Changeset 39823

Timestamp:

Nov 24, 2016, 11:21:10 AM (10 years ago)

Author:

eugene

Message:

updates to stages.tex

Location:

trunk/doc/release.2015/ps1.analysis

Files:

• Makefile (modified) (1 diff)
• stages.tex (modified) (4 diffs)

trunk/doc/release.2015/ps1.analysis/Makefile

@@ -3 +3 @@
 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 

trunk/doc/release.2015/ps1.analysis/stages.tex

@@ -1 @@
-\documentclass[iop,floatfix]{emulateapj}
+% \documentclass[iop,floatfix]{emulateapj}
 % \documentclass[iop,floatfix,onecolumn]{emulateapj}
+\documentclass[12pt,preprint]{aastex}
 % \pdfoutput=1
 
@@ -106 +107 @@
 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 +138 @@
 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 +515 @@
   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}