Selection of Pulse Repetition Frequency in High-Precision Oceanographic Radar Altimeters

Ka, Min-Ho; Баскаков, А. И.

doi:10.1109/lgrs.2007.895679

Cited by 12 publications

(2 citation statements)

References 8 publications

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“…A conventional altimeter emits pulses at a pulse repetition frequency (PRF) of a few kHz, a rate expected to yield a sequence of echoes with little or no echo-to-echo correlation in the random variations in speckle [7], [14], [15], [16], [17], [18]. It forms the simple ("incoherent") average of the power received in a sequence of typically 50-100 echoes obtained over about 0.05 seconds, producing a "waveform" (see Fig.…”

Section: A Background and Previous Studiesmentioning

confidence: 99%

Removing Intra-1-Hz Covariant Error to Improve Altimetric Profiles of $\sigma^{0}$ and Sea Surface Height

Quartly

Smith

Passaro³

2019

IEEE Trans. Geosci. Remote Sensing

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Waveform retracking is the process by which a simple mathematical model is fitted to altimeter returns. Over the ocean the waveform location, amplitude and shape can be fitted by models with 3-5 free parameters, which may in turn be linked to geophysical properties of the surface of interest principally sea surface height, wave height and normalized backscatter strength (0 , related to wind speed). However random multiplicative noise, which is due to the summation of power from multiple differently orientated surfaces, produces errors in the estimation of these model parameters. Examination of the correlations among parameters estimated for each waveform leads to simple empirical corrections that reduce the waveformto-waveform noise in geophysical estimates, resulting in smoother (and more realistic) along-track profiles of 0 and sea surface height. These adjustments are fundamentally dependent upon the waveform model and retracker implemented, but when applied show improved agreement between near-simultaneous measurements from different altimeter missions. The effectiveness of these empirical adjustments is documented fully for MLE-4 retracking of the Jason-3 altimeter, with reduction in the 1-second variance of 0 by 97%. However, the ideas are applicable and beneficial for data from other altimeters, with small improvements in 0 for MLE-3 and for AltiKa at Ka-band, whilst reductions in range variance of ⇠40% are noted for most retrackers evaluated.

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Section: A Background and Previous Studiesmentioning

confidence: 99%

Removing Intra-1-Hz Covariant Error to Improve Altimetric Profiles of $\sigma^{0}$ and Sea Surface Height

Quartly

Smith

Passaro³

2019

IEEE Trans. Geosci. Remote Sensing

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“…The timing sequence design is also different in the airborne and space borne SAR [1,4]. Therefore, it is necessary to research the design method of pulse repetition frequency (PRF) [5,6] for highly squinted SAR mounted on maneuvering platforms [7][8][9].…”

Section: Introductionmentioning

confidence: 99%

A modified design method of pulse repetition frequency for synthetic aperture radar system based on the single point equivalent squint model

Liang

Zhang

et al. 2021

IET Radar Sonar & Navi

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Pulse repetition frequency (PRF) is an essential parameter in synthetic aperture radar (SAR). However, a small PRF value will cause spectrum ambiguity and a large value will increase the computational complexity. In highly squinted SAR imaging with maneuvering platform, the traditional PRF design methods used are airborne and space borne. SAR systems perform with a low precision because of the complex geometric configuration and system deviations. In order to adapt to the maneuvering platform SAR system, a modified design method of PRF is proposed in this paper. First, the azimuth spectrum of echoes is analyzed by establishing the SAR geometry base on the single point equivalent squint (SPES) model. Subsequently, the calculation of azimuth bandwidth is transformed into an optimization problem, and the lower limit of PRF is obtained by the Golden Section Method. Besides, the criteria of spectrum unambiguity and time sequence constraints in PRF design is also discussed in detail. Simulation experiments demonstrate the feasibility and accuracy of the proposed method.This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

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Enhancement of the sensitivity of the dual-frequency correlation radar over sea surface roughness in a small satellite

Баскаков

2013

Journal of Electromagnetic Waves and Applications

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Selection of Pulse Repetition Frequency in High-Precision Oceanographic Radar Altimeters

Cited by 12 publications

References 8 publications

Removing Intra-1-Hz Covariant Error to Improve Altimetric Profiles of $\sigma^{0}$ and Sea Surface Height

Removing Intra-1-Hz Covariant Error to Improve Altimetric Profiles of $\sigma^{0}$ and Sea Surface Height

A modified design method of pulse repetition frequency for synthetic aperture radar system based on the single point equivalent squint model

Enhancement of the sensitivity of the dual-frequency correlation radar over sea surface roughness in a small satellite

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