How can I search for moving solar system targets in the PS1 images and catalogs?
See the How to search for moving targets in PS1 images and catalogs page for a Python Jupyter notebook that demonstrates one approach to searching the PS1 archive for either images or catalogs that have observations of solar system targets. A MAST interface is currently under development to make this kind of search easier.
How good is PS1 astrometry?
The times in the warp image headers and in the catalog (e.g., the
obsTime column in the Detection table) are defined using international atomic time (TAI) rather than UTC time. Those times differ by the addition of leap seconds, which leads to header times that differ by 34 or 35 seconds from the UTC times. (See Rots et al. 2015 for more details.) If you are concerned with timing at this level, you may need to convert the times to UTC. For the warp images, the fix for this is to insert the keyword
TIMESYS = 'TAI' in the header. FITS cutout images have a correct
TIMESYS keyword (as of 2022 January 20), but full skycell FITS images do not have a
TIMESYS keyword. For the database times, the fix is to subtract 34 or 35 seconds (depending on the date) from the TAI time to get the UTC time. The
astropy.Time module includes convenient functions for converting between TAI and UTC times.
Also note that the epoch given in the FITS header for the warp images is the start time of the observation, while the epoch in the database for
Detection entries is the mean time of the observation, which is the start time plus 15 seconds (since the exposure time for PS1 images is 30 seconds). So you should add 15 seconds to the warp header's
MJD-OBS keyword value to get the equivalent value from the
Detection.obsTime column in the PS1 database.