Some notes for IRAC photometry: ------------------------------------- The name for the images should be kept to 13 letters of less (not counting .fits). Otherwise, it may confuse the ppp directory. ------------------------------------------- To use the .pppin file for object finding, one needs to enter the sky adu values for the ch1 and ch2. This can be found interactively within ppp. # rdis 1 231953irac1 rdis 2 231953irac1 # find an area on the image which is relatively blank, and # record its lower and upper corner I and J co-ordinates. # these are used to definte a "box" from which statistics are # computed. Should find area common to both channels so you # only have to do it once # set up a box boxe 1 I1 J1 I2 J2 # now compute the statistics of the pixel values # use the mode as the sky value #chanel 1 pmode 1 #chanel 2 pmode 2 # enter the sky values of each frame into the following # commands in the ofName.pppin script; supposed the # values of the sky are 61 and 74 for images 1 and 2 # carm 1 -61 # 3 #carm 2 -74 # 4 .................... edit the ofName.pppin file to have the correct sky values for the 2 images, and the correct names (best to do a global replace of the "telephone number" run the ofName.pppin script as a batch job run the 4 photometry scripts after editing the names in each. Note: The whole process can be automated if one creates a program that generate these scripts automatically, and a linux script to run each ppp script (in sequence).