• the telescope was driven in both directions (alternating between strips).
• A cal on,off was done with 1 second integration at each.
• strips 0..4 had calonoff, stripData, calonoff
• After that i switched to calonoff, stripdata.
• after about 17 strips i jumped to 0 dec offset (so we could see how well 45 amin handled getting off the moon.

• cband polB was having trouble with it's bias supply. This was causing the gain to jump around.
  
• hopefully it will be stable by 08apr19..
  
• Page1:
• top: strip total power ( in degK) vs strip offset
• I didn't bother to remove rfi.. the one crazy strip needed to have the rfi removed before computing total power.
• this was the 172.032 Mhz bw centered at 4300 Mhz.
  
• bottom: ra,dec offsets for each strip.
• In both plots you can see where i jumped to the center of the map.
• Page 2:
• top : time between strips
• 0-4 had the calonoff,datastrip,calonoff.. about 112 seconds/strips
• 6-16 were strips with  calonoff, datastrip. about 92 seconds

Summary:

• You probably want to do calonoff, datastrips rather than  calonoff,datastrip,calonoff
• 45 amin strips are not long enough to get a good baseline off of the moon (probably the sidelobes and the 100+ degK of the moon)
•