Index: /trunk/doc/release.2015/ps1.detrend/detrend.tex
===================================================================
--- /trunk/doc/release.2015/ps1.detrend/detrend.tex	(revision 40707)
+++ /trunk/doc/release.2015/ps1.detrend/detrend.tex	(revision 40708)
@@ -1582,5 +1582,5 @@
 along the rows of the cells that are not stable.  This common feature
 across the columns of cells results in a ``saw tooth'' pattern
-horizontally across an the mosaicked OTA, and as the background model
+horizontally across the mosaicked OTA, and as the background model
 fits a smooth sky level, this induces over- and under subtraction at
 the cell boundaries.