Computer Science
Scientific paper
Jun 2002
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2002esasp.474e..24j&link_type=abstract
Proceedings of the SPECTRA Workshop - The concept of a space-borne Earth Observation Mission addressing the terrestrial componen
Computer Science
Scientific paper
A mixture of soil and vegetation is an important category of land surfaces over which significant angular variations in thermal infrared radiance (TIR) are observed. The architecture of vegetation canopies leads to significant variability of radiative and convective energy fluxes in the canopy space. The latter implies significant thermal heterogeneity and, with that, changes of the observed surface temperature with view angle. Studies based on model simulations and field measurements show large angular variations of the brightness surface temperatures, which may be usable to infer vegetation and soil temperatures. Under these considerations mentioned above, an operational algorithm is proposed to retrieve soil and foliage component temperatures over heterogeneous land surface. Firstly, a simple linear model of thermal infrared radiation of foliage-soil mixture is developed which allows to use directional measurements made at very different zenith view angles. The second Along-Track Scanning Radiometer (ATSR-2) onboard the European Remote Sensing satellite (ERS) is presently the only one available to provide quasi-simultaneous bi-angular multi-spectral data from visible to thermal infrared bands at two view angles. In addition to three thermal infrared channels centered at 3.7 μm, 11 μm and 12 μm and one short wave infrared channel at 1.6 μm, ATSR-2 has three additional visible-near infrared channels centered at 0.56 μm, 0.67 μm and 0.87 μm intended for vegetation analysis. Such data represent an opportunity to explore the potential information on both spectral and directional observations, in view of the preparation of a new generation of multi-angle and multispectral satellite sensors. In this study, a split-window method is developed to eliminate the atmospheric effects on the two thermal infrared channels. An advanced method using all four visible, near-infrared and short wave channel measurements at two view angles is developed to perform atmospheric corrections in those channels allowing simultaneous retrieval of aerosol opacity and land surface bi-directional reflectance.Then, four visible, near-infrared and short wave infrared channels are used to estimate the fractional vegetation cover within a pixel. Finally, soil and foliage temperatures in a pixel are derived using the developed ratiative transfer model. Several case studies are carried out with ATSR-2 data. The results indicate that both foliage and soil temperatures can be retrieved from bi-angular surface temperatures measurements. Improvement of land surface process models is feasible through the use of the separate retrievals of different component (soil and foliage) temperatures in a pixel. Limitations and uncertainties in retrieving component temperatures using the present algorithm are discussed. Angular measurements at higher spatial resolution are necessary to obtain a more accurate validation of the proposed methods.
Jia L.-L.
Li Zhao-Liang
Menenti Massimo
Su Zhongbo
No associations
LandOfFree
An operational algorithm for inferring soil and foliage component temperatures from ATSR-2 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with An operational algorithm for inferring soil and foliage component temperatures from ATSR-2, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and An operational algorithm for inferring soil and foliage component temperatures from ATSR-2 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1893818