Index: /trunk/pstamp/scripts/detect_query_read
===================================================================
--- /trunk/pstamp/scripts/detect_query_read	(revision 33283)
+++ /trunk/pstamp/scripts/detect_query_read	(revision 33284)
@@ -222,6 +222,7 @@
     if (($colData{FPA_ID}[$i] eq "Not_Set")&&(($colData{'FILTER'}[$i] ne "Not_Set")&&
 					      ($colData{'MJD-OBS'}[$i] ne "Not_Set"))) {
-	my $dateobs_begin = mjd_to_dateobs($colData{'MJD-OBS'}[$i]);
-	my $dateobs_end = mjd_to_dateobs($colData{'MJD-OBS'}[$i] + 1);
+        my $mjd_obs = int $colData{'MJD-OBS'}[$i];
+	my $dateobs_begin = mjd_to_dateobs($mjd_obs);
+	my $dateobs_end = mjd_to_dateobs($mjd_obs + 1);
 	my $ra = $colData{'RA1_DEG'}[$i];
 	my $dec = $colData{'DEC1_DEG'}[$i];
@@ -229,7 +230,13 @@
 	my $cmd;
 	if ($colData{STAGE}[$i] eq 'SSdiff') {
-	    $cmd = "$difftool -listrun -dbname $dbname -filter $filter ";
-	    $cmd .= " -dateobs_begin $dateobs_begin -dateobs_end $dateobs_end ";
-	    $cmd .= " -ra $ra -decl $dec -radius 1.5 -limit 1 -diff_mode 4";
+            # Assumption: All Stack Stack diffs are for a medium deep field
+            # go find which one the coordinates are in
+            # XXX: If we don't find one we'll just get the first SSdiff
+            # in the filter on the day in question
+            my $field = find_md_field($ra, $dec, 1.6);
+	    $cmd = "$difftool -listssrun -dbname $dbname -filter $filter ";
+	    $cmd .= " -mjd_obs_begin $mjd_obs -mjd_obs_end " . (1 + $mjd_obs);
+	    $cmd .= " -limit 1";
+            $cmd .= " -tess_id $field%" if $field;
 	}
 	elsif ($colData{STAGE}[$i] eq 'WSdiff') {
@@ -366,3 +373,35 @@
 
 
+# Given an RA and  DEC return the MD field that contains it if any.
+# This is much faster than actuallly examining the tessellation
+# using dvoImagesAtCoords
+
+sub find_md_field {
+    my $ra_deg = shift;
+    my $dec_deg = shift;
+    my $radius_deg = shift;
+
+    my @MD     = qw(MD01  MD02    MD03     MD04      MD05    MD06      MD07    MD08    MD09     MD10);
+    my @MD_RA  = (35.875, 53.10, 130.592, 150.000, 161.917, 185.000, 213.454, 242.787, 333.98, 352.312);
+    my @MD_DEC = (-4.25,  -27.8,   44.317,   2.20,   58.083,  47.117,  53.243, 54.95,    0.283, -0.433);
+    my $PS_DEG_RAD = 0.017453292519943;
+
+    my $ra     = $ra_deg * $PS_DEG_RAD;
+    my $dec    = $dec_deg * $PS_DEG_RAD;
+    my $radius = $radius_deg * $PS_DEG_RAD;
+
+    for (my $i = 0; $i < scalar @MD; $i++) {
+        
+        my $dist = acos((cos($PS_DEG_RAD * $MD_DEC[$i]) * cos($dec) * cos($PS_DEG_RAD * $MD_RA[$i] - $ra)) +(sin($PS_DEG_RAD * $MD_DEC[$i]) * sin($dec)));
+
+        if ($dist < $radius) {
+            return $MD[$i];
+        }
+    }
+    print STDERR "failed to find MD field containing $ra_deg $dec_deg\n";
+
+    return undef;
+}
+
+
 __END__