Radio mobile can produce radio transmission coverage charts based on a set of particulars related to a transmitter and a receiver. Such a thing is good to theoretically predict signal coverage in various terrain. Since the program can use SRTM data for terrain backgrounds it is reasonably useful when visualized on a GIS. The files produced when creating a coverage plot can be in various formats, .png, .tif, .kml etc but no geo-referencing data is embedded in the file so it cannot be dropped into
QGIS or
Tilemill for instance over a geo-referenced map background. External files containing the georeferencing data are produced but in my case I needed the data embedded in a single file.
I use the following
GDAL commands to translate, warp and embed metadata in the image file so that it can be dropped into QGIS or Tilemill. I used a .png as an output from Radio Mobile which has a native alpha transparency channel so that the white parts of the picture become transparent. You can play with the various color schemes to get a good visual result. For Tilemill I used WGS84.
The radio Mobile setup was:
Picture Properties
Radio Plot Properties
Using the results of a plot named Picture16.png which is 1680 pixels by 1024 and Picture16.geo that was created while saving the picture file, use the the following command sets geographic positions for each corner pixel starting at top left (-gcp 0 0) moving clockwise, and writes to a file called temp.tif:
# gdal_translate -of GTiff -a_ullr 17.07981 49.19989 21.52019 47.40011 -a_srs EPSG:4326 -expand rgba Picture16.png output.tif
I hope someone finds this useful as I messed around for some time getting it to work, I'm sure there are other ways to get it done and don't hesitate to point out any better ways.
