Is https://registry.opendata.aws/terrain-tiles/ not a supported format? about geotiffcog

[johnjore]

Looking good, does not crash when the coordinates are within the boundaries of the TIF file and it spits out a number that looks accurate. Thanks for the quick turn around!

[fabric-io-rodrigues]

Hi @johnjore, thanks for posting your issue.

I added a small correction to support the integer raster type (INT) there was a code that applied the value 0 (if there was no factor), so it would always be returned zero.

Also, to obtain the height value using this raster (which is projected in meters) it will be necessary to inform the lat/lon (y,x) in meters.

In your example:

double lat = -37.4075974;
double lon = 145.7524722;
// change to:
double lat = -4496073.92;
double lon = 16225090.99;

Can see more in: https://epsg.io/transform#s_srs=4326&t_srs=3857&x=145.7524722&y=-37.4075975

And you can also use the URL directly in the function (without having to download it from S3), see the example below:

string url_s3 = "https://elevation-tiles-prod.s3.amazonaws.com/geotiff/10/926/626.tif";
GeoTiff geoTiff = new GeoTiff(new Uri(url_s3), directoryTemp);
double value = geoTiff.GetElevationAtLatLon(lat, lon);

Please confirm if this information is useful and solve the problem, so that we can close it.