The following program is carried out in order to consolidate the PHT 
calibration of chopped measurements and derive signal losses due to the high 
chopper frequency compared to signal stabilization time.

- observation of NGC628: background and star staring plus chopped measurements.


Several filters are taken to have several contrast levels between background
and source. The measurement includes staring and chopped observations  


.HISTORY
23/06/97        JA First version. Standard star is HR5340
26/08/97        JA Standard star is HR6705  
09/09/97        JA New version for NGC6543 (c200)
18/11/97        JA New version for IC 5201 (C100 & C200)
03/12/97        JA New version for NGC628 (C200: 120,135 and 200um)

.OTT 2639 
.TDT 2179