[FWTools] Help with Georeferencing and Reprojecting FAA Charts

James Trimble jimmit.t at gmail.com
Wed Oct 8 13:09:22 EDT 2008

Hi, I am trying to georeference and reproject an FAA Enroute IFR chart.  You
can find the pdf version of this chart at
http://www.jamestrimble.info/US<goog_1223485636161>L32 31 JUL

The parameters are
L-32  1:14NM (1020787)
GP 47 56 09.6N 063 04 30.3W (Upper Right)
GP 46 02 46.4N 079 29 47.0W (Upper Left)
GP 41 48 34.9N 078 00 33.5W (Lower Left)
GP 43 35 36.2N 062 37 08.3W (Lower Right)

Top Standard Parallel 45 00 00N
Bottom Standard Parallel 33 00 00N
Central Meridian 95 00 00W
Origin 39 00 00N 95 00 00W

Datum = North American Datum of 1983

Ultimately, I'd like to have this map in a mercator projection to overlay
with google maps.

The commands I tried to use are :

gdal_translate -a_srs "+proj=lcc +lat_1=45.0 +lat_2=33.0 +lat_0=39.0
+lon_0=95.0 +datum=NAD83" -a_ullr -79.4964 46.0462 -62.6190 43.5934 -of
GTiff -co "INTERLEAVE=PIXEL" "C:\Documents and Settings\James\Desktop\US L32
31 JUL 08_CROPPED.png" .\USL32.tiff

gdalwarp -of GTiff -co "INTERLEAVE=PIXEL" -s_srs "+proj=lcc +lat_1=45.0
+lat_2=33.0 +lat_0=39.0 +lon_0=95.0 +datum=NAD83" -t_srs "+proj=merc
+datum=NAD83" .\USL32.tiff .\USL32_MERC.tiff

I would really appreciate some help on how to do this correctly.

Thank you very much,
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