Hi Candarco,

you are very lucky to work in USA where there are plenty of free altimetric data (i.e.DEM, DSM, LiDAR). Why are you using Google Earth elevation data (30m GSD data (AMSL) from NASA's Shuttle Radar Topography Mission) for your tests ?

Here some useful links to find alternative data sources:

USGS - What types of elevation datasets are available, what formats do they come in, and where can I download them?
https://www.usgs.gov/faqs/what-t ... here-can-i-download

5 Free Global DEM Data Sources – Digital Elevation Models
https://gisgeography.com/free-global-dem-data-sources/

Anyway, if you need a very detailed Digital Surface Model (DSM) i agree that the best procedure is that described by "aebrilievi".

Maurizio

Hi Candarco,

you are very lucky to work in USA where there are plenty of free altimetric data (i.e.DEM, DSM, LiDAR). Why are you using Google Earth elevation data (30m GSD data (AMSL) from NASA's Shuttle Radar Topography Mission) for your tests ?

Here some useful links to find alternative data sources:

USGS - What types of elevation datasets are available, what formats do they come in, and where can I download them?
https://www.usgs.gov/faqs/what-t ... here-can-i-download

5 Free Global DEM Data Sources – Digital Elevation Models
https://gisgeography.com/free-global-dem-data-sources/

Anyway, if you need a very detailed Digital Surface Model (DSM) i agree that the best procedure is that described by "aebrilievi".

Maurizio