Parent Topic: <A href="http://www.pcigeomatics.com/cgi-bin/pcihlp/MIAVHRR|PARAMETERS">PARAMETERS</a><hr>
<H4>DBGC</H4>
Specifies the database GCP segment to receive the ground control
points. Elevation values are set to 0. Only Level 1b LAC/HRPT and
GAC formats provide GCP data. For these formats, up to 255 GCPs are
taken from the input window (up to 17 GCPs per line and up to 15
lines from the input window). Each GCP in the DBGC segment actually
consists of a X/Y coordinate pair and a corresponding lat/long
coordinate pair. The X/Y coordinate values are similar to pixel/line
coordinates except that X/Y coordinate values begin at 0.0 (as
opposed to 1) and do not have to be integral. This allows the
specification of points within a pixel as a GCP (for increased
accuracy). As an example, consider a 200 pixel by 100 line image.
The center of the top-left pixel in this image would have X/Y
coordinates of (0.5, 0.5). The center of the bottom-right pixel
would have X/Y coordinates of (199.5, 99.5). The exact center of the
image would have X/Y coordinates of (100.0, 50.0). The single GCP
reported in the AVHRRSEG text segment also follows this format.
<P>
<PRE>
 EASI&gt;DBGC=i
 EASI&gt;DBGC=                   | new segment will be created
</PRE>
If MTIW is different in size from DBOW, no GCP segment is written.
<P>
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Parent Topic: <A href="http://www.pcigeomatics.com/cgi-bin/pcihlp/MIAVHRR|PARAMETERS">PARAMETERS</a><br>
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