Changeset 17705 for branches/eam_branch_20080511/ppSim/src/ppSimMakeSky.c

Timestamp:

May 15, 2008, 4:44:46 PM (18 years ago)

Author:

eugene

Message:

options to turn on and off all of the components

File:

• branches/eam_branch_20080511/ppSim/src/ppSimMakeSky.c (modified) (4 diffs)

branches/eam_branch_20080511/ppSim/src/ppSimMakeSky.c

@@ -17 +17 @@
     psMetadata *recipe = psMetadataLookupMetadata(&status, config->recipes, PPSIM_RECIPE); // Recipe
 
-    bool sky = psMetadataLookupBool(&status, recipe, "SKY"); // Generate a SKY flux?
+    bool sky  = psMetadataLookupBool(&status, recipe, "SKY"); // Generate a SKY flux?
+    bool flat = psMetadataLookupBool(&status, recipe, "FLAT"); // Apply flat-field term?
  
     float expTime      = psMetadataLookupF32(&status, recipe, "EXPTIME"); // Exposure time
@@ -24 +25 @@
     float flatRate     = psMetadataLookupF32(&status, recipe, "FLAT.RATE"); // Flat-field rate
     float shutterTime  = psMetadataLookupF32(&status, recipe, "SHUTTER.TIME"); // Shutter time
-    float scatterScale = psMetadataLookupF32(&status, recipe, "SCATTER.SCALE"); // scattered light term
+    float scatterFrac  = psMetadataLookupF32(&status, recipe, "SCATTER.FRAC"); // scattered light fraction (max)
     float skyRate      = psMetadataLookupF32(&status, recipe, "SKY.RATE"); // Sky rate
-    if (isnan(skyRate)) {
+    float skyMags      = psMetadataLookupF32(&status, recipe, "SKY.MAGS");  assert (status);
+    if (!isnan(skyMags)) {
         float zp       = psMetadataLookupF32(&status, recipe, "ZEROPOINT"); assert (status);
         float scale    = psMetadataLookupF32(&status, recipe, "PIXEL.SCALE"); assert (status);
-        float skyMags  = psMetadataLookupF32(&status, recipe, "SKY.MAGS");  assert (status);
         skyRate = scale * scale * ppSimMagToFlux (skyMags, zp);
     }
@@ -69 +70 @@
             float realExpTime = expTime + shutterTime * (xFPA + yFPA + 2.0) / 4.0;
 
-            // Gaussian flat-field over the FPA
-            float flatValue = expf(-0.5 / PS_SQR(flatSigma) * (PS_SQR(yFPA) + PS_SQR(xFPA))) / flatSigma / sqrtf(2.0 * M_PI);
+            // Gaussian flat-field over the FPA with flatValue = 1.0 at the field center
+            float flatValue = 1.0;
+            if (flat) {
+                // we make the flat-field have a response of 1.0 at the field center (like a vignetting)
+                flatValue = expf(-0.5 / PS_SQR(flatSigma) * (PS_SQR(yFPA) + PS_SQR(xFPA)));
+            }
 
             float scatterRate = 0.0;
@@ -78 +83 @@
               if (type == PPSIM_TYPE_FLAT) {
                 float xF = 2.0*(xFPA / dXfpa) - 1.0;
-                scatterRate = scatterScale * PS_SQR(xF);
+                scatterRate = scatterFrac * PS_SQR(xF);
               }
 
               // Sky background
-              float skyFlux = (skyRate * flatValue + scatterRate) * realExpTime; // Flux from sky
+              float skyFlux = (skyRate * (flatValue + scatterRate)) * realExpTime; // Flux from sky
               signal->data.F32[y][x] += skyFlux;
               variance->data.F32[y][x] += skyFlux;