Solutions

Mission

Imaging spectroscopy greatly extends the scope of traditional remote sensing. It is based on the detection of many narrow, contiguous spectral bands. This presents opportunities for more precise identification of surface materials than is possible with broadband multispectral sensors.

APEX has been designed to serve the needs of a broad palette of Scientific Users in the fields of simulation, calibration and validation of variables; atmospheric chemistry and physics; vegetation and ecology; geology, soils and minerals; coastal and inland waters; snow and ice; urban areas; algorithm development.

In addition, APEX was intended as a simulator and a calibration / validation device for future spaceborne hyperspectral imagers. Although the intended spaceborne sensors (PRISM, LSPIM, SPECTRA, ..) were cancelled during the APEX development, the hyperspectral imager was used to simulate and complement important Earth Observation missions such as Sentinel, PROBA-V, MEDUSA, FLEX, ..
APEX will easily team up with future spaceborne missions.

OIP’s Participation

OIP, as subcontractor to RUAG [CH], was responsible for the design, development and testing of the imaging spectrometer.

Status:

The first flight in a Dornier Do-228 Aircraft of DLR (Deutsches Luft- und Raumfahrt) took off from Oberpfaffenhofen airfield (Munich, Germany) on October 13th, 2008 and acquired 13 flight lines over Wittenverge (Germany).

APEX was intensively tested with multiple test flights over Switzerland, Germany and Belgium and with pre- and after flight CHB (Calibration Home Base) campaigns in October 2008 and in June 2009. The Swiss and Belgian target areas were selected in order to cover a variety of possible scientific applications. Flight lines have been executed over forests, crops, inland water, urban and coastal areas to derive a wide spectrum of products of interest. Vicarious calibration campaign with extensive ground truth measurements has been carried out for all flight lines.

APEX became the first airborne imaging spectrometer of ESA available to the user community from 2011 onwards. Fully operational since 2011 and still providing exquisite data.

Partners

The APEX instrument is developed by a Swiss-Belgian consortium on behalf of ESA. OIP was subcontractor to RUAG [CH].

The most important users are RSL (Remote Sensing Laboratories) [CH] and VITO (Flemish Institute for Technological Research) [B].

The project was funded by ESA/PRODEX.