Sovremennye problemy distantsionnogo zondirovaniya Zemli iz kosmosa, 2015, Vol. 12, No. 1, pp. 190-199
Comparison of methods to assess atmosphere radiation impact on ground-based radio-polarimetric measurements
1 Space Research Institute RAS, Moscow, Russia
The paper is devoted to assessment of the influence of descending atmospheric radiation on results of radio-polarimetric measurements. Comparison of two ways to assess this component at processing experimental sea surface remote sensing data is carried out. By the first method, sky radiation is calculated according to the plane-stratified atmosphere model where key parameters are thermodynamic temperature of the near-surface atmospheric layer and its integral absorption at the central frequency of the received radiation. The second method uses results of direct radiometric measurements at view angles from horizon to zenith. For the analysis, we use the data of radio-polarimetric measurements of intensity of sea surface own radiation obtained during the international field experiment CAPMOS (Combined Active/Passive Microwave Measurements of Wind Waves for Global Ocean Salinity Monitoring) in 2005. By the example of gravity-capillary wave spectra parameters retrieval (Non-Linear Radiothermal Resonance Spectroscopy method (NRRS)) it is shown that the two atmosphere radiation assessment methods lead to dramatic disparity between values of restored parameters. So, in presence of clouds and other atmospheric formations, the estimates of spectral maximum amplitude differ two times, while estimates of long-wave slope variance as much as ten times.
Keywords: brightness temperature, atmosphere radiation, accuracy of remote sensing methods, NRRS method, gravity-capillary waves spectrum, field experiment
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