In order to accurately complete an aerial LIDAR survey it is important that the sensor is properly calibrated. Airborne LIDAR calibration can be a complex and daunting task. TerraScan and TerraMatch are a wonderful toolset to assist the analyst in determining and correcting these systematic errors. While the program can be operated much like a black box solution, it’s always helpful to understand what one is observing in order to get the best answer. I like to use the analogy that TerraMatch is like a calculator – the answer it gives depends upon the input you give it. Or the more colloquial expression, “garbage in, garbage out”. Hence, I always try to stress the importance of understanding one’s dataset in order to calibrate the best data for the end user.
The calibration consists of a few components. The first is the most important and that is the calibration efforts performed by the system manufacturer to ensure that the hardware is functioning within specification and with the expected reliability. The second component is generally a boresight flown and computed by the acquisition vendor to validate the system functionality and repeatability. Thirdly, there is the project calibration that is done by the acquisition vendor in order to verify system functionality on any given project, while tightening the dataset to remove inherent systematic errors.