Check for any bad flags

[martinjohndyer]

We recently had a few Swift alerts that were from a known source, and were only sent out because the satellite had lost tracking.

The GCN VOEvent is below. Note there are flags for StarTrack_Lost_Lock and Target_in_Gnd_Catalog that are both set to true for this event. I'm sure there are similar flags in Fermi GCNs.

<?xml version = \'1.0\' encoding = \'UTF-8\'?>
<voe:VOEvent
      ivorn="ivo://nasa.gsfc.gcn/SWIFT#BAT_GRB_Pos_972030-748"
      role="observation" version="2.0"
      xmlns:voe="http://www.ivoa.net/xml/VOEvent/v2.0"
      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      xsi:schemaLocation="http://www.ivoa.net/xml/VOEvent/v2.0  http://www.ivoa.net/xml/VOEvent/VOEvent-v2.0.xsd" >
  <Who>
    <AuthorIVORN>ivo://nasa.gsfc.tan/gcn</AuthorIVORN>
    <Author>
      <shortName>VO-GCN</shortName>
      <contactName>Scott Barthelmy</contactName>
      <contactPhone>+1-301-286-3106</contactPhone>
      <contactEmail>[email protected]</contactEmail>
    </Author>
    <Date>2020-05-13T14:56:44</Date>
    <Description>This VOEvent message was created with GCN VOE version: 1.47 08mar20</Description>
  </Who>
  <What>
    <Param name="Packet_Type"  value="61" />
    <Param name="Pkt_Ser_Num"  value="14" />
    <Param name="TrigID"       value="972030" ucd="meta.id" />
    <Param name="Segment_Num"  value="0" ucd="meta.id.part" />
    <Param name="Burst_TJD"    value="18982" unit="days" ucd="time" />
    <Param name="Burst_SOD"    value="53727.06" unit="sec" ucd="time" />
    <Param name="Burst_Inten"  value="0" unit="cts" ucd="phot.count;em.gamma.soft" />
    <Param name="Burst_Peak"   value="2632" unit="cts" ucd="phot.count;em.gamma.soft" />
    <Param name="Integ_Time"   value="64.000" unit="sec" ucd="time.interval" />
    <Param name="Phi"          value="88.81" unit="deg" ucd="pos.az.azi" />
    <Param name="Theta"        value="25.83" unit="deg" ucd="pos.az.zd" />
    <Param name="Trig_Index"   value="20000" />
    <Param name="Soln_Status"  value="0x513" />
    <Param name="Misc_flags"   value="0x200000" />
    <Param name="Cat_Num"      value="0" />
    <Param name="Rate_Signif"  value="0.00" unit="sigma" ucd="stat.snr" />
    <Param name="Image_Signif" value="12.32" unit="sigma" ucd="stat.snr" />
    <Param name="Bkg_Inten"    value="0" unit="cts" ucd="phot.count" />
    <Param name="Bkg_Time"     value="00:00:00.00" ucd="time.start" />
    <Param name="Bkg_Dur"      value="0.00" unit="sec" ucd="time.duration" />
    <Param name="SC_Long"      value="129.71" unit="deg" ucd="pos.earth.lon" />
    <Param name="SC_Lat"        value="-14.21" unit="deg" ucd="pos.earth.lat" />
    <Group name="Merit_Values" >
      <Param name="Merit_Val0" value="1" unit="dn" />
      <Param name="Merit_Val1" value="0" unit="dn" />
      <Param name="Merit_Val2" value="0" unit="dn" />
      <Param name="Merit_Val3" value="6" unit="dn" />
      <Param name="Merit_Val4" value="1" unit="dn" />
      <Param name="Merit_Val5" value="2" unit="dn" />
      <Param name="Merit_Val6" value="0" unit="dn" />
      <Param name="Merit_Val7" value="0" unit="dn" />
      <Param name="Merit_Val8" value="96" unit="dn" />
      <Param name="Merit_Val9" value="0" unit="dn" />
    </Group>
    <Group name="Solution_Status" >
      <Param name="Point_Source"             value="true" />
      <Param name="GRB_Identified"           value="true" />
      <Param name="Target_of_Interest"       value="false" />
      <Param name="Target_Imag_Trig"         value="true" />
      <Param name="Target_Rate_Trig"         value="false" />
      <Param name="Def_NOT_a_GRB"            value="false" />
      <Param name="Hi_Bkg_Level"             value="false" />
      <Param name="Neg_Bkg_Slope"            value="false" />
      <Param name="Lo_Image_Signif"          value="false" />
      <Param name="VERY_Lo_Image_Signif"     value="false" />
      <Param name="Target_in_Flt_Catalog"    value="false" />
      <Param name="Target_in_Gnd_Catalog"    value="true" />
      <Param name="Target_in_Blk_Catalog"    value="false" />
      <Param name="StarTrack_Lost_Lock"      value="true" />
      <Param name="Near_Bright_Star"         value="false" />
      <Param name="Src_Removed_from_OnBoard" value="false" />
      <Param name="Converted_SubThresh"      value="false" />
      <Param name="Spatial_Prox_Match"       value="false" />
      <Param name="Temporal_Prox_Match"      value="false" />
      <Param name="Test_Submission"          value="false" />
    </Group>
    <Group name="Misc_Flags" >
      <Param name="Values_Out_of_Range"        value="false" />
      <Param name="Already_Observing_Position" value="false" />
      <Param name="Near_Bright_Star"           value="false" />
      <Param name="Err_Circle_in_Galaxy"       value="false" />
      <Param name="Galaxy_in_Err_Circle"       value="false" />
      <Param name="ImTrig_during_ST_LoL"       value="true" />
      <Param name="TOO_Generated"              value="false" />
      <Param name="Trig_time_is_SecHdrTime"    value="false" />
      <Param name="Delayed_Transmission"       value="false" />
      <Param name="Updated_Notice"             value="false" />
      <Param name="Flt_Generated"              value="true" />
      <Param name="Gnd_Generated"              value="false" />
      <Param name="SERS_Generated"             value="false" />
      <Param name="Other_Generated"            value="false" />
      <Param name="CRC_Error"                  value="false" />
    </Group>
    <Param name="Coords_Type"   value="1" unit="dn" />
    <Param name="Coords_String" value="source_object" />
    <Group name="Obs_Support_Info" >
      <Description>The Sun and Moon values are valid at the time the VOEvent XML message was created.</Description>
      <Param name="Sun_RA"        value="50.91" unit="deg" ucd="pos.eq.ra" />
      <Param name="Sun_Dec"       value="18.60" unit="deg" ucd="pos.eq.dec" />
      <Param name="Sun_Distance"  value="165.84" unit="deg" ucd="pos.angDistance" />
      <Param name="Sun_Hr_Angle"  value="11.03" unit="hr" />
      <Param name="Moon_RA"       value="315.89" unit="deg" ucd="pos.eq.ra" />
      <Param name="Moon_Dec"      value="-20.45" unit="deg" ucd="pos.eq.dec" />
      <Param name="MOON_Distance" value="66.61" unit="deg" ucd="pos.angDistance" />
      <Param name="Moon_Illum"    value="59.51" unit="%" ucd="arith.ratio" />
      <Param name="Galactic_Long" value="359.13" unit="deg" ucd="pos.galactic.lon" />
      <Param name="Galactic_Lat"  value="23.58" unit="deg" ucd="pos.galactic.lat" />
      <Param name="Ecliptic_Long" value="246.03" unit="deg" ucd="pos.ecliptic.lon" />
      <Param name="Ecliptic_Lat"  value="5.65" unit="deg" ucd="pos.ecliptic.lat" />
    </Group>
    <Description>Type=61: The Swift-BAT instrument position notice.</Description>
  </What>
  <WhereWhen>
    <ObsDataLocation>
      <ObservatoryLocation id="GEOLUN" />
      <ObservationLocation>
        <AstroCoordSystem id="UTC-FK5-GEO" />
        <AstroCoords coord_system_id="UTC-FK5-GEO">
          <Time unit="s">
            <TimeInstant>
              <ISOTime>2020-05-13T14:55:27.06</ISOTime>
            </TimeInstant>
          </Time>
          <Position2D unit="deg">
            <Name1>RA</Name1>
            <Name2>Dec</Name2>
            <Value2>
              <C1>245.1629</C1>
              <C2>-15.7459</C2>
            </Value2>
            <Error2Radius>0.0500</Error2Radius>
          </Position2D>
        </AstroCoords>
      </ObservationLocation>
    </ObsDataLocation>
  <Description>The RA,Dec coordinates are of the type: source_object.</Description>
  </WhereWhen>
  <How>
    <Description>Swift Satellite, BAT Instrument</Description>
    <Reference uri="http://gcn.gsfc.nasa.gov/swift.html" type="url" />
  </How>
  <Why importance="0.90">
    <Inference probability="0.90">
      <Name>GRB 200513</Name>
      <Concept>process.variation.burst;em.gamma</Concept>
    </Inference>
  </Why>
  <Description>
  </Description>
</voe:VOEvent>

[martinjohndyer]

This is very much linked to #16, in that there are plenty of flags in the GCNs that we currently ignore. Note Target_in_Gnd_Catalog was true for the case given there too, so that would be a nice starting point.