ERDAS IMAGINE 2016, allows technicians and analysts to measure of features straight from satellite imagery. The user is presented with 3 options:
- Base Shadow Height – Derive the height of a feature based on the length of the shadow cast along the ground.
- Height from Layover – Derive the height of a feature based on relief displacement (layover) effects in the image
- Top Shadow Height – Derive the height of a feature based on the shadow cast from the top of the feature to the ground
Now, by measuring the shadow and using the sun elevation and azimuth recorded at the time of image capture, you can calculate the height of objects in your imagery!
In the example right, the tower rises from the center of the memorial, so we need to use the Top Shadow Height option to measure the building. We place a point at the top of the spire, then a second point at the tip of the shadow. The software does the rest! And, just like before, you can save the measurements directly into vector attributes.