How to look up elevation data by lat/lng [closed]

Answer 1

I bought a GEOIP database and store every single post long lat data in mysql. After that i just implement the Google Map API by passing dynamic longlat data to the Google MAP. What I get is all my post shown in the Google Map and also display nearest post from a certain location

What you need is a GEOIP database, A query that calculate distance in miles base on given longlat, Google API, PHP Dynamic passing API variables.

example of my site : Matchimedia.com.

Answer 2

I recently stumbled in to this question while doing research. I don't have a complete simple answer either, but there are some other options not listed in the answers so far:

• Google Elevation API: 25,000 requests/day, limited to Google Maps applications
• Lat/Lon to Elevation: 2 points / second
• GPSVisualizer: no published speed, but not intended for general DEM use
• Shuttle Radar Topography: alternative to the NED, 7 gigabytes for the US.

Answer 3

I'll give you one of the best "secrets" that I learned throughout the years after going through many different pains (leeching scripts, manual clicking, etc). It is an old-school trick... contact a real person there!

The best way do get the NED elevation dataset is to contact USGS's Eros group directly at bulkdatainfo_at_usgs.gov

You send them an external drive and after 4 to 8 weeks (usually much less than that) they will send you the entire dataset that you requested.

Then use GDAL to query your points in a way similar to this example. You may want to read the Affine Geotransform section of the GDAL Data Model

Answer 4

The USGS Elevation Query Web Service only allows one query at a time, but it allows you to make requests with SOAP, HTTP GET, or HTTP POST. Choose your favorite language and write a script to generate requests for each of your data points.