Wide-Field-of-View Longwave Camera for the Characterization of the Earth’s Outgoing Longwave Radiation

Abstract

The measurement of the Earth’s Outgoing Longwave Radiation plays a key role in climate change monitoring. This measurement requires a compact wide-field-of-view camera, covering the 8–14 µm wavelength range, which is not commercially available. Therefore, we present a novel thermal wide-field-of-view camera optimized for space applications, featuring a field of view of 140° to image the Earth from limb to limb, while enabling a high spatial resolution of 4.455 km at nadir. Our cost-effective design comprises three germanium lenses, of which only one has a single aspherical surface. It delivers a very good image quality, as shown by the nearly-diffraction-limited performance. Radiative transfer simulations indicate excellent performance of our camera design, enabling an estimate of the broadband Outgoing Longwave Radiation with a random relative error of 4.8%.

Mosaicing Technology for Airborne Wide Field-of-View Infrared Image

“…et al proposed a remote sensing image matching method based on Non-Subsampled Contourlet Transform (NSCT) and Speed Up Robust Features (SURF) [14]. Schifano, L. et al proposed a new method for accurately stitching airborne images acquired from multiple sensor imagers [15]. Gao, R. et al proposed an adaptive multi-view and real-time image mosaic method based on the combination of grayscale and feature [16].…”

A Multispectral Camera Suite for the Observation of Earth’s Outgoing Radiative Energy

“…A reference design of the thermal imager is described in [25]. The thermal imager consists of a microbolometer detector array with a WFOV lens allowing us to view the Earth from limb to limb.…”

“…A reference design of the visible imager is described in [24]. A reference design of the thermal imager is described in [25]. A new space mission concept, called the Earth Climate Observatory (ECO), for the accurate and stable monitoring of the EEI is currently elaborated upon, building further on the basic concepts in [6,24,25].…”

“…In this paper, we describe an advanced multispectral camera suite with performance that goes beyond [24,25]'s reference designs in terms of spectral information content. In Section 2, we describe the advanced shortwave camera suite.…”

Optical Design of a Novel Wide-Field-of-View Space-Based Spectrometer for Climate Monitoring

“…Our previous research efforts have already addressed innovative spaceborne instrumentation with the aim of improving climate change monitoring by means of a better assessment of the Earth’s radiation budget. These instruments include (1) a radiometer to measure the total incoming solar radiation and total outgoing terrestrial radiation [ 14 ], (2) a first camera to measure shortwave radiation [ 15 ], and (3) a second camera to measure longwave radiation [ 16 ]. These three instruments are part of our space mission project named the Earth Climate Observatory (ECO) (previously known as ASTERIX [ 17 ]).…”