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There have been suggestions recently that Google Earth is a “powerful tool” for science. Some disagree. At least one amateur used Google Earth to find an asteroid impact crater.

I just wanted to give context to imagery viewed in ENVI (similar to my Google Maps user function). mg_write_kml produces a KML file and an image suitable for viewing in Google Earth. The KML file includes lat/lon information to locate the image. The user function is only one file: mg_write_kml (docs).

Let me know if you use Google Earth for science and if this user function is useful for you.

Continue reading “Google Earth user function for ENVI.”

I upgraded to Version 2 of the Google Maps API. The benefits of Version 2 of the API that are applicable for the ENVI lookup user routine are:

1. The Overview map control displays a collapsible overview map in the lower-right corner of the browser window.
2. The Javascript is half the size, so it should be a faster download.
3. Increased imagery resolution and coverage.
4. Other customization features make future enhancements to mg_google_lookup possible.

The best part is that all the changes are on the server side, so this will just happen automatically for those who are using mg_google_lookup already. If you for some reason want to keep using Version 1 of the Google Maps API, change the URL inside mg_google_lookup from “envi_lookup.html” to “envi_lookup1.html”.

See previous post Google Maps lookup for ENVI.

This ENVI user function will add a “Find location using Google Maps” in the Tools menu of the display window for any image with map information. Selecting it will bring up the location of the image with Google Maps in your default browser.

Also included is a helper routine called mg_open_url which is useful in general to open an URL in the default browser from IDL. It will work on any IDL platform. On UNIX platforms, the first time it is used it requires the user to locate the web browser. It stores this location and uses it for future calls. This is not necessary on Windows and Mac since they have a nice way to start the default application for URLs.

ENVI and an internet connection are required to use this ENVI user function.

Installation instructions

1. Download mg_google_lookup.sav or the source code.
2. Move the .sav file or .pro files into the save_add directory of your ENVI distribution.
3. On UNIX (but not Mac or Windows) platforms, the first time mg_google_lookup is used it will ask for the location of the web browser you want to use to display the Google Maps.