Select data from database

What you will learn

You will learn how to select COMPTEL data for an analysis with ctools.

The first step of a COMPTEL science analysis consists in the selection of the relevant viewing periods. You do this with the comobsselect script. In the following example, all viewing periods with pointing directions within 30 degrees of the Crab and with dates between April and May 1991 are selected.

$ comobsselect
Pointing selection region shape (CIRCLE|BOX) [CIRCLE]
Coordinate system (CEL - celestial, GAL - galactic) (CEL|GAL) [GAL]
Galactic longitude of selection centre (deg) (0-360) [184.56]
Galactic latitude of selection centre (deg) (-90-90) [-5.79]
Radius of selection circle (deg) (0-180) [30]
Start time (UTC string, JD, MJD or MET in seconds) [NONE] 1991-05-01T00:00:00
Stop time (UTC string, JD, MJD or MET in seconds) [NONE] 1991-06-01T00:00:00
Output observation definition file [obs.xml]

Giving the limits on the start and stop time, only viewing period 0001 will be selected by comobsselect. The resulting observation definition file obs.xml will have the following content:

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<observation_list title="observation list">
  <observation name="CRAB" id="vp0001_0" instrument="COM">
    <parameter name="EVP" file="$COMDATA/phase01/vp0001_0/m28511_evp.fits" />
    <parameter name="TIM" file="$COMDATA/dbase/tim/vp0001_0_tim.fits" />
    <parameter name="OAD" file="$COMDATA/phase01/vp0001_0/m20037_oad.fits" />
    <parameter name="OAD" file="$COMDATA/phase01/vp0001_0/m20039_oad.fits" />
    <parameter name="OAD" file="$COMDATA/phase01/vp0001_0/m20041_oad.fits" />
    <parameter name="OAD" file="$COMDATA/phase01/vp0001_0/m20045_oad.fits" />
    <parameter name="OAD" file="$COMDATA/phase01/vp0001_0/m20048_oad.fits" />
    <parameter name="OAD" file="$COMDATA/phase01/vp0001_0/m20050_oad.fits" />
    <parameter name="OAD" file="$COMDATA/phase01/vp0001_0/m20054_oad.fits" />
    <parameter name="OAD" file="$COMDATA/phase01/vp0001_0/m20058_oad.fits" />
    <parameter name="OAD" file="$COMDATA/phase01/vp0001_0/m20064_oad.fits" />
    <parameter name="OAD" file="$COMDATA/phase01/vp0001_0/m20066_oad.fits" />
    <parameter name="OAD" file="$COMDATA/phase01/vp0001_0/m20068_oad.fits" />
    <parameter name="OAD" file="$COMDATA/phase01/vp0001_0/m20071_oad.fits" />
    <parameter name="OAD" file="$COMDATA/phase01/vp0001_0/m20073_oad.fits" />
    <parameter name="OAD" file="$COMDATA/phase01/vp0001_0/m20078_oad.fits" />
    <parameter name="OAD" file="$COMDATA/phase01/vp0001_0/m20081_oad.fits" />
  </observation>
</observation_list>

The file contains a single observation, composed of an event file (EVP), a Good Time Interval file (TIM) and 15 Orbit Aspect data files (OAD).

Note

If no limit on the observation dates should be applied then specify NONE as the start or stop time.