Subaperture radar altimeter

A radar altimeter and aperture radar technology, applied in the field of altimeter, can solve problems such as restricting power utilization efficiency and measurement accuracy, and achieve the effects of improving accuracy, improving measurement accuracy, and improving effectiveness

Inactive Publication Date: 2007-10-03
NAT SPACE SCI CENT CAS
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  • Summary
  • Abstract
  • Description
  • Claims
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Problems solved by technology

However, DDA uses simple non-focus Doppler sharpening aperture synthesis and visual registration methods in the aperture s

Method used

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  • Subaperture radar altimeter
  • Subaperture radar altimeter
  • Subaperture radar altimeter

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Embodiment Construction

[0033] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0034] As shown in Figure 1, the sub-aperture radar altimeter of the present invention includes: timing unit 1, frequency modulation signal generating unit 2, up-conversion amplifying unit 3, power amplifier unit 4, antenna 5, low-noise amplifying unit 6, down-converting amplifying unit 7, phase detection unit 8 , digital processing unit 9 , echo tracking unit 10 , first mixer 11 , second mixer 12 and deskewing local oscillator 13 .

[0035] The timing unit 1 is used to provide a high-precision timing pulse signal, and its function is usually realized by a high-speed timing circuit.

[0036] The frequency modulation signal generating unit 2 is used to generate frequency modulation signals, and an active frequency modulation method is adopted in the present invention. This unit can be realized by DDS (Direct Digital Synthesis, Direct-Digital Sy...

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Abstract

The subaperture radar altimeter includes a timer unit, a frequency modulated signal unit, an up conversion amplifier unit, a power amplifier unit, an antenna, a low frequency amplifier unit, a down conversion amplifier unit, a phase detection unit, a digital processing unit, an echo tracking unit, a first mixer, a second mixer and a local oscillator. The digital processing unit completes the Fourier conversion of signal, fine range regulation, compression, coarse range correction and echo processing to obtain the echo waveform; and the echo tracking unit completes the estimation and calculation on altitude, echo strength and roughness parameters and the control on the other units based on the estimated result. Compared with delay Doppler altimeter, the present invention has improved azimuth compressing accuracy, raised emitting power utilizing efficiency, improved echo averaging effectiveness, and raised altitude measuring precision.

Description

technical field [0001] The invention relates to an altimeter, in particular to a sub-aperture radar altimeter. Background technique [0002] The radar altimeter is a kind of altimetry radar mounted on aircraft, satellites and other aircrafts, which can be used to measure the average height from the radar to the target surface, target fluctuation characteristics and backscatter coefficient and other parameters. [0003] Since its appearance in the 1970s, the spaceborne radar altimeter has played an important role in the observation fields of ocean, sea ice, and land ice with its unique advantages. The spaceborne radar altimeter plays an important role in the measurement of the ocean dynamic environment. It can measure the geoid fluctuation and gravity anomaly, invert the deep structure of the earth, detect large-scale ocean currents and mesoscale eddies, track the strength and weakness of ocean dynamic phenomena and Position migration, accurate measurement of changes in the ...

Claims

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Application Information

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IPC IPC(8): G01S13/90
Inventor 王志森许可杨双宝刘和光
Owner NAT SPACE SCI CENT CAS
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