A Study On Geometric Calibration Of Digital Photogrammetric Airborne Sensor Using A Test Field

The geometric calibration of the airborne photogrammetric sensor is the key part in photogrammetry. The purpose of the geometric calibration is to validate and verify the accuracy of the sensor. Focusing on the theme of geometric calibration, the theories, processing and methods for the digital airborne sensor were mainly discussed in this dissertation using a test field. Based on several schemes designed for the geometric calibration of the ADS40 and DMC sensor, a lot of experiments were carried out. Some useful conclusions were gained from the experimental results. The main works and innovations are listed as follows:1. Based on the basic theory of geometric calibration of digital airborne sensor using a test field, the workflow and mathematical model of the calibration, as well as the model of GPS/IMU supported photogrammetry were all analyzed. The self calibration was proposed to offset the system errors of the sensors, and the guideline of the geometric calibration was also analyzed in this dissertation.2. Focusing on the mathematical model of geometric calibration for the ADS40 and DMC sensors, the self calibrated bundle adjustment was proposed for the geometric calibration of these two sensors. The effects of factors, such as flight strip arrangement, amount of GCP, and additional parameters of the self calibrated model and so on, influencing the accuracy of the sensors were analyzed through a large amount of experiments. Consequently, experimental results showed that the self calibrated model could highly improve the accuracy of these two sensors.3. A method of correcting the interior parameters and the coordinates of the CCD cell in the plate was proposed to improve the accuracy of ADS40 sensor based on a little amount of GCP. Experimental results showed that the accuracy of the ADS40 sensor could highly improved without GCP and self calibrated model when using the new parameters generated from the method proposed above.4. Moreover, another new method of correcting the interior parameters and the coordinates of the CCD cell was proposed for the ADS40 sensor based on the images from two different height levels. This method was proved feasible to highly improve the accuracy of ADS40 without GCP and self calibrated model through a lot of experiments.5. A method of correcting the interior parameters of the DMC sensor was proposed based on a little amount of GCP using self calibrated bundle adjustment. It was indicated that the DMC sensor was in a good condition by the fact that the new parameters generated from this method was proved to be consistent with the original interior parameters through experiments. Meanwhile, the method was also proved feasible for the geometric calibration of the DMC sensor.