The next piece of the puzzle that I needed to solve was how to et the GPS waypoints into OCAD easily. The scenario is that I mark a waypoint of a boundary marker or a boulder or that old abandoned corn combine while I am out field checking. Then, when I get back in front of the computer I magically transfer that point into OCAD.
OCAD is not a full featured GIS application, at least not version 8. It only acepts DXF files, which are an ancient output format of autocad. Wikipedia has a nice page explaining the format and a link to the official definition. OCAD doesn't need a full fledged file, ust the points section. Here's an example with just two points:
0
SECTION
2
ENTITIES
0
POINT
8
cbwaypoints
10
688166
20
3701504
30
0
0
POINT
8
cbwaypoints
10
688222
20
3701658
30
0
0
ENDSEC
0
EOF
I was able to take the gpsx file from the GPS, and using GPSBabel and a perl program I wrote for my Mac, massage it into the correct format. As long as I name the waypoints in a certain format, I can grep them and convert to a dxf fle.
OCAD imports these in a gray color, marked with a plus sign, with no symbol defined. It's necessary to select them and convert them to the appropriate symbol.
Now it remains to be seen how accurate they are. This is the first time I have attempted to use GPS for making an orienteering map. I guess I will report back in May on the success or failure of this experiment.
my son used a gps to map a trail by having it record his route while he walked the trail. Then he used GPSUtility to convert the route into something that OCAD could read. It took a little doing but after we figured it out, the trail popped up on his OCAD map. We just used the trial version of GPS UTILITY which was free. (try searching GPS UTILITY to get info.
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