[daip] Re: question about SMOTH

[Eric Greisen]

Pat Palmer writes:

To generate a more formal reply

 > SMOTH is the task I ran that said:
 > 
 > SMOTH1: Task SMOTH  (release of 31DEC02) begins
 > SMOTH1: YOU ARE USING A VERY NON-STANDARD TASK
 > SMOTH1: IT IS DESIGNED TO WORK ONLY ON VAXES
 > SMOTH1: VERSION 2.3  -  23 JANUARY 1984

    I dropped some of this verbiage...

 > 
 > The only anomaly is that the rms went up (1.79 mJy vs. 1.18) when I
 > convolved to a beam with about 6 times the area.  The peak went up
 > also (26.8 mJy vs 8.72), so the signal-to-noise went up, as it should
 > have.  (The beam are in pixels according to IMEAN is what I think it
 > should be.)

    The rms in Jy/beam goes up some as the beam area goes up even
more.  That is normal and correct.

 > 

 >    300  SMOTH  BMAJ=  0.4285 BMIN=  0.3973 BPA=  76.6 / Input beam

 >    314  AIPS   CLEAN BMAJ=  2.7778E-04 BMIN=  2.7778E-04 BPA=   0.00

 > 
 > My questions are: why did the rms go up, and what is that strange
 > value for the beam (although it doesn't seem to cause any problem, I
 > am curious).
 > 
The units are degrees when AIPS FITTP adds the AIPS CLEAN beam.

Eric Greisen