Calibrations

Sky dip at start of each run
Load curve 4 times per day
"Row-cal" 4 times per day - scan each row of array across source (RCW38)
Monitor beam width and abs cal
"Cross-obs" 4 times per day - scan center feed az/el across source
Monitor pointing offset
"Cal-source" every 7(30) minutes - flip down mirror and rotate grid
Monitor instrument gain stability
"El-nod" every 7(30) minutes - small el scan to inject atmos. ramp
Measure A/B and feed-feed relative gain with beam filling source