Title :
Digital generation of signal quadrature for synthetic aperture radiometers
Author :
Gatlin, James A. ; Lawrence, Wes
Author_Institution :
NASA Goddard Space Flight Center, Greenbelt, MD, USA
Abstract :
A study of digital signal processing techniques for generating signal quadrature in synthetic aperture radiometers with difference equations derived from digital systems using finite impulse response (FIR) filters is presented. In one system block diagram, the FIR is a low pass filter; and in the other, the FIR is a Hilbert transform. It is shown that both systems reduce to the same set of difference equations. The effect of reducing the number of coefficients in the FIR is studied and characterized through the use of test data
Keywords :
FIR filters; Hilbert transforms; atmospheric measuring apparatus; atmospheric techniques; geophysical equipment; geophysical signal processing; geophysical techniques; microwave detectors; radiometers; radiometry; remote sensing; Hilbert transform; SHF; atmosphere; difference equations; digital generation; digital signal processing; finite impulse response filter; geophysical measurement technique; land surface; low pass filter; measurement technique; meteorology; microwave radiometry; remote sensing; signal quadrature; synthetic aperture radiometer; system block diagram; terrain mapping; Difference equations; Digital filters; Digital signal processing; Digital systems; Finite impulse response filter; Low pass filters; Radiometers; Signal generators; Signal processing; Transforms;
Conference_Titel :
Geoscience and Remote Sensing Symposium, 1999. IGARSS '99 Proceedings. IEEE 1999 International
Conference_Location :
Hamburg
Print_ISBN :
0-7803-5207-6
DOI :
10.1109/IGARSS.1999.773461
