Progress in freeform mirror design for space applications

Off-axis systems with freeform mirrors is a design approach of increasing importance for space instruments. While the off-axis reflective approach allows simple, versatile and obstruction free designs, the use of freeform surfaces allows to achieve better optical performance and/or compactness. In recent years, many such instruments have been...

Sentinel 5 instrument and UV1 spectrometer subsystem optical design and development

Sentinel-5 is an Earth atmospheric monitoring mission developed within the European Union’s Copernicus program. The mission objective is to monitor the composition of the Earth’s atmosphere on a daily basis. Airbus DS GmbH acts as the prime contractor under a European Space Agency contract. The instrument design, development, and the instrument...

In-orbit characterization of the ISRF

Recent Earth Observation instruments require a highly accurate knowledge of their Instrument Spectral Response Function (ISRF). This translates into lengthy and costly characterisation programs during the Assembly, Integration, and Test phase of the instrument. In addition, potential changes of ISRF after launch suggests to use an on-board...

Development of an efficient, highly uniform Sun Simulator for optical space instrument calibration

In space Earth Observation related projects, Sun Simulators are regular used for on-ground calibrations of the flight instruments. Instrument radiometric calibration is established by illuminating the on-board diffuser(s) via the Sun port in irradiance configuration and an external OGSE calibrated diffuser for the radiance configuration via the...

Optical satellite communication space terminal technology at TNO

Optical communications will complement radio frequency (RF) communications in the coming decades to enhance throughput, power efficiency and link security of satellite communication links. To enable optical communications technology for intersatellite links and (bi-directional) ground to satellite links, TNO develops a suite of technologies in...

Performance validation of a high-bandwidth fine steering mirror for optical communications

This paper presents the first test results of a novel Fine Steering Mirror (FSM) for optical communication terminals. The FSM utilizes efficient variable reluctance actuators, tailored for the specific application, making it highly compact and power efficient. The test results demonstrate a high dynamical performance of <1.7kHz closed-loop...

Traceable radiance source for spectroradiometer calibration

SI traceable calibration of satellite instruments like spectroradiometers get increasingly important in space-based observation for various reasons. First, requirements on measurements in terms of accuracy, dynamic range and wavelength range get increasingly demanding. Second, long term observations require SI traceability for comparability of...

SPEXone: A compact multi-angle polarimeter

We have developed a 6 dm3-sized optical instrument to characterize the microphysical properties of fine particulate matter or aerosol in the Earth atmosphere from low Earth orbit. Our instrument can provide detailed and worldwide knowledge of aerosol amount, type and properties. This is important for climate and ecosystem science and human...

Freeform optics design tool for compact spectrometers

We present a novel optical design tool that makes use of an evolutionary global optimization algorithm. The algorithm has several characteristics that make it well-suited for freeform optics design. With the design tool it is no longer necessary to make the distinction between paraxial degrees of freedom and degrees of freedom related to...

Characterisation and performance verification results of the earthcare multi spectral imager VNS camera

The European Space Agency (ESA) and the Japan Aerospace Exploration Agency (JAXA) are co-operating to develop the EarthCARE satellite mission with the fundamental objective of improving the understanding of the processes involving clouds, aerosols and radiation in the Earth's atmosphere. A Cloud Profiling Radar (CPR), an Atmospheric LIDAR (ATLID...

Electromagnetic deformable mirror for space applications

To increase the collecting power and to improve the angular imaging resolution, space telescopes are evolving towards larger primary mirrors. The aerial density of the telescope mirrors needs to be kept low, however, to be compatible with the launch requirements. A light-weight (primary) mirror will introduce additional optical aberrations to...

First aircraft test results of a compact, low cost hyperspectral imager for earth observation from space

In recent years TNO has investigated and developed different innovative opto-mechanical designs to realize advanced spectrometers for space applications in a more compact and cost-effective manner. This offers multiple advantages: a compact instrument can be flown on a much smaller platform or as add-on on a larger platform; a low-cost...

Lisa telescope assembly optical stability characterization for ESA

The LISA Optical Stability Characterization project is part of the LISA CTP activities to achieve the required TRL level for all of the LISA technologies used. In 2012 the LISA mission was reformulated and transferred to the New Gravitational Observatory (NGO), which has similar performance requirements. This activity targets the demonstration...

Optical coatings for the Tropomi UV channel

Earth observation measurements at wavelengths below 320nm are challenging due to the steep decrease of the earth irradiance towards shorter wavelengths. Stray light and ghosting of longer wave light can easily overwhelm the signals at short wavelengths. In the UV channel (270-320nm) of the TROPOMI instrument this challenge has been addressed...

Design and characterization of the blazed holographic UV gratings for Tropomi

Optical components such as diffraction gratings are widely used in Space-flight satellites to analyse light properties from soft-X rays to Infra-Red. The diffraction gratings are one of the key optical components of space-flight instruments and have to exhibit very high optical performances. TROPOMI (Tropospheric Monitoring Instrument) is a...

The Tropomi instrument: Last steps towards final integration and testing

The Tropospheric Monitoring Instrument TROPOMI is ready for system level verification. All sub-units have been integrated and tested and final integration at Dutch Space in Leiden has been completed. The instrument will be subjected to a testing and calibration program and is expected to be ready for delivery to the spacecraft early 2015. Using...

A platform for European CMOS image sensors for space applications

Both ESA and the EC have identified the need for a supply chain of CMOS imagers for space applications which uses solely European sources. An essential requirement on this supply chain is the platformization of the process modules, in particular when it comes to very specific processing steps, such as those required for the manufacturing of...

Cryogenic optical performance verification methods for optical components, coatings and optical systems

NOVA-ASTRON has delivered a suite of cryogenic astronomical instruments for large ground based telescopes as well as space missions. The instruments include polarimeters, spectrometers, cameras and interferometers, mostly operating at infrared. Several methods have been developed to verify or measure, under cryogenic conditions, the performance...