Material Evaluation Framework of Additive Manufactured Aluminum Alloys for Space Optical Instruments

A framework for additive manufacturing aluminum alloy selection was developed to determine the preferred composition and process parameters from which to fabricate topology-optimized optical instrument housings and light-weighted freeform mirrors for the Compact Hyperspectral Air Pollution Sensor (CHAPS). In recent years, a number of high...

Calibration of a spectral imager with a widely tunable radiance source

A spectral imager is calibrated for radiance with an uncertainty < 1 % using an SI-traceable narrow-band tunable radiance source, which is based on an optical parametric oscillator and an integrating sphere.

Calibration of a CubeSat spectroradiometer with a narrow-band widely tunable radiance source

We have developed an SI-traceable narrow-band tunable radiance source based on an optical parametric oscillator (OPO) and an integrating sphere for the calibration of spectroradiometers. The source is calibrated with a reference detector over the ultraviolet/visible spectral range with an uncertainty of < 1%. As a case study, a CubeSat spectro...

CHAPS: a sustainable approach to targeted air pollution observation from small satellites

Adverse air quality impacts human health and climate and has implications for environmental equity. The Compact Hyperspectral Air Pollution Sensor (CHAPS) is a newly designed small imaging spectrometer for remote sensing of nitrogen dioxide (NO2) and other air pollutants from space. It incorporates two emerging technologies, to achieve the...

Absolute Radiometric Reference Instrument (ARRI)

The cheapest method for an instrument to perform radiometric monitoring in orbit is to compare its radiometric response from a scene to the known radiance of that same scene. This is known as vicarious calibration. The known radiance of this scene comes mostly from other space instruments. The limiting factors of this vicarious calibration...

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...

Design of a new thermal vacuum chamber for space instrument calibration

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...

Radiometric calibration of the gome-2 instrument

The Global Ozone Monitoring Experiment-2(GOME-2) represents one of the European instruments carried on board the MetOp satellite within the ESA’s “Living Planet Program”. Consisting of three flight models (FM’s) it is intended to provide long-term monitoring of atmospheric ozone and other trace gases over a time frame of 15–20 years, thus...

From ozone monitoring instrument (OMI) to tropospheric monitoring instrument (TROPOMI)

Technology evolution of the Tropomi instrument

TROPOMI is the sun backscatter trace gas instrument on ESA's Sentinel-5 precursor satellite. TROPOMI builds upon a rich heritage from similar instruments, the main ones being SCIAMACHY on ESA's ENVISAT and OMI on NASA's AURA satellite. This paper explains how the technology from the heritage instruments evolved, considering high level design...

Enhancement of diffusers BRDF accuracy

Enhancement of diffusers BSDF accuracy: spectral features effect

This paper reports the activities performed in the framework of the ESA contract 18432/04/NL/AR: Enhancement of diffusers BSDF Accuracy. This study was conducted to investigate properties of various diffusers. Diffusers are widely used in space instruments as part of the on-board absolute calibration. Knowledge of the behavior of the diffuser is...