Sovremennye problemy distantsionnogo zondirovaniya Zemli iz kosmosa, 2017, Vol. 14, No. 3, pp. 118-127
L-band radiometer-polarimeter
S.V. Marechek
1 , M.T. Smirnov
1 1 V.A. Kotelnikov FIRE RAS, Fryazino, Moscow Region, Russia
Accepted: 02.06.2017
DOI: 10.21046/2070-7401-2017-14-3-118-127
The work is devoted to the development of a microwave radiometer for measuring parameters of the underlying surface in remote sensing of “atmosphere – Earth surface” system. A technique for processing the measured microwave radiation signals to calculate four Stokes polarization parameters is proposed. The technique is based on interference processing of two orthogonally polarized input signals. The signals from the antenna output are fed directly to the vector processing unit. The radiometer has four channels for amplifying the signals from the outputs of the interference processing unit. The channels contain all the components of the Stokes parameters. No signal correlation processing at subsequent stages is required. The main advantage of using the interference technique against the correlation technique is that fundamentally passive linear element is used – vector power adder – divider. The use of the interference system makes it easier and less expensive to implement the amplification and processing paths of the radiometer. A mathematical model describing all transformations of the measured signals is developed. Based on the proposed technique, L-band radiometer-polarimeter was made. The descriptions and functional diagrams of the main units of the microwave radiometer are presented. The radiometric channels are made according to the classical scheme of modulation radiometer. The procedure for internal calibration of the radiometer and the method for obtaining the parameters of the polarization ellipse are proposed.
Keywords: radiometer, Stokes parameters, remote sensing, radiative characteristics, underlying surface, the Earth's atmosphere, temperature, humidity, satellites
Full textReferences:
- Bass F.G., Fuks I.M., Rasseyanie voln na statisticheski nerovnoi poverkhnosti (Scattering of waves on statistically rough surface), Moscow: Nauka, 1972, 424 p.
- Marechek S.V., Interferentsionnyi radiometr-polyarimetr (Interferometric radiometer-polarimeter), Instruments and Experimental Techniques, 2008, No. 4, pp. 64–70.
- Marechek S.V., Perspektivy ponizheniya riskov putem ispol'zovaniya radiometrov L-diapazona v sistemakh monitoringa raionov zarozhdeniya tropicheskikh tsiklonov (Prospects of risk mitigation by usage of L-band radiometers in systems of monitoring of tropical cyclones origin areas), Ekologicheskie sistemy i pribory, 2011, No. 1, pp. 24–29.
- Germain K.St., Poe G.A., Gaiser P.W., Polarimetric emission model of the sea at microwave frequencies and comparison with measurements, Progress In Electromagnetics Research, 2002, PIER 37, pp. 1–30.
- Koistinen O., Lahtinen J., Hallikainen M., Comparison of analog continuum correlators for remote sensing and radio astronomy, IEEE Trans. Instrum. Meas., 2002, Vol. 51, pp. 227–234.
- Rotbøll J., Søbjærg S.S., Skou N., L-band polarimetric correlation radiometer with subharmonic sampling, IEEE Int. Geosci. Remote Sensing Symposium, Sydney, Australia, Proc. 2001, pp. 1571–1574.