def get_elevation(self, lat, lon):
"""
Returns the elevation in metres of point (lat, lon).
Uses bilinar interpolation to interpolate the SRTM data to the
required point.
"""
print "lon, lat: ", lon, lat
print "geotransform : ", gdal.InvGeoTransform(self.geotransform)
col_f, row_f = gdal.ApplyGeoTransform(gdal.InvGeoTransform(self.geotransform), lon, lat)
col = int(col_f)
row = int(row_f)
# NOTE - THIS IS A FIDDLE TO STOP ERRORS AT THE EDGE OF
# TILES - IT IS NO CORRECT - WE SHOULD GET TWO POINTS
# FROM THE NEXT TILE.
#if row==5999: row=5998
#if col==5999: col=5998
if row>3600: row=3600
if row>3600: row=3600
if col>3600: col=3600
if col>3600: col=3600
htarr = gdalnumeric.DatasetReadAsArray(self.tile['dataset'], col, row, 2, 2)
height = bilinear_interpolation(htarr[0][0], htarr[0][1], htarr[1][0], htarr[1][1],
row_f-row, col_f-col)
return height
def get_elevation(self, lat, lon):
"""
Returns the elevation in metres of point (lat, lon).
Uses bilinar interpolation to interpolate the SRTM data to the
required point.
"""
row, col, row_f, col_f = self.pos_from_lat_lon(lat, lon)
# NOTE - THIS IS A FIDDLE TO STOP ERRORS AT THE EDGE OF
# TILES - IT IS NO CORRECT - WE SHOULD GET TWO POINTS
# FROM THE NEXT TILE.
#if row==5999: row=5998
#if col==5999: col=5998
if row==1200: row=1199
if row==1199: row=1198
if col==1200: col=1199
if col==1199: col=1198
#~ print row, col
htarr = gdalnumeric.DatasetReadAsArray(self.tile['dataset'], col, row, 2, 2)
height = bilinear_interpolation(htarr[0][0], htarr[0][1], htarr[1][0], htarr[1][1],
row_f-row, col_f-col)
return height