Optics for NIORD imager of NorSat-4 satellite
Reference project
Spherical and aspherical lenses for exploring Arctic waters
Satellites play a crucial role in monitoring and researching the Earth. The NorSat missions of the Norwegian Space Agency (NOSA) are specifically designed to monitor Arctic waters. The NorSat-4 microsatellite, developed by the Space Flight Laboratory (SFL) in collaboration with the Norwegian Defence Research Establishment (FFI) and Safran Reosc, is an important step towards improving maritime safety and early detection of potential threats.
Project details
Since 2010, NOSA, FFI and SFL have been collaborating on ship-tracking missions for Norway. The NorSat-4 Maritime Tracking Satellite, like its three predecessors, is based on the DEFIANT platform (a medium-sized microsatellite platform for payloads up to 30 kg) by SFL and plays a key role in monitoring ship activities in Arctic waters. Safran Reosc developed a low-light imaging camera (NIORD imager) specifically designed for NorSat-4 to detect ships longer than 30 meters in the mostly dark Arctic waters. The integrated Automatic Identification System (AIS) allows the precise tracking of ships. The mission is part of the broad range of nano, micro, and small satellites developed by SFL for Norway.
Project realization
asphericon manufactured aspheric and spherical lenses with different sizes for Safran Reosc‘s NIORD imager. Some of them include drilling holes. The technological implementation proved to be challenging, especially for the larger aspheric lenses. The stringent requirements for surface quality with an RMSi ≤ 15nm and the avoidance of high-frequency errors increased the complexity of the manufacturing process. The challenge was to obtain optics with polishing errors whose high and medium spatial frequencies are close to zero. The optics were successfully realized thanks to the intensive support of asphericon‘s technology department and cooperation with Safran Reosc‘s optical design team, through a continuous development process involving repeated measurements and polishings (including High-End Finishing technologies, like MRF and Angström Polishing).
asphericon demonstrated its ability to provide tailored solutions with the lens manufacturing. The innovative approach made it possible to meet the demanding requirements of the NIORD project.
NorSat-4 satellite, manufactured lenses & camera system
Fig. 1 Visualization of the satellite in space © UTIAS
Fig. 2 Built-in low-light capable image camera system and
manufactured optics (top right corner) ©SAFRAN
Optics for Safran REOSC at a Glance:
- Manufacturing of aspheric and spherical lenses with different sizes
- Some optics include drilling wholes
- Surface quality: RMSi ≤ 15nm
