Method and apparatus for .DELTA.K synthetic aperture radar measu

Communications: radio wave antennas – Antennas – Balanced doublet - centerfed

Patent

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

343 5W, 343 172PC, G01S 1390

Patent

active

045090483

ABSTRACT:
A synthetic aperture radar (10) is employed for .DELTA.k measurement of ocean current from a spacecraft (11) without the need for a narrow beam and long observation times. The SAR signal is compressed (12) to provide image data for different sections of the chirp bandwidth, equivalent to frequencies f.sub.1 (t.sub.a,t), f.sub.2 (t.sub.a,t) . . . f.sub.n (t.sub.a,t), and a common area for the separate image fields is selected (14). The image for the selected area at each frequency is deconvolved (16) to obtain the image signals for the different frequencies (f.sub.1, f.sub.2 . . . f.sub.n) and the same area. A product of pairs of signals is formed (18, 20), Fourier transformed (22) and squared (24). The spectrum thus obtained from different areas for the same pair of frequencies f.sub.jk, f.sub.j+n,k are added (26) to provide an improved signal to noise ratio. The shift of the peak from the center of the spectrum is measured and compared (28) to the expected shift due to the phase velocity of the Bragg scattering wave. Any difference is a measure of current velocity v.sub.c (.DELTA.k).

REFERENCES:
patent: 4053886 (1977-10-01), Wright et al.
patent: 4101891 (1978-07-01), Jain et al.
patent: 4172255 (1979-10-01), Barrick et al.
Robert H. Stewart et al., "HF Radio Measurements of Surface Currents" Jun. 8, 1974, pp. 1039-1049, Deep Sea Research 1974, vol. 21.
Jain, A. (1977), "Determination of Ocean Wave Heights from Synthetic Aperture Radar Imagery," Applied Physics, vol. 13, pp. 371-372.
Schuler, D. L. (1978), "Remote Sensory of Directional Gravity Wave Spectrum and Surface Currents Using Microwave Dual-Frequency Radar," Radar Sciences vol. 13, pp. 321-331.
Plant, W. J. and Schuler, D. L. (1980), "Remote Sensing of the Sea Surface Using One- and Two-Frequency Microwave Techniques," Radar Sciences, vol. 15, pp. 605-615.

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Method and apparatus for .DELTA.K synthetic aperture radar measu does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Method and apparatus for .DELTA.K synthetic aperture radar measu, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for .DELTA.K synthetic aperture radar measu will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-1093246

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.