This script queries elevation data for a rectangle in order to overlay with a google map and visualizes it as an image or contour map. Extraction of the elevation data is based on the Google Elevation API. Please find the description and rules of the Google Elevation API here.Created by Christoph Hofstetter (christophhofstetter (at) gmail.com) August 2013 V0.21
Enter latitude and longitude of the North West and South East corner of the area you want to sample. Select how many samples you want in each direction, the script works best for squares. If you go beyond 2500 total samples per day, querying data may stop working according to the API description. Click get data and the text area below should populate with numbers, the actual elevation in meters. (If you already have the data you can also copy it there to make plots.)
You can visualize the data as a contour map. Click the button create contour map and you will see the plot. You can save the figure as an svg file by copying the text below and creating an new .svg file from it. Then, use for example Inkscape to overlay with google maps. Example data is filled from the beginning, click create contour map to get an impression, or replace directly with your coordinates and retrieve the data.
This script was developed with the Firefox browser and may not work in other browsers. No warranty whatsoever is given, including but not limited to functioning or correctness.