Changeset 18011 for trunk/ppSim/notes.txt

Timestamp:

Jun 8, 2008, 4:03:31 PM (18 years ago)

Author:

eugene

Message:

update from changes on eam_branch_20080511 : adding photometry of fake sources, force photometry; major cleanups

File:

• trunk/ppSim/notes.txt (modified) (1 diff)

trunk/ppSim/notes.txt

@@ +1 @@
+
+
+2008.05.17
+
+  pmFPAfiles used in ppSim:
+
+  PPSIM.INPUT : an input image loaded by ppSim; the simulated features
+                may be added to this image.  In fact, the features are
+                generated in the output image, and the two images are
+                added (as images) together.
+
+  PPSIM.OUTPUT  : the output image.  this file is used for the main
+                  ppSimLoop function
+
+  PPSIM.CHIP    : chip-mosaiced version of the output image.  only
+                  generated if photometry is requested.  Is this
+                  actually used as an output image?
+
+  PPSIM.REAL.SOURCES : real sources loaded by PPSIM.  these sources
+                       are subtracted from the image before testing
+                       for the detectability of the fake sources and
+                       before measuring the flux of fake or forced
+                       soures.  They should be the sources measured in
+                       a previous psphot run, though any input list
+                       could be used.  Results are very ill-defined if
+                       the sources do not correspond to actual image
+                       sources!
+
+  PSPHOT.PSF.LOAD : input PSF model used to measure the input sources
+
+  PPSIM.SOURCES : output fake sources (injected fake sources with real values) 
+  PPSIM.FAKE.SOURCES : output fake photometry (measured photometry for all fake sources)
+  PPSIM.FORCE.SOURCES : output force photometry
+  
+  ** used within psphot functions:
+  PSPHOT.BACKMDL : model background generated by psphotModelBackground
+  PSPHOT.BACKMDL.STDEV : model background error generated by psphotModelBackground
+  PSPHOT.BACKGND : full-scale model background generated by psphotSubtractBackground
+  PSPHOT.BACKSUB : background-subtracted image
+
+2008.05.15
+
+  For fake and force photometry, we need to load the known existing
+  sources, then perform a complete linear fit solution to the complete
+  set of both real (known) sources plus the fake and/or forced
+  photometry positions (as PSFs).  The fake and forced photometry
+  positions need to be measured independently.  This provides the real
+  photometry for these sources ** in the presence of the other real
+  sources **.  In order to test the detectability of the fake sources
+  (or the forced sources, for that matter), we need to generate the
+  smoothed detection image, and determine the peak value at the
+  positions of the sources.  
+
+  ppSimPhotomReadout outline:
+
+  * we have three source lists (loaded before the function is called):
+    * realSources : these are loaded from a CMF-style file (or equiv)
+    * fakeSources : these are defined internally, and need a link from
+                    the input fake source to the measured fake source
+    * forceSources : these are loaded from a DVO database via getstar
+
+  * we require a supplied PSF
+
+  * need to subtract the background (before or after subtracting the
+    sources?)
+
+  * subtract the real sources
+  * model the background
+  * build the detection image
+  * measure the detectability of the fake and force sources
+  * replace the real sources
+
+  * merge real + fake sources
+  * linear fit to merged source list
+  * replace the sources (make 'no-subtract' option?)
+
+  * merge real + forced sources
+  * linear fit to merged source list
+  * replace the sources (make 'no-subtract' option?)
+
+
 
 ppSim development work still needed: