Welcome to apogeeql’s documentation!
This is the Sphinx documentation for the SDSS Python product apogeeql
apogeeql is the Python actor that runs at APO and LCO. It connects to the hub and is responsible for annotating APOGEE files with additional header information, copying them to the APOGEE computer, and triggering the quicklook and quickred IDL processes that process these files, including bundling them for archiving, calulating S/N, and adding information to the database. The apogeeql actor also produces versions of a plugmap file that connects the plPlugMapM information with H magnitudes from platedb; this is needed for the quicklook/quickred processing.
The apogeeql actor orchestrates APOGEE data taking at both APO and LCO. It interacts with the APOGEE instrument software, quicklook, quickred and the hub to handle the images that are taken. Once a read is finished the apogeeql actor “annotates” the FITS header with extra information, copies the annotated frame to a certain location on disk, and lets the quicklook know that a read is ready to be checked. At the beginning of an exposure the actor also reads in necessary information (plugmap, calibration data, etc.), creates a temporary plugmap file (plPlugMapA).
The actual reduction of the images is done by IDL routines referred to as quicklook and quickred. quicklook processes individual reads, while quickred processes individual exposures, i.e., after all reads have been completed. The IDL routines extract spectra, calculate S/N for each object, and calculate an overall plate S/N at a fiducial magnitude, using the magnitudes of each object from a plugmap file.
The communication between the Python actor and IDL is accomplished by linking several IDL processes to the actor when the actor is started. These bridge processes run the IDL commands apql_wrapper and apqr_wrapper. These set up some calibration files to be used for the processing. A few test commands and responses are then sent, and then the wrappers go into indefinite loops, waiting for commands from the apogeeql actor.
As the Python actor gets notifications from the hub about exposure and plate loading activity, it acts on these and, when necessary, passes information and/or commands to the IDL processes to do the processing.
quicklook is much more complicated than quickred because it returns information back to the actor to be sent to the hub. In practice, however, quicklook information has not really been used by the observers in SDSS-IV.
Specifically, notifications are acted upon as follows:
When the actor receives a pointingInfo notification, it gets the plugmap information and creates a plPlugMapA file for use by the IDL routines. It communicates this information to the IDL processes by sending:
plugMapInfo={plate},{scan_mjd},{scan_id},{filename}
to quicklook and quickred wrappers, who save the filename to be passed to the reduction routines.
When the actor receives an exposureState notification with a status of DONE, STOPPED, or FAILED, it sends:
UTR=DONE
to the quickred wrapper. The quickred wrapper in turns starts the reduction with:
apquickred,frameid,plugfile=plugfile,rawdir=rawdir,bundledir=bundledir,quickreddir=quickreddir,bpmid=bpmid,psfid=psfid,exp_pk=exp_pk,mjd5=mjd5,/NOWAIT
When the actor receives an exposureWroteFile notification, if it is the first read of an exposure, it creates a database entry and gets a primary key for the exposure. With every exposureWroteFile notification, it sends:
s.sendLine(‘UTR=%s,%d,%d,%d’ % (newfilename, Apogeeql.exp_pk, readnum, Apogeeql.numReadsCommanded))
to quicklook.
When the actor receives an exposureWroteSummary notification, it copies the summary-ICS file to the apogee computer.
to quicklook