I’m also working on making equidistant azimuthal maps with qgis. I’ve gotten about as far as you. One thing I discovered that was a bit unintuitive was that I had to ‘densify’ my grid to add more points, otherwise the lines in the grid would not project correctly. Have you had any luck adding a degree reticle circle around the outside border of the map? Or adding azimuth lines radiating out from the center?
Good call overlaying the compass bitmap. It’s pretty much static for this kind of map anyway so there wouldn’t be much benefit to having it in a GIS layer, except perhaps resolution independence. Maybe that’s even possible in the composer by overlaying a vector format graphic, e.g. something in postscript or svg.
I figured out how to do the range circles in qgis. First you need to create a new points layer and add a point for your QTH. It should be at coordinate 0,0. I used the NumericDigitize plugin to be able to specify the coordinates precisely. Next go to menu Vector->Geoprocessing->Buffer. Select the QTH point layer you created. I set segments to 25; the number needs to be large enough to approximate a circle at your output resolution. Buffer distance should be in meters so 5,000km = 5,000,000 meters. Specify an output shapefile named “range1” or something. Set the CRS your custom equidistant azimuthal CRS. You should now see an opaque circle. Don’t close the buffer dialog yet, go ahead and buffer the buffer layer you just created to create the next ring, and so on. Finally once you’ve created all the rings, edit their properties, set the style of fill to No Brush. This could probably be trivially scripted.
Nice, thanks Jeff! Yes, the graphics I’ve imported into Print Composer were drawn as .svg and import in that format but I’ve uploaded .png here on this page because WordPress won’t display that format. I should upload the .svg files here when I’ve got a minute.
Thanks for sharing the buffers method, that’s much more elegant than my clunky KML drawn from an external website, after all, who knows if it will be there next time?
I’m also working on making equidistant azimuthal maps with qgis. I’ve gotten about as far as you. One thing I discovered that was a bit unintuitive was that I had to ‘densify’ my grid to add more points, otherwise the lines in the grid would not project correctly. Have you had any luck adding a degree reticle circle around the outside border of the map? Or adding azimuth lines radiating out from the center?
Good call overlaying the compass bitmap. It’s pretty much static for this kind of map anyway so there wouldn’t be much benefit to having it in a GIS layer, except perhaps resolution independence. Maybe that’s even possible in the composer by overlaying a vector format graphic, e.g. something in postscript or svg.
I figured out how to do the range circles in qgis. First you need to create a new points layer and add a point for your QTH. It should be at coordinate 0,0. I used the NumericDigitize plugin to be able to specify the coordinates precisely. Next go to menu Vector->Geoprocessing->Buffer. Select the QTH point layer you created. I set segments to 25; the number needs to be large enough to approximate a circle at your output resolution. Buffer distance should be in meters so 5,000km = 5,000,000 meters. Specify an output shapefile named “range1” or something. Set the CRS your custom equidistant azimuthal CRS. You should now see an opaque circle. Don’t close the buffer dialog yet, go ahead and buffer the buffer layer you just created to create the next ring, and so on. Finally once you’ve created all the rings, edit their properties, set the style of fill to No Brush. This could probably be trivially scripted.
Nice, thanks Jeff! Yes, the graphics I’ve imported into Print Composer were drawn as .svg and import in that format but I’ve uploaded .png here on this page because WordPress won’t display that format. I should upload the .svg files here when I’ve got a minute.
Thanks for sharing the buffers method, that’s much more elegant than my clunky KML drawn from an external website, after all, who knows if it will be there next time?
Great work, 73!
Take a look at my Great Circle Mapper program:
https://www.mapability.com/ei8ic/gcm/screenshots.php
73s Tim EI8IC