Tag Archives: github

More Map Scripts

In the last installmentโ€ลฝ I wrote a script (gdal_slice.py) to cut up geotagged images and save them in a format that GPSdrive will read. I’ve uploaded that script into a new repository on GitHub.

I’ve also uploaded a script I wrote called get_quad.py, which will download USGS topographic maps automatically. This script naturally complements gdal_slice.py; using the two together allows for almost-totally automatic population of GPSdrive’s map database with high quality topographic maps.

usage: get_quad.py [-h] [-q] [-s STATE] (-g | -c COORD COORD)
Get DRG USGS quad for given latitude and longitude from LibreMaps.org
optional arguments:
 -h, --help show this help message and exit
 -q, --silent don't produce any output
 -s STATE, --state STATE
 Postal abbr. for the state in which the quad falls, so
 we don't need to look it up
 -g, --gps get coordinates from GPSd
 specify latitude N and longitude E (respectively) in
 decimal degrees; longitude should be negative, as all
 maps fall in the western hemisphere

Unfortunately, because of the way USGS maps are organized, the script needs to know the state in which the coordinates fall. If the -s flag is not given, this is inferred from the coordinates, but this lookup requires internet access.