Changeset 31927 for branches/eam_branches/ipp-20110710/psModules/src/objects/pmSourceOutputs.c

Timestamp:

Jul 22, 2011, 5:10:58 PM (15 years ago)

Author:

eugene

Message:

switch to consolidated, autocoded pmSourceIO_CMF files

File:

• branches/eam_branches/ipp-20110710/psModules/src/objects/pmSourceOutputs.c (modified) (1 diff)

branches/eam_branches/ipp-20110710/psModules/src/objects/pmSourceOutputs.c

@@ -181 +181 @@
     return true;
 }
+
+bool pmSourceLocalAstrometry (psSphere *ptSky, float *posAngle, float *pltScale, pmChip *chip, float xPos, float yPos) {
+
+    pmFPA *fpa = chip->parent;
+
+    if (!chip->toFPA) goto escape;
+    if (!fpa->toTPA) goto escape;
+    if (!fpa->toSky) goto escape;
+
+    // generate RA,DEC
+    psPlane ptCH, ptFP, ptTP_o, ptTP_x, ptTP_y;
+
+    // calculate the astrometry for the coordinate of interest
+    ptCH.x = xPos;
+    ptCH.y = yPos;
+    psPlaneTransformApply (&ptFP, chip->toFPA, &ptCH);
+    psPlaneTransformApply (&ptTP_o, fpa->toTPA, &ptFP);
+    psDeproject (ptSky, &ptTP_o, fpa->toSky);
+
+    // calculate the astrometry for the coordinate + 1pix in X
+    ptCH.x = xPos + 1.0;
+    ptCH.y = yPos;
+    psPlaneTransformApply (&ptFP, chip->toFPA, &ptCH);
+    psPlaneTransformApply (&ptTP_x, fpa->toTPA, &ptFP);
+
+    // calculate the astrometry for the coordinate + 1pix in Y
+    ptCH.x = xPos;
+    ptCH.y = yPos + 1.0;
+    psPlaneTransformApply (&ptFP, chip->toFPA, &ptCH);
+    psPlaneTransformApply (&ptTP_y, fpa->toTPA, &ptFP);
+
+    // the resulting Tangent Plane coordinates are in TP pixels; convert to local Tangent Plane
+    // degrees
+
+    float dTPx_dCHx = fpa->toSky->Xs * (ptTP_x.x - ptTP_o.x);
+    float dTPy_dCHx = fpa->toSky->Ys * (ptTP_x.y - ptTP_o.y);
+
+    float dTPx_dCHy = fpa->toSky->Xs * (ptTP_y.x - ptTP_o.x);
+    float dTPy_dCHy = fpa->toSky->Ys * (ptTP_y.y - ptTP_o.y);
+
+    float pltScale_x = hypot(dTPx_dCHx, dTPy_dCHx);
+    float pltScale_y = hypot(dTPx_dCHy, dTPy_dCHy);
+    *pltScale = 0.5*(pltScale_x + pltScale_y);
+
+    float posAngle_x = atan2 (+dTPy_dCHx, +dTPx_dCHx);
+    float posAngle_y = atan2 (-dTPy_dCHy, +dTPx_dCHy);
+    *posAngle = 0.5*(posAngle_x + posAngle_y);
+
+    return true;
+
+escape:
+    // no astrometry calibration, give up
+    ptSky->r = NAN;
+    ptSky->d = NAN;
+    *posAngle = NAN;
+    *pltScale = NAN;
+
+    return false;
+}
+