I have a digital terrain model and a digital surface model which contain data in an Esri grid. The data in this files looks like this
ncols 1251 nrows 1001 xllcorner 742499.5 yllcorner 328999.5 cellsize 1.0 nodata_value 9999.00 -9999 -9999 5 2 -9999 20 100 36 3 8 35 10 32 42 50 6 88 75 27 9 13 5 1 -9999
See also: https://en.wikipedia.org/wiki/Esri_grid
What I would like to do now is to calculate the height of positions through substractions of the values from the DTM and DSM.
I imagine this quite easy, as long as I can convert the
xllcorner value to coordinates like 15,34° N.
What I want to do finally is put in coordinates a user selects on map and return the height of objects at this point. I want to solve this with PHP, so I need a formular to convert the
I'm new to this, so maybe I image this much easier than it is, but I'm thankful for hints.