Context
The goal of the FOSTER²NAV project was to develop and test a flash lidar sensor capable of supporting the GNC systems of exploration missions. A flash lidar is able to measure 3D images in a much wider range of distances than classic stereo cameras. Applications for such a sensor are e.g. the evaluation of the landing area or during rendezvous and docking maneuvers.
FOSTER²NAV began in 2010 and ended successfully in mid 2014. The partners in this EU-funded FP7 project were CSEM, VTT, Modulight and Airbus. The project’s homepage can be found here.
The DLR Institute of Space Systems was responsible for the dynamic testing on short-range indoor tests and long-range outdoor tests. The goal of the tests was to verify the functionality and performance of the flash lidar.
Test Concept and Activities
The flash lidar was tested at three test sites: TRON, an airfield and EPOS. The high level approach was:
The main activities during the preparation of the tests included:
Indoor Tests in TRON
TRON was the first of the three test sites. The laboratory environment was best suited for the beginning of the test campaign, for commissioning the sensor and getting hands-on feeling. Furthermore, in TRON the focus was set on acquiring high precision (about 1 mm) ground truth data. By analyzing sensor data and ground truth data the sensor parameters of bias and noise could be determined.
The flash lidar was tested under the following parameters:
Outdoor Tests at Airfield
Complementary to our indoor activities the sensor was also tested outdoors. The goal was to test the flash lidar under higher speed and longer range relative to the target compared to what could be realized in TRON. Due to the high laser optical power involved the tests were conducted on the military airfield in Fassberg, Germany.
The sensor target was a 3 m x 3 m plane, equipped with primitive bodies. For mobility, the sensor was installed on the test-car including a battery-based power supply. As in TRON, also for the outdoor tests ground truth data was recorded. For doing so, a navigation system was developed with a mobile part installed on the car and a stationary part located near the target.
The navigation system comprised:
In Fassberg, the sensor was tested under the following parameters: