Next-gen sensor for multi- and hyperspectral imaging from space

The new hyperspectral sensor contains a line-based filter on chip, featuring a broad spectral range (450-900 nm) and high, uniform light sensitivity. It is suited to meet stringent signal-to-noise ratio (SNR) requirements for earth observation from small satellites. Moreover, the optimised process technology ensures a very low sensor-to-sensor variability making these sensors ideal for satellite constellations. The new sensor enables high-quality images for a range of multi- and hyperspectral imaging applications from space, including monitoring of food systems, agriculture, biodiversity, water and air quality, and mining.

The use of spectral imaging from space is experiencing rapid growth, with many companies building constellations of small satellites to, for example, screen for plant diseases, monitor coastal areas or calculate biomass indices for forest management. Such satellites rely heavily on advanced sensors to gather accurate and detailed data. A critical requirement for these sensors is a broad spectral range and high sensitivity. A wider spectral range allows for the detection of a variety of features, while good light sensitivity ensures that even faint signals can be accurately captured.

To realise the new sensor, imec monolithically integrated specialised thin-film spectral filters on a CMV2000 sensor (AMS) with a track record in space applications. The resulting sensor provides an across-flight resolution of 2048px with a 2/3” optical format and operates at frame rates up to 340fps in full resolution. Multiple regions of interest (ROI) can be defined on the sensor, providing the flexibility to serve different types of missions: the sensor can be operated at full spectral resolution or specific bands can be selected, reducing data load while increasing frame rate and SNR.

With 96 bands, the sensor’s spectral range covers 450-900 nanometres, equidistantly divided into accurately positioned spectral bands, with a more uniform filter transmission efficiency throughout the complete spectral range compared to the first generation. Achieving 10 digital TDI (time-delayed-integration) stages per band, the sensor doubles the TDI capability of the detector compared to the previous generation, consequently offering maximum SNR across its entire wavelength range and allowing for more accurate detection of features, important for environmental monitoring from space. Moreover, imec has optimised the fabrication process, resulting in low sensor-to-sensor variability, ensuring accurate analysis and reduced processing time.

By integrating thin-film filters monolithically onto the AMS sensor, imec has created a robust and stable configuration.  Unlike alternative setups that place separate optical elements between the lens and sensor, the integrated design guarantees an exceptional filter to detector alignment and is resistant to shocks, vibrations, and temperature fluctuations—a significant advantage for the harsh conditions of space.

The sensor is available off-the-shelf for individual purchase units, providing low-barrier access to advanced technology and enabling businesses to start with a single unit for evaluation or to enter into supply agreements for larger quantities.