The compact High Speed Scanning Lidar (HSSL) was designed to meet the requirements for a rover GN&C sensor. The
eye-safe HSSL's fast scanning speed, low volume and low power, make it the ideal choice for a variety of real-time and
non-real-time applications including:
Vehicle guidance and Navigation;
Spacecraft Landing / Hazard Avoidance.
The HSSL comprises two main hardware units: Sensor Head and Control Unit. In a rover application, the Sensor Head
mounts on the top of the rover while the Control Unit can be mounted on the rover deck or within its avionics bay. An
Operator Computer is used to command the lidar and immediately display the acquired scan data.
The innovative lidar design concept was a result of an extensive trade study conducted during the initial phase of an
exploration rover program. The lidar utilizes an innovative scanner coupled with a compact fiber laser and high-speed
timing electronics. Compared to existing compact lidar systems, distinguishing features of the HSSL include its high
accuracy, high resolution, high refresh rate and large field of view. Other benefits of this design include the capability to
quickly configure scan settings to fit various operational modes.
In August 2007, the engineering model of the Rendezvous Lidar System (RLS) was tested at the Sensor Test Range
Facility that has been developed at NASA Langley Research Center for the calibration and characterization of 3-D
imaging sensors. The three-dimensional test pattern used in this characterization is suitable for an empirical verification
of the resolving capability of a lidar for both mid-range terminal rendezvous and hazard avoidance landing. The results
of the RLS lidar measurements are reported and compared with image frames generated by a lidar simulator with an
Effective Instantaneous Field of View (EIFOV) consistent with the actual scanning time-of-flight lidar specifications.
These full-scale tests demonstrated the resolving capability of the lidar under static testing conditions. In landing
operations, even though the lidar has a very short exposure time on a per-pulse basis, the dynamic motion of a lander
spacecraft with respect to the landing site will cause pulse-to-pulse imaging distortion. MDA, Optech, and NGC
Aerospace have teamed together to resolve this issue using motion compensation (platform stabilization) and motion
correction (platform residual correction) techniques. Platform stabilization permits images with homogenous density to
be generated so that no safe landing sites will be missed; platform residual errors that are not prevented by this
stabilization are then corrected in the measurement data prior to map generation. The results of recent developments in
platform stabilization and motion correction are reported and discussed in the context of total imaging error budget.
The Spaceborne Scanning Lidar System (SSLS) system is a space-qualified scanning lidar system developed by MDA and Optech. It has been operating on orbit since April 2005 as part of the XSS-11 one-year demonstration of space technologies associated with spacecraft autonomous rendezvous and proximity operations. The SSLS has already successfully supported long and medium-range object acquisition and tracking. Short range acquisition, tracking, and imaging tasks are scheduled towards the end of its one-year mission. MDA and Optech view SSLS as the first 'smart' product in the RELAVIS line of scanning lidar products. An upgrade plan, addressing customer needs and lessons learned during SSLS build and operation on orbit, has been established and is currently being implemented. Next generation SSLS lidar will provide improved performance and real-time space object tracking solution based on point cloud data acquired by the lidar. Real-time pose (position and orientation) capability will be provided in addition to the currently provided range, bearing, and centroid telemetry data. The integrated pose solution will provide the user with tracking data while reducing spacecraft databus and processor utilization. This new functionality expands the SSLS role from a 'sensor only' ranging role to a robust long/medium and short range 'ranging and tracking solution' supporting rendezvous and close proximity missions. This paper describes the SSLS upgrade plan and provides information related to the implementation and progress of the upgrade via test results of the new SSLS capabilities.
The Spaceborne Scanning Lidar System (SSLS) system is a space qualified scanning lidar system developed by MDA, Space Missions (MD Robotics) and Optech. It is scheduled to be launched in 2005 as part of a one year on-orbit demonstration of space technologies associated with spacecraft autonomous rendezvous and proximity operations. The SSLS was designed to meet specific performance requirements under all lighting conditions during its one-year mission. Prior to delivery to the customer, the SSLS completed a successful proto-flight testing program that demonstrated SSLS capability to perform its intended mission in its target space environment. The SSLS is a product of a successful fusion of proven terrestrial lidar technologies with space proven hardware and software designs. The SSLS product was developed, qualified and delivered to a customer within an extremely demanding schedule. This paper describes the requirements, design constraints and architecture of the SSLS. The paper includes scan results which demonstrate its performance and capabilities at short and long ranges.