The DOQQs on MAGIC are in the JPEG compressed format. You can either expand them
using the djpeg.exe utility or use them as JPEGs in MapInfo or ArcVIEW. In fact,
if your machine has enough RAM, you can open them with the Netscape Browser.
There is a quick way to geo-reference the JPEG for MapInfo 4.0 and ArcView 3.0.
Both programs use the GEO-TIF protocol. The program will look for an ASCII file
which shares the file name but has a "w" as the last character in the name.
Therefore, FILENAME.JPG and FILENAME.JPW will work.
We have processed part of the header file for each quarter quadrangle. The
coordinates of the upper left corner and quad corner tics are included in the
record in both UTM NAD27 and NAD83:
This report is for the SE Quarter of the BASHBISH FALLS Quad DOQQ
The aerial photo was taken on: 31-March-1991
Number of rows = 5940 Number of columns = 7680
UTM NAD27 Upper Left Corner (1, 1) 628917.628, 4658085.576
NAD27 Quad Corner Tics (Dashed Crosses)
629281.069, 4657683.048 634452.454, 4657779.443
629407.808, 4650743.531 634584.265, 4650839.903
UTM NAD83 Upper Left Corner (1, 1) 628950.000, 4658310.000
NAD83 Quad Corner Tics (Solid Crosses)
629277.501, 4657896.658 634448.743, 4657993.050
629404.241, 4650957.045 634580.556, 4651053.415
The format of the ASCII file is:
1
0
0
-1
628917.628
4658085.576
Where:
1
0
0
-1
are indicating the meter designation and
628917.628
4658085.576
are the UTM NAD27 Upper Left Corner (1, 1) 628917.628, 4658085.576
You can create your own file by clipping the "upper left corner" coordinates and
pasting them into a file. Beware that these are UTM and not State Plane
Coordinates, so CT DEP and other data from the MAGIC collection will not align
without some extra work. The issues of coordinate systems and projections are
fraught with complications. Go to "Map Projection Texts and Software" and follow
the links to software in order to resolve the UTM => Connecticut State Plane
Coordinate issue.
