Index: trunk/magic/remove/src/streaksastrom.c
===================================================================
--- trunk/magic/remove/src/streaksastrom.c	(revision 20573)
+++ trunk/magic/remove/src/streaksastrom.c	(revision 20816)
@@ -150,2 +150,80 @@
 }
  
+static bool
+readAstrometry(streakFiles *sf)
+{
+    pmHDU *phu = pmFPAviewThisPHU(sf->view, sf->inAstrom->fpa);
+    if (phu) {
+        bool status;
+        char *ctype = psMetadataLookupStr(&status, phu->header, "CTYPE1");
+        if (ctype) {
+            sf->bilevelAstrometry = !strcmp (&ctype[4], "-DIS");
+        }
+    }
+
+    if (sf->bilevelAstrometry) {
+        // Do we get here for GPC1 ? I don't necessarily have an fpa for the input image
+        if (!pmAstromReadBilevelMosaic(sf->inAstrom->fpa, phu->header)) {
+            psError(PS_ERR_UNKNOWN, false, "Unable to read bilevel mosaic astrometry for input FPA.");
+            return false;
+        }
+    } else {
+        pmHDU *hdu = pmFPAviewThisHDU(sf->view, sf->inAstrom->fpa);
+        PS_ASSERT_PTR_NON_NULL(hdu, 1)
+        PS_ASSERT_PTR_NON_NULL(hdu->header, 1)
+
+        // we use a default FPA pixel scale of 1.0
+        if (!pmAstromReadWCS (sf->inAstrom->fpa, sf->chip, hdu->header, 1.0)) {
+            psError(PS_ERR_UNKNOWN, false, "Unable to read WCS astrometry for input FPA.");
+            return false;
+        }
+    }
+
+    return true;
+}
+
+void
+setupAstrometry(streakFiles *sf)
+{
+    bool status;
+    // load astrometry file
+    if (USE_SUPPLIED_ASTROM(sf->stage)) {
+        sf->inAstrom = pmFPAfileDefineFromArgs(&status, sf->config, "PSWARP.ASTROM", "ASTROM");
+    } else {
+        // otherwise get astrometry from pmfile
+        if (!sf->inImage->pmfile) {
+            streaksExit("unexpected null pmFPAfile", PS_EXIT_CONFIG_ERROR);
+        }
+        sf->inAstrom = sf->inImage->pmfile;
+    }
+    sf->view = pmFPAviewAlloc(0);
+
+    if (!pmFPAfileIOChecks(sf->config, sf->view, PM_FPA_BEFORE)) {
+        psError(PS_ERR_UNKNOWN, false, "Failed to load input.");
+        streaksExit("", PS_EXIT_DATA_ERROR);
+    }
+
+    while ((sf->chip = pmFPAviewNextChip(sf->view, sf->inAstrom->fpa, 1)))  {
+        if (sf->inAstrom->fpa->chips->n == 1) {
+            // There's only one chip in this FPA and we've got it so break
+            break;
+        }
+        bool status;
+        psString chip_name = psMetadataLookupStr(&status, sf->chip->concepts, "CHIP.NAME");
+        if (!strcmp(chip_name, sf->class_id)) {
+            break;
+        }
+    } 
+    if (!sf->chip) {
+        psError(PS_ERR_UNKNOWN, true, "Failed to find chip with data.");
+        streaksExit("", PS_EXIT_DATA_ERROR);
+    }
+    if (!pmFPAfileIOChecks(sf->config, sf->view, PM_FPA_BEFORE)) {
+        psError(PS_ERR_UNKNOWN, false, "failed to load chip");
+        streaksExit("", PS_EXIT_DATA_ERROR);
+    }
+    if (!readAstrometry(sf)) {
+        psError(PS_ERR_UNKNOWN, false, "failed to read astrometry");
+        streaksExit("", PS_EXIT_DATA_ERROR);
+    }
+}