This paper describes a high-resolution optical filter (HRF) suitable for narrow bandwidth filtering in LIDAR applications. The filter is composed of a broadband interference filter and a narrowband Fabry-Perot etalon based on the capacitance stabilised concept. <p> </p>The key requirements for the HRF were a bandwidth of less than 40 pm, a tuneable range of over 6 nm and a transmission greater than 50%. These requirements combined with the need for very high out-of-band rejection (greater than 50 dB in the range 300 nm to 1200 nm) drive the design of the filter towards a combination of high transmission broadband filter and high performance tuneable, narrowband filter.
The European Space Agency (ESA) foresees several robotic missions aimed for the preparation of the future Human Exploration of Mars. To accomplish the mission objectives Imaging LIDARs are one of the identified technologies that shall provide essential information to the spacecraft Guidance, Navigation and Control (GN&C) system. ESA awarded two technology development contracts to two industrial teams for the development and demonstration of novel technologies for Imaging LIDAR sensors. Both teams designed and are manufacturing an Imaging LIDAR breadboard targeting one specific application. The objective of using novel technologies is to reduce substantially the mass and power consumption of Imaging LIDAR sensors. The Imaging LIDAR sensors shall have a mass <10kg, power consumption <60Watt, measure distances up to 5000m, with a field of view (FOV) of 20x20 degrees, range resolutions down to 2 cm, and a frame rate higher than 1 Hz.
3D LIDAR imaging is a key enabling technology for automatic navigation of future spacecraft, including landing,
rendezvous and docking and rover navigation. Landing is typically the most demanding task because of the range of
operation, speed of movement, field of view (FOV) and the spatial resolution required. When these parameters are
combined with limited mass and power budget, required for interplanetary operations, the technological challenge
becomes significant and innovative solutions must be found. Single Photon Avalanche Photodiodes (SPADs) can reduce
the laser power by orders of magnitude, array detector format can speed up the data acquisition while some limited
scanning may extend the FOV without pressure on the mechanics. In the same time, SPADs have long dead times that
complicate their use for rangefinding. Optimization and balance between the instrument subsystems are required. We
discuss how the implementation of real-time control as an integral part of the LIDAR allows the use of SPAD array
detectors in conditions of high dynamics. The result is a projected performance of more than 1 million 3D pixels/s at a
distance of several kilometers within a small mass/power package. The work is related to ESA technology development
for future planetary landing missions.