Google Earth Elevations vs SRTM

[RonMan]

Hi,

Scenario is:

I downloaded SRTM from USGS.

Another company has downloaded elevations from Google Earth.

Now there is a difference in elevations between the two terrains.

Is it really possilble to download Google Earth Elevation data?

Does Google earth use SRTM?

I have seen videos that downloads from Google Earth but from what i experienced before is that the downloaded elevations are not the same with the Google Earth Software.

Please direct me to proper community if i have posted in the wrong forum since i am unsure where to post this.

Thank you.

Ron

[DanPatterson_Retired]

SRTM is at a much coarser spatial resolution than most elevation products.

Do you need it for an area not covered at a finer resolution?

[RonMan]

Hi Dan,

yes.  I always go for usgs srtm for our linear projects (hundreds of kilometers) for highways and rails.  

Hi Robert,

Thanks for the link unfortunately our current projects are located outside US particularly African countries and Kosovo.

Thanks,

Ron

[IanMurray]

Personally I am very leery of the terrain information within Google Earth.  There seems to be some issues with tree affecting the elevations in some areas within Google Earth, as well as some asymptotic like features where there should be none when drawing elevation profiles of a line. 

[RobertBorchert]

By nature of the fact that they push it across the internet you can rest assured that the overall accuracy is very low. If you tried to push high accuracy elevation data across the web it would be very slow.

[IanMurray]

True but its not even necessarily an accuracy problem, but an outright error problem in some cases.  I've never found anywhere that adequately explains the source of the terrain data in Google Earth, there has been alot of conjecture about its a combination of SRTM with other data in some places, but the fact I often find artifacts from trees would tend to lead me away from that.  There are areas that you can find much higher quality terrain information in Google Earth where they have incorporated LiDAR or other high resolution data, but if you are outside of those areas, how useful the data is becomes highly questionable to me.

[RobertBorchert]

If your location is CONUS I would point towards

https://datagateway.nrcs.usda.gov/

to download the LIDAR data (if available for that area) and create your own contours at a high accuracy.

Fortunately where I live we have LIDAR coverage available for the state from the State and we can download specific tiles.

[IanMurray]

I would consider looking at the Terrain Elevation Layer from ESRI Living Atlas, they regularly incorporate higher resolution data into their Terrain Layer for use.  Obviously you are working in some remote/not well sampled areas, but there should be at least some 24m meter data(as opposed to the 30m SRTM) from the AirBus data they incorporated lately.

Coverage Area overview for their various data sources can be viewed here

[RobertBorchert]

http://www.diva-gis.org/gdata

[RobertBorchert]

https://www.eea.europa.eu/data-and-maps/data/eu-dem