IPP to PSPS interface: ippToPsps

Links

​Datastore test area for PSPS

Introduction

ippToPsps is the interface between IPP and PSPS. In short, ippToPsps creates FITS files from data found in IPP smf and cmf files, as well as relevant DVO databases, then publishes them to a datastore in the form of jobs. On the PSPS side, the DXLayer polls the datastore, collects jobs when they become available, then converts the contents to csv files before sending them on to special MSSQL loader software, which inserts them into the PSPS database. Ultimately there will be feedback from PSPS regarding errors in the received data, to which ippToPsps will need to respond.

It is intended that the binary tables in the FITS files generated by ippToPsps will match the PSPS database schemas perfectly, the consequence being that any alterations to the PSPS database schema will only affect ippToPsps code, and not the DXLayer. A certain amount of data validation will be performed by ippToPsps before publication.

Architecture

ippToPsps

ippToPsps is a C program within the IPP build. When given the correct arguments it will generate a single FITS for the specified product (above). The program is run from a perl script, which itself generates a list of exposure IDs based on arguments provided by the user (label etc). An instance of ippToPsps is run per exposure ID.

Configuration

ippToPsps uses XML configuration files, as this affords the most flexibility.

FITS table shapes

XML files detailing PSPS database tables are used to automatically generate equivalent FITS tables. Because the PSPS schema can change, and we want to avoid code changes as much as possible, these XML files are created using a script (pspsSchema2xml.pl), so that whenever the schema changes, new configs can easily be created. The table shape configs are:

tables_init.xml
tables_detection.xml
tables_diff.xml
tables_stack.xml

FITS table contents

Most data to be loaded into the FITS tables comes from smf files. For many columns, there is a direct mapping between the the smf and the PSPS database column. These mappings are held, in XML format, in ...

The initialisation batch contains metadata that describes valid contents for the other batch types. Because these values may also change, these are held in an editable XML file as...

DXLayer

...

Loader

...

Products

ippToPsps creates three products.

• Detections
• Diffs
• Stacks

Detections

Input

Input is one IPP camera-stage smf file for a given exposure and an associated DVO database from which to retrieve object, and other, IDs.

Output

A FITS output file is generated with the following extensions:

1 Primary extension

1 FrameMeta extension

1 ImageMeta extension per chip

1 Detection extension per chip

So, 122 extensions in all, included the obligatory primary header.

Validation

Some validation is performed to aid the data's insertion into the PSPS database.

Diffs

Input

A set of cmf files, one for each skycell covered by a particular exposure.

Output

A FITS output file is generated with the following extensions:

...

Validation

Unresolved fields

Below are tables detailing which fields in the PSPS FITS files are still not populated by ippToPsps.

Unresolved fields for camera stage ('detections')

FrameMeta

PSPS field	PSPS type	PSPS Description	IPP source	Comments
analysisVer	SMALLINT	version number of analysis		pending
p1Recip	SMALLINT	IPP phase 1 recipe ID		pending
p2Recip	SMALLINT	IPP phase 2 recipe ID		pending
p3Recip	SMALLINT	IPP phase 3 recipe ID		pending
nAstRef	INT	number of astrometric reference sources		have values per chip, but global?
nPhoRef	INT	number of photometric reference sources		have values per chip, but global?

ImageMeta

PSPS field	PSPS type	PSPS Description	IPP source	Comments
bias	REAL	detector bias level		pending
biasScat	REAL	scatter in bias level		pending
photoScat	REAL	photometric scatter for chip	-999 for now
nPhoRef	INT	number of photometric reference sources	-999 for now
psfModelID	INT	PSF model identifier		pending
qaFlags	INT	Q/A flags		Get from DVO...

Detection

PSPS field	PSPS type	PSPS Description	IPP source	Comments
psfLikelihood	REAL	PSF likelihood	???

Unresolved fields for diff stage ('objects')

StackMeta

PSPS field	PSPS type	PSPS Description	IPP source	Comments
stackMetaID	BIGINT	stack identifier
skycellID	INT	skycell region identifier		missing from cmf files
surveyID	TINYINT	survey flag identifier		e.g. 3PI, M31, MD, STS - need common enum
photoCalID	INT	photometry code numerical id
filterID	TINYINT	filter identifier		IPP uses string (g.00000). Need enum.
stackTypeID	TINYINT	stack type identifier
refImageID	BIGINT	identifier of image used as reference for analysis
subtrImageID	BIGINT	identifier of image subtracted to generate difference image
analVer	SMALLINT	analysis version index
nP2Images	SMALLINT	number of P2 images contributing to this cell
astroScat	FLOAT	0.astrometric scatter for chip
photoScat	FLOAT	0.photometric scatter for chip
nAstroRef	INT	number of astrometric reference sources
nPhoRef	INT	number of photometric reference sources
psfFwhm	FLOAT	PSF full width at half maximum
psfmodelID	SMALLINT	PSF model identifier
psfExtra1	FLOAT	PSF parameters
psfExtra2	FLOAT	PSF parameters
photoZero	FLOAT	local derived photometric zero point
photoColor	FLOAT	local derived photometric color term
polyOrder	TINYINT	polynomial order of astrometry fit
pca1x3y0	FLOAT	polynomial coefficients for the astrometric fit		not available
pca1x2y1	FLOAT	polynomial coefficients for the astrometric fit		not available
pca1x1y2	FLOAT	polynomial coefficients for the astrometric fit		not available
pca1x0y3	FLOAT	polynomial coefficients for the astrometric fit		not available
pca1x2y0	FLOAT	polynomial coefficients for the astrometric fit		not available
pca1x1y1	FLOAT	polynomial coefficients for the astrometric fit		not available
pca1x0y2	FLOAT	polynomial coefficients for the astrometric fit		not available
pca2x3y0	FLOAT	polynomial coefficients for the astrometric fit		not available
pca2x2y1	FLOAT	polynomial coefficients for the astrometric fit		not available
pca2x1y2	FLOAT	polynomial coefficients for the astrometric fit		not available
pca2x0y3	FLOAT	polynomial coefficients for the astrometric fit		not available
pca2x2y0	FLOAT	polynomial coefficients for the astrometric fit		not available
pca2x1y1	FLOAT	polynomial coefficients for the astrometric fit		not available
pca2x0y2	FLOAT	polynomial coefficients for the astrometric fit		not available
calibModNum	SMALLINT	calibration modification number
dataRelease	TINYINT	Data release

StackToImage

PSPS field	PSPS type	PSPS Description	IPP source	Comments
stackMetaID	BIGINT	stack identifier
imageID	BIGINT	hashed exposure-ccdID identifier

StackLowSigDelta/StackHighSigDelta

PSPS field	PSPS type	PSPS Description	IPP source	Comments
partitionKey	BIGINT	partition key
stackDiffID	BIGINT	ODM detection identifier
ippDetectID	BIGINT	detection id generated by IPP
filterID	TINYINT	filter ID: g=1, r=2, i=3, z=4, y=5, w=6,..
psfLikelihood	FLOAT	PSF likelihood
infoFlag	INT	indicator of strange propeties
nFrames	INT	number of frames contributing to source
htmID	BIGINT	HTM index for the detection
zoneID	INT	Zone index
raErr	FLOAT	estimated error in ra
decErr	FLOAT	estimated error in dec
cx	FLOAT	cartesian x
cy	FLOAT	cartesian y
cz	FLOAT	cartesian z
calMag	FLOAT	calibrated magnitude
calMagErr	FLOAT	estimated error in calMag
dataRelease	TINYINT	Data release when this detection was taken

Unresolved fields for stack stage

Not yet...