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edwardoughton / itmlogic

Longley-Rice Irregular Terrain Model (itmlogic)
https://itmlogic.readthedocs.io/en/latest/?badge=latest
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How to use ETOPO5 with terrain_module? #65

Closed WorksWellWithOthers closed 2 years ago

WorksWellWithOthers commented 2 years ago

Hello, I passed the alwdgg.tif file from ETOPO5 to

measured_terrain_pforilfe, distance_km, points = terrain_p2p(
    os.path.join(dem_folder, 'alwdgg.tif'), line)

When the distance is great (8000km) the path loss comes out to be 800+.

Comparing the alwdgg.tif with the original_surface_profile_m the values of alwdgg.tif seem way off (+3000 to -4900) in the range where original_surface_profile_m is above 0 (15 to 201).

Is there a recommended .tif file to use with the terrain_module? Should I be converting the etopot5/alwdgg.tif in some way to be compatible?

WorksWellWithOthers commented 2 years ago

I don't HAVE to use the etopo5 tif file. It was the easiest to grab after needing a new .tif file since the ASTGTM2_N51W001_dem.tif wasn't covering the coordinates I was passing.

WorksWellWithOthers commented 2 years ago

Tried converting to ft to m. I'll have to look for another dem tif file. Don't remember much about this one that I grabbed. Are the values in the original_surface_profile_m meters or km? I'm guessing the _m stands for meters.

WorksWellWithOthers commented 2 years ago

surface_profile_m : list Contains surface profile measurements in meters.

WorksWellWithOthers commented 2 years ago

ETOPO5 Info

Downloaded: https://www.eea.europa.eu/data-and-maps/data/world-digital-elevation-model-etopo5 Info: https://www.ngdc.noaa.gov/mgg/global/etopo5.HTML

The download source doesn't match the info but I think it would be fair to say the data is in meters.