Index: trunk/doc/release.2015/ps1.analysis/Makefile =================================================================== --- trunk/doc/release.2015/ps1.analysis/Makefile (revision 39822) +++ trunk/doc/release.2015/ps1.analysis/Makefile (revision 39823) @@ -3,7 +3,9 @@ help: @echo "USAGE: make (target)" - @echo " targets: all analysis" + @echo " targets: all analysis stages" all: analysis.pdf stages.pdf +stages: stages.pdf +analysis: analysis.pdf ANALYSIS = analysis.tex Index: trunk/doc/release.2015/ps1.analysis/stages.tex =================================================================== --- trunk/doc/release.2015/ps1.analysis/stages.tex (revision 39822) +++ trunk/doc/release.2015/ps1.analysis/stages.tex (revision 39823) @@ -1,4 +1,5 @@ -\documentclass[iop,floatfix]{emulateapj} +% \documentclass[iop,floatfix]{emulateapj} % \documentclass[iop,floatfix,onecolumn]{emulateapj} +\documentclass[12pt,preprint]{aastex} % \pdfoutput=1 @@ -106,29 +107,29 @@ The processing database is colloquially referred to as the `gpc1' database, since a single instance of the database is used to track the -processing of images and data products related to the PS1 GPC1 -camera. This same database engine also has instances for other -cameras which the IPP has processed, e.g., GPC2, the test cameras TC1, -TC3, the Imaging Sky Probe (ISP), etc. +processing of images and data products related to the PS1 GPC1 camera. +This same database engine also has instances for other cameras +processed by the IPP, e.g., GPC2, the test cameras TC1, TC3, the +Imaging Sky Probe (ISP), etc. Within the processing database, the various processing stages are represented as a set of tables. In general, there is a top level table which defines the conceptual list of processing items either to -be done, in progress, or completed. An associated table will list the -specific details of elements which have been processed. For example, -one critical stage is the Chip processing stage, discussed below, in -which the individual chips from an exposure are detrended and sources -are detected. Within the gpc1 database, there is a top-level table -called `chipRun' in which each exposure has a single entry. -Associated with this table is the `chipProcessedImfile' table, which -contains one row for each of the (up to 60) chips associated with the -exposure. The top-level tables, such as chipRun, are populated once -the system has decided that a specific item (e.g., an exposure) should -be processed at that stage. Initially, the entry is given a state of -`run', denoting that the exposure is ready to be processed. The -low-level table entries, such as the chipProcessedImfile entries, are -only populated once the element (e.g., the chip) has been processed by -the analysis system. Once all elements for a given stage, e.g., chips -in this case, are completed, then the status of the top-level table -entry (chipRun) will be switched from 'run' to 'done'. +be done, in progress, or completed. An associated table lists the +details of elements which have been processed. For example, one +critical stage is the Chip processing stage, discussed below, in which +the individual chips from an exposure are detrended and sources are +detected. Within the gpc1 database, there is a top-level table called +`chipRun' in which each exposure has a single entry. Associated with +this table is the `chipProcessedImfile' table, which contains one row +for each of the (up to 60) chips associated with the exposure. The +top-level tables, such as chipRun, are populated once the system has +decided that a specific item (e.g., an exposure) should be processed +at that stage. Initially, the entry is given a state of `run', +denoting that the exposure is ready to be processed. The low-level +table entries, such as the chipProcessedImfile entries, are only +populated once the element (e.g., the chip) has been processed by the +analysis system. Once all elements for a given stage, e.g., chips in +this case, are completed, then the status of the top-level table entry +(chipRun) are switched from `run' to `done'. If the analysis of an element (e.g., chip) completed successfully, @@ -137,5 +138,5 @@ recorded. An analysis which results in a fault is one in which the failure is thought to be temporary. For example, if a computer had a -network glitch and was unable to write out some of the result files, +network glitch and was unable to write out some of the output files, this would be an ephemeral failure which was not a failing of the data, but merely the processing system. On the other hand, if the @@ -514,11 +515,42 @@ and objects}. +\section{Difference Images} + +Two of the primary science drivers for the Pan-STARRS system are the +search hazardous asteroids and the search for Type Ia supernovae to +measure the history of the expansion of the universe. Both of these +projects require the discovery of faint, transient source in the +images. For the hazardous asteroids, and solar system studies in +general, the sources are transient because they are moving between +observations; supernovae are stationary but transient in brightness. +In both cases, the discovery of these sources can be enhanced by +subtracting a static reference image from the image taken at a certain +epoch. The quality of such a difference image can be enhanced by +convolving one or both of the images so that the PSFs in the two +images are matched. \note{discuss Alard-Lupton}. + +In the Difference Image stage, the IPP generates diffferece images for +specified pairs of images. It is possible for the difference image to +be generated from a pair of warp images, from a warp and a stack of +some variety, or from a pair of stacks. During the PS1 survey, pairs +of exposures, call TTI pairs (see~\note{Survey Strategy}), were +obtained for each pointing within a $\approx$ 1 hour period in the +same filter, and to the extent possible with the same orientation and +boresite position. The standard PS1 nightly processing generated +difference images from the resulting warp pairs (`warp-warp diffs'). + +The nightly stacks generated for the Medium Deep fields were combined +with a template reference stack image to generate `stack-stack diffs' +for these fields each night. + +For the PV3 processing, the entire collection of warps for the $3\pi$ +survey were combined with the $3\pi$ stacks to generate `warp-stack +diffs'. + \begin{verbatim} -Outline: DVO Ingest Calibration IPP to PSPS PSPS Load & Merge -Difference \end{verbatim}