Index: trunk/doc/release.2015/ps1.detrend/detrend.tex
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--- trunk/doc/release.2015/ps1.detrend/detrend.tex	(revision 39852)
+++ trunk/doc/release.2015/ps1.detrend/detrend.tex	(revision 39853)
@@ -125,4 +125,52 @@
 %% http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?2007ASPC..364..153M&data_type=PDF_HIGH&whole_paper=YES&type=PRINTER&filetype=.pdf
 \section{Introduction and Survey Description}
+
+This is the third in a series of seven papers describing the Pan-STARRS1
+Surveys,
+the data reduction techiques and the resulting data products. This paper (Paper III)
+describes the details of the pixel processing algorithms, including
+detrending, warping, and adding (to create stacked images) and subtracting
+(to create difference images) and resulting image products and their
+properties.
+\citet[][Paper I]{chambers2017} provides an overview of the Pan-STARRS System, the
+design and execution of the Surveys, the resulting image and catalog data
+products, a discussion of the overall data quality and basic
+characteristics, and a brief summary of important results.
+%Magnier et al. 2017 (Paper II)
+%Pan-STARRS Data Processing Stages
+\citet[][Paper II]{magnier2017c}
+describes how the various data processing stages are organised and
+implemented
+in the Imaging Processing Pipeline (IPP), including details of the
+the processing database which is a critical element in the IPP
+infrastructure.
+%Waters et al. 2017 (Paper III)
+%Pan-STARRS Pixel Processing : Detrending, Warping, Stacking
+%\citet[][Paper III]{waters2017}
+%Magnier et al. 2017 (Paper IV)
+%Pan-STARRS Pixel Analysis : Source Detection
+\citet[][Paper IV]{magnier2017a}
+describes the details of the source detection and photometry, including
+point-spread-function and extended source fitting models, and the
+techniques for ``forced'' photometry measurements.
+%Magnier et al. 2017 (Paper V)
+%Pan-STARRS Photometric and Astrometric Calibration
+\citet[][Paper V]{magnier2017b}
+describes the final calibration process, and the resulting photometric and
+astrometric quality.
+The Pan-STARRS1 filters and photometric system has already been described
+in detail in \cite{2012ApJ...750...99T}.
+%Flewelling et al. 2017 (Paper VI)
+%Pan-STARRS 1 Database and Data Products
+\citet[][Paper VI]{flewelling2017}
+describes  the details of the resulting catalog data and its organization
+in the Pan-STARRS database.
+%
+%
+\citet[][Paper VII]{huber2017}
+%Huber et al. 2017 (Paper VII)
+describes the Medium Deep Survey in detail, including the unique issues and
+data products specific to that survey. The Medium Deep Survey is not part
+of Data Release 1. (DR1)
 
 
@@ -1354,6 +1402,7 @@
 pixels are masked.  The large fraction of this masking is due to
 regions that fall within the vignetted region.  Defining the diameter
-of the unvignetted region to be 3 degrees, and excluding pixels that
-fall beyond this point reduces the static masking fraction to 9.7\%.
+of the unvignetted region to have be 3 degrees, and excluding pixels
+that fall beyond this point reduces the static masking fraction to
+9.7\%.
 
 Unfortunately, due to the design of the OTAs and readout cells, a
@@ -1373,5 +1422,24 @@
 across the field of view.  Dynamic masking adds an additional $2-3\%$
 on average, with advisory burntool masking contributing the largest
-single component.
+single component.  Table \ref{tab:mask fraction} contains estimates of
+the mask fraction in the GPC1 detector footprint by the sources of the
+masking for the 3 degree field of view, as well as for a larger 3.25
+degree field of view that allows addition unvignetted regions in the
+corners to contribute.
+
+\begin{deluxetable}{lcc}
+  \tablecolumns{3}
+  \tablewidth{0pc}
+  \tablecaption{Mask Fraction by Mask Source}
+  \tablehead{\colhead{Mask Source}&\colhead{3 Degree FOV}&\colhead{3.25 Degree FOV}}
+  \startdata
+  No pixel        & 4.44\% & 9.47\% \\
+  Detector defect & 6.37\% & 7.91\% \\
+  CTE issue       & 2.62\% & 3.13\% \\
+  \enddata
+  \label{tab:mask fraction}
+\end{deluxetable}
+
+