Index: /branches/eam_branches/ipp-20100621/Ohana/src/opihi/cmd.astro/cgrid.c
===================================================================
--- /branches/eam_branches/ipp-20100621/Ohana/src/opihi/cmd.astro/cgrid.c	(revision 28762)
+++ /branches/eam_branches/ipp-20100621/Ohana/src/opihi/cmd.astro/cgrid.c	(revision 28763)
@@ -153,4 +153,12 @@
   SetVector (&Yvec, OPIHI_FLT, NELEMENTS);
   
+  { // sanity check
+    float Nelem;
+    Nelem = (lastRA - firstRA) / minorRA;
+    if (!isfinite(Nelem) || (fabs(Nelem) > 10000)) { fprintf (stderr, "absurd cgrid range %f to %f in steps of %f\n", firstRA, lastRA, minorRA); return FALSE; }
+    Nelem = (lastDEC - firstDEC) / minorDEC;
+    if (!isfinite(Nelem) || (fabs(Nelem) > 10000)) { fprintf (stderr, "absurd cgrid range %f to %f in steps of %f\n", firstDEC, lastDEC, minorDEC); return FALSE; }
+  }
+
   /***  do consecutive RA lines, first increasing **/
   OnPic = TRUE;