Satellite Observations in Science Education

Area Estimator


This simple RCO is used when an instructor would like a user to estimate the area of a feature within an image, based solely on an embedded units scale and a visual estimate. The instructor can specify via XML the number of guesses to allow before revealing the correct answer, and the percent error to allow. You can't expect the user to make an exact guess!

The instructor must provide an image in a standard web format (such as .gif or .jpg) which has the target feature clearly highlighted and provides a scale appropriate for the units of measurement.

The sample XML file provided below must be populated with appropriate data (the correct answer, ancillary information about the image, etc.) and placed in the same location as the HTML file used to access and present this RCO.

Example usage:

This link will bring up a separate browser window with a page that uses this RCO.

Snapshot of sample use:

Example use of Area Estimator RCO

How to use

  1. Create an HTML file which will reference and load this RCO. Cut-and-paste the sample applet tag below and insert at the location in the HTML file you want to use the RCO.
  2. Create an XML file with input data based on the example below.
  3. Create an image file with a scale and the target feature clearly outlined.
  4. Download the RCO by right-clicking the download link below and choosing "Save Link Target As..."
  5. Edit the applet tag parameters to reference your new file names, and test.

Create your XML file one of two ways:

  Edit this sample Area Estimator XML file

  Generate your XML automatically with this link.

This RCO bundled as a jar file

home pageHome Comments? Contact us    This project is sponsored by NASA  NASA logo