What's New for Postage Stamp Server Version 2

Bill Sweeney 2013-05-03

This page describes new features available in the IPP Postage Stamp server with version 2 of the request specification released 2013-05-02. A pdf of the specification is attached to PostageStampServer.

The ipp programs pstamp_request_file and psmkreq have been updated to create files in this format. The server happily accepts files in version 1 as well.

Request File Header

Two new keywords are defined for the header

ACTION string "PROCESS"

EMAIL string email of user submitting the request

ACTION is a new keyword that tells the system what to do with the request file. Users building and submitting their own request files should always set ACTION to the value PROCESS.

The web interface will use other values for this keyword to trigger the server's "preview" mode.

EMAIL is used to track the user that submitted the request file. Users are encouraged to provide a valid value. (We promise no spam ;)

Request Table Columns

The most important new feature of Version 2 is the integration with the IPP's new release tracking system ipp_release_tracking. The IPP now has tables which clearly identify collections of runs with certain versions of the pipeline.

Two columns in the request specification are used to select images of interest using the release system.

SURVEY_NAME is a string used to select which survey from which to select images. Allowed values are the same as the PSPS survey definitions.

+-------------+--------------------------------------------------------------+
| SURVEY_NAME | description                                                  |
+-------------+--------------------------------------------------------------+
| 3PI         | PS1 3PI Survey                                               | 
| MD01        | PS1 MD01 XMM-LSS-DXS 022224-043000                           | 
| MD02        | PS1 MD02 CDFS/GOODS/GEMS 033224-274800                       | 
| MD03        | PS1 MD03 IFA/Lynx 084300+444000                              | 
| MD04        | PS1 MD04 COSMOS 100000+021200                                | 
| MD05        | PS1 MD05 Lockman-DXS 110000+570000                           | 
| MD06        | PS1 MD06 NGC 4258 121857+471814                              | 
| MD07        | PS1 MD07 VISTA-Video1 140000+050000                          | 
| MD08        | PS1 MD08 EliasN1-DXS 160000+570000                           | 
| MD09        | PS1 MD09 Vimos4-DXS-SSA 220000+003000                        | 
| MD10        | PS1 MD10 Deep2 233000+000000                                 | 
| M31         | PS1 M31 Andromeda 004242+411600                              | 
| STS1        | PS1 STS1 Outskirts of Bulge 195048+170339                    | 
| CAL01       | PS1 Cal North Pole 000000+900000                             | 
| CAL02       | PS1 Cal SA92 Dense Landolt Std Field 005808+004232           | 
| CAL03       | PS1 Cal Perseus Cluster / Abell 426 031900+413300            | 
| CAL04       | PS1 Cal SA95 Dense Landolt Std Field 065207+001710           | 
| CAL05       | PS1 Cal Taurus dark cloud (diverse extinction) 043000+250000 | 
| CAL06       | PS1 Cal SA98 Densle Landolt Std Field 065207+001710          | 
| CAL07       | PS1 Cal M81-M82-HolmIX (Local Group) 095640+692200           | 
| CAL08       | PS1 Cal Virgo Cluster (Center) 123000+130000                 | 
| CAL09       | PS1 Cal Hercules Cluster (Center) 160508+1745+28             | 
| CAL10       | PS1 Cal M17-M24 Region 181400+000544                         | 
| CAL11       | PS1 Cal SA110 Dense Landolt Std Field 184207+000544          | 
| CAL12       | PS1 Cal Kepler Mission Astrometric field 192240+443000       | 
| CAL13       | PS1 Cal 3C454.1 (Northern field) 225033+712919               | 
| STS2        | PS1 STS2 Hyades 004000+150000                                | 
| STS3        | PS1 STS3 Praesepe 083000+200000                              | 
| SSS         | PS1 Solar System Survey                                      | 
+-------------+--------------------------------------------------------------+

Note that at this time the release tables are only populated for 3PI, SSS, and the MD surveys. We do not expect that the CAL surveys will ever be populated.

IPP_RELEASE is used to specify a particular target release. If the user knows the precise reduction for a particular exposure or stack skycell this parameter is used. Note that if a particular release is not specified, the system will choose the "best" by preferring data from higher "priority" releases.

For example the most recent "grand reprocessing" of the 3PI survey is identified with the IPP_RELEASE 3PI.PV3. If a user requests stamps from a particular position on the sky, images will be selected from the highest priority (generally the latest) reduction. 3PI.PV3 for exposures that were included in that release. If an exposure was missing for whatever reason from 3PI.PV3 images will be selected from the 3PI.PV2, 3PI.PV1, or 3PI.nightly releases in that order.

Note that byid requests bypass the release system since by definition these requests specify the exact images to be chosen.

Also the release tables do not currently handle diff images so SURVEY_NAME and IPP_RELEASE are currently ignored.

DATA_GROUP is ignored when SURVEY_NAME or IPP_RELEASE is supplied (except for diff images).

RUN_TYPE is a new column used to narrow searches for stack and diff images. For stacks this value is only used if the release system is used to select stacks. When supplied it restricts stacks to particular types. Valid values are: deep, reference, nightly, and notnightly. (notnightly means any stack_type except "nightly")

RUN_TYPE may be used to filter lookups for diff images. The valid values are warp_warp, warp_stack, and stack_stack.

The last of the new columns are FWHM_MIN and FWHM_MAX. These may be used to restrict selected images to a range of measured seeing. At the current time these parameters are not used unless SURVEY_NAME or IPP_RELEASE is supplied and are not used at all for diff images. For stacks this is only available for released stacks that have been calibrated by running staticsky and skycal stages. Unfortunately this means that they are not useful for nightly stacks.

The units of the fwhm values are pixels: ~.258 arcseconds per pixel for single frame images and .25 or .258 depending on the tessellation for stacks and diffs.

The values are compared to the fwhm_major columns in the ipp database. For raw, chip, and warp images these values are compared to camProcessedExp.fwhm_major. For stacks it is the fwhm_major value in the skycalResult table.

Sources from postage stamps

When sources are requested the system now returns a cmf file containing only the sources from the region of interest. Previously it returned a copy of the entire input cmf.

For chip stage the sources are extracted from the corresponding camera stage smf file. For historical magic related reasons requests for chip stage cmfs were previously silently ignored.

Warp stage sources are extracted from the warp stage cmfs.

For stacks sources from the staticsky/skycal stages are returned if the stack is marked as calibrated in the release tables. If the release tables are not used to find the stack, the latest staticsky cmf for the stack is returned.

Previously it returned the cmf from the stack stage which were sources detected in the input exposures and thus were not particularly useful.

If neither of the above sources for sources is found the server silently returns no cmf.

Zero Points

For stacks selected using the release system which are marked as being calibrated, data from the header from the skycal cmf file is included in the image postage stamps.

This means that the zero points measured by the skycal stage are given. More info to be supplied.

For chip and warp stage images the headers will be augmented from results of the DVO calibration analysis including information about the "ubercalibration" of the exposure. For more information see wiki:calib_info_in_pstamp Calibration information in postage stamps]