MOPS Detectability Query

MOPS will query the IPP regarding the detectability of hypothetical elongated detections specified using ($RA_0$, $Dec_0$, $Time_0$, $RA_1$, $Dec_1$, $Time_1$) tuples by submitting all information required to construct a FPA PSF at the time of the detections. It is the responsibility of MOPS to generate and manage unique query IDs.

A query should specify the stage of the processing pipeline to measure the detections. This is specified by the STAGE parameter, which has allowed values of chip,warp,stack, and diff.

All MOPS detectability queries will occur with respect to an already-ingested FPA transient detection list. The query being asked by MOPS is essentially whether a particular trail in an acquired FPA image was masked for any reason and to what degree. Thus the originating IPP FPA\_ID is required. A query may request data from a different processing stage than given by the transient detection list. Because of this, IPP stage id values may be used in place of the FPA\_ID.

MOPS will simulate elongated ('trailed') PSFs, relevant for fast-moving objects. Since some or all of a trail may be masked, MOPS will for all detections provide starting and ending RA and Dec. For most detections these two positions will be nearly coincident, appearing as a circular point-source PSF, but for fast-moving objects these positions may differ by many pixels in the FPA. The detectability server currently only supports point source detections, using the starting RA and Dec provided by the query.

In addition to the required BINTABLE extension header keywords described above, the FITS header for the detectability query shall include the following required keywords shown in table \ref{detquery-keywords}. The subsequent FITS table, with EXTNAME of MOPS_DETECTABILITY_QUERY, shall include columns whose definitions are listed in table \ref{detquery-table}.

MOPS-IPP Detectability Query Keywords\label{detquery-keywords}

Column	Precision	Description
QUERY_ID	char(20)	MOPS query ID for this batch query
FPA_ID	char(20)	original FPA_ID used at ingest
MJD-OBS	F64	starting time of the exposure, MJD
FILTER	char(3)	effective filter used for the exposure as a string, allowed values of g, r, i, z, y, B, V, w
OBSCODE	char(3)	site identifier (MPC observatory code)
STAGE	char(20)	stage name to perform query on, allowed values of 'chip', 'warp', 'stack', and 'diff'

MOPS-IPP Detectability Query Table Columns\label{detquery-table}

Column	Precision	Description
ROWNUM	char(20)	identifier for this row in the table
RA1_DEG	F64	coordinate at the start of exposure, in degrees
DEC1_DEG	F64	coordinate at the start of exposure, in degrees
RA2_DEG	F64	coordinate at the end of exposure, in degrees
DEC2_DEG	F64	coordinate at the end of exposure, in degrees
MAG	F64	apparent magnitude

EXTVER 2 Queries

If the EXTVER value has the value of 2, then the query parsing routine shall be more relaxed. The only required BINTABLE extension header keywords shall be EXTNAME (required value MOPS_DETECTABILITY_QUERY), EXTVER (required value 2 for this relaxed parsing), and a unique QUERY_ID. All other header keywords specified in \ref{detquery-keywords} are optional, and when specified, will be applied to all rows listed in the query. If a header keyword is not specified in the header, it may be included as a query table column. The only restriction shall be that each FPA_ID have a unique STAGE.

If a keyword is not specified, a default value shall be chosen by the detectability server as summarized in table \ref{detquery-defaults}. If multiple columns are unspecified, and cannot be calculated from the default values, the detectability server will return a PSTAMP_INVALID_REQUEST error.

MOPS-IPP Detectability Query EXTVER=2 Default Values\labe{detquery-defaults}

Column	Default value
STAGE	'diff'
OBSCODE	566
FILTER	Uniquely determined from requested FPA_ID
MJD-OBS	Uniquely determined from requested FPA_ID
FPA_ID	Calculated from FPA with requested FILTER and MJD-OBS containing requested RA1_DEG and DEC1_DEG

IPP Detectability Response

IPP will return a table listing the submitted query detections and a set of values $(N, f, flux)$ indicating the number of pixels relevant to the detection's PSF, the fraction of these pixels detectable by IPP, and the flux measured for the detection. The table will also note if an error occurred while processing the request specification by setting the ERROR_CODE for the detection to a non-zero value. The values for ERROR_CODE are listed in table \ref{pss-errorcodes}.

For infrequent cases where a trail may completely traverse a masked area (due to chip gap, streak removal, or similar), the response may be erroneous or incomplete. This error and its effects will be studied during PS-1 operations.

In addition to the required BINTABLE extension header keywords described above, the FITS header for the detectability response shall include the following required keywords shown in table \ref{detresponse-keywords}. The subsequent FITS table, with EXTNAME of MOPS_DETECTABILITY_RESPONSE, shall include columns whose definitions are listed in table \ref{detresponse-table}.

MOPS-IPP Detectability Response Keywords\label{detresponse-keywords}

Column	Precision	Description
QUERY_ID	char(20)	originating MOPS query ID
FPA_ID	char(20)	IPP FPA ID used in detectability request (EXTVER=1 only)

MOPS-IPP Detectability Response Table Columns\label{detresponse-table}

Column	Precision	Description
ROWNUM	char(20)	matching rownum from original request
ERROR_CODE	U32	Error code (see text)
DETECT_N	U32	number of pixels used in the hypothetical PSF for the query detection (CMF column name "PSF_NPIX")
DETECT_F	F64	detectability, indicating the fraction of PSF pixels detectable by IPP (CMF column name "PSF_QF")
TARGET_FLUX	F64	flux measured for the PSF fit for the query detection (CMF column name "PSF_INST_FLUX")
TARGET_FLUX_SIG	F64	error in flux measurement (CMF column name "PSF_INST_FLUX_SIG")
FPA_ID	char(20)	IPP FPA ID used in detectability request (EXTVER=2 only)

Postage Stamp Error Codes \label{pss-errorcodes}

Name	ERROR_CODE value	Description
PSTAMP_SUCCESS	0	No errors
PSTAMP_SYSTEM_ERROR	10	Some unspecified system error occurred during processing
PSTAMP_NOT_IMPLEMENTED	11	Feature not yet implemented
PSTAMP_UNKNOWN_ERROR	12	Unknown error
PSTAMP_DUP_REQUEST	20	Request name is a duplicate
PSTAMP_INVALID_REQUEST	21	Error in request specification. See parse_error.txt
PSTAMP_UNKNOWN_PRODUCT	22	Unknown product in request specification
PSTAMP_NO_IMAGE_MATCH	23	No images matched the request
PSTAMP_NOT_DESTREAKED	24	Image matched, but not yet destreaked
PSTAMP_NOT_AVAILABLE	25	Image not available (temporary)
PSTAMP_GONE	26	Image is no longer available
PSTAMP_NO_JOBS_QUEUED	27	Request specification yielded no jobs. See parse_error.txt
PSTAMP_NO_OVERLAP	28	Center not contained in any image of interest