Query to Pull Out Elevations

[KralE911]

I am using Google Earth Pro and I have a list of Lat Longs that I need to find elevations for, I can do this by hand but am wondering if there is a way to pull it out as the list is rather large. Any help would be appreciated

Thanks!
John

[barryhunter]

Not out of Google Earth there isn't. However see this page:

http://www.nearby.org.uk/elevation-kml.php

This has two things, 1) a list of webservices that you can query to get elevation yourself, and 2) the ability to upload a KML and it will use said webservices to find the elevation of the points it finds in the KML, and give you back a new file with the elevations filled out!

Hope that helps,

[mcshea98]

KralE911,

Google Earth altitude data is not an exact science. I wanted to let you know a couple things about pulling altitude data from Google Earth.

Before I start, I want to note that I do not work for Google and I do not have any inside information. The following are my own (and other GEC members) deductions.

1. Google Earth uses WGS-84 data for it's lat-long (see documentation). Other datums must be converted first before pulling altitude data.
2. Google Earth altitudes are a mixture of different levels of detail. (Not confirmed)
3. It appears that GE does not use anything higher than DTED Level 1 (equivalent to USGS DEM 1).
___Note: DTED data comes in three main levels.
___ Level 0: 1 data point per 1000 m
___ Level 1: 1 data point per 100 m
___ Level 2: 1 data point per 30 m (This data is usally classified)
4. DTED data is not even 100% accurate. Below is the accuracy for DTED Level 1.
___ Absolute Horizontal +/- 50 meters at 90% CE (Circular Error)
___ Absolute Vertical +/- 30 meters at 90% LE (Linear Error)

Conclusion: Google Earth altitude data is not "Survey Quality" and should be used with that in mind. However, pulling the altitude data from Google Earth can help you create some better KML and KMZ files.

Hope this helps.

p.s. If anyone has better information on any of these conclusions, please post them.

[asxless]

Seer has posted in the data forum that the Global Elevation Data used in GE is the "90m SRTM" data set.

http://bbs.keyhole.com/ubb/showthreaded.php/Cat/0/Number/397443/page//vc/1

What hasn't been verified is how much massaging GE staff did to that data set and what data set(s) GE uses in the very high/low lattitudes outside the 90m SRTM data set coverage.

FWIW If I was lookng for elevation data at specific locations, I'd use a data source that has better known provence, where I could pull the actual data points and interpolate the elevation(s) myself.

-- asxless in iLand

[jpwade]

good input/info KralE911,

check out the elevations here, http://bbs.keyhole.com/ubb/download.php?Number=402878

note the bridge ridge created in the DEM,
elev north of ridge: 2691
elev top of ridge: 2787
elev south of ridge: 2700

[Valery35]

See also primary files data

http://glcf.umiacs.umd.edu/data/srtm/
ftp://ftp.glcf.umiacs.umd.edu/glcf/SRTM/
http://glcfapp.umiacs.umd.edu:8080/esdi/

If need use this images as overlay.