Terrain elevation and associated functionalities added with TERRAIN plugin v1.0

[yaofuzhou]

Dear BlueSky Community,

I have implemented the initial version of the plugin TERRAIN.

To test TERRAIN on your end,

1. configure the terrain_and_skyline section in settings.cfg. You may want to request an Open Topography key for free, and use it to replace the default key. The default bounding box is placed around Vienna that everyone loves.

2. Run plugin terrain in the BlueSky console. Stand by for the plugin to download necessary dataset and to initialize its functions.

3. Create an aircraft within the set bounding box. E.g., a 747 over Vienna,
   cre A b744 48.2, 16.3 0m 10000 200

4. pan A.

5. Run AGL A for the updated above-ground level of A. You may hear a sound that says the AGL value in feet 🙄🙄🙄

6. Mute that sound in settings.cfg with agl_mute = True 🤣🤣🤣

7. Run groundmsl A or groundmsl 48.2, 16.3 to check the ground elevation below A or at (lat, lon) = (48.2, 16.3).

8. Run SHOWELEMAP to print a drawing of the terrain elevation map in .pdf and .png formats.

Please kind let me know if you have spotted any issue for me to fix, especially if I have broken any convention of BlueSky that I am not aware of.

As always, suggestions for me to improve and expand the plugin TERRAIN are much welcomed.

Cheers,

Yaofu

P.s. we can totally make landing aircraft say "50, 40, 30, 20, 10, retard, retard, retard..." if you want this (useless?) feature!

[jooste]

Thanks for this interesting plugin! I have a couple of suggestions:

• All variables added to settings should be provided with a default using settings.set_variable_defaults(), because right now successful loading of the plugin depends on having certain contents in your settings.cfg file
• Additional (temporary/downloaded) datafiles should be placed in the cache dir, not the navigation data dir
• Some critical info is only printed to the terminal. It would be useful to see these messages in the bluesky echo window as well.
• If you move initialisation of terrain data to a stack function, your plugin can load 'instantly'. Also, this avoids the echo commands you currently have in the root of your plugin file.