Relating remote sensor signals to ground-truth information

This paper describes two computer-based methods for data handling and display which significantly simplify the task of relating remote sensor signals to that ground-truth information which can be derived from aerial photographs of the ground scene. These techniques have been applied successfully to microwave radiometer and infrared spectrometer flight-test data. Results indicate that the digital computer, with its associated storage and display capabilities, makes possible systematic and accurate analysis of remote sensor data in large volume at low cost. In one approach, the computer is used to determine and display, on aerial photographs, the exact path of the sensor boresight over the ground scene. Using this display, an investigator can observe visually certain simple correlations between the sensor return and the ground scene. In the second approach, the analyst uses a special light-pen console to put ground-truth information (in graphical form) into the computer. Using techniques described here for storing, retrieving, and processing graphical data, the computer automatically converts the ground-truth information into a form where it can be correlated directly with the remote sensor signals.