Amplitude domain analysis of strong range and Doppler spread radar echos

Vierinen, Juha; Lehtinen, Markku; Virtanen, Ilkka

doi:10.5194/angeo-26-2419-2008

Cited by 3 publications

(8 citation statements)

References 11 publications

(11 reference statements)

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“…Although the examples in this study only deal with coher- q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q qq q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q qq q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q ent targets, the considerations also apply for amplitude domain estimation of strong range and Doppler spread (incoherent) echos, such as the ones described in Vierinen et al (2008b). Examples of practical use cases include Lunar measurements, range spread meteor trail studies, and artificial ionospheric heating induced enhanced ion-and plasma-line echos.…”

Section: Discussionmentioning

confidence: 99%

“…The presentation here slightly differs from (Vierinen et al, 2008b). Instead of a Fourier series, we will use B-splines to model the target backscatter.…”

Section: Target Estimation Variancementioning

confidence: 99%

“…In practice, the number of model parameters that can be succesfully modeled with sufficiently small error bars depends on the signal to noise ratio. The estimation of strong range and Doppler spread echos is shown in Vierinen et al (2008b). Figure 2 shows an example theory matrix for a target range extent N r = 14 with N s = 8 spline guide points per range.…”

Section: Incoherent Targetmentioning

confidence: 99%

“…We have previously described a method for estimating range and Doppler spread radar targets in amplitude domain at sub baud-length range-resolution using linear statistical inversion (Vierinen et al, 2008b). However, we did not use codes optimized for the targets that we analyzed.…”

Section: Introductionmentioning

confidence: 99%

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Fractional baud-length coding

Vierinen¹

2011

Ann. Geophys.

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Abstract. We present a novel approach for modulating radar transmissions in order to improve target range and Doppler estimation accuracy. This is achieved by using non-uniform baud lengths. With this method it is possible to increase subbaud range-resolution of phase coded radar measurements while maintaining a narrow transmission bandwidth. We first derive target backscatter amplitude estimation error covariance matrix for arbitrary targets when estimating backscatter in amplitude domain. We define target optimality and discuss different search strategies that can be used to find well performing transmission envelopes. We give several simulated examples of the method showing that fractional baudlength coding results in smaller estimation errors than conventional uniform baud length transmission codes when estimating the target backscatter amplitude at sub-baud range resolution. We also demonstrate the method in practice by analyzing the range resolved power of a low-altitude meteor trail echo that was measured using a fractional baud-length experiment with the EISCAT UHF system.

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Section: Discussionmentioning

confidence: 99%

“…The presentation here slightly differs from (Vierinen et al, 2008b). Instead of a Fourier series, we will use B-splines to model the target backscatter.…”

Section: Target Estimation Variancementioning

confidence: 99%

Section: Incoherent Targetmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Fractional baud-length coding

Vierinen¹

2011

Ann. Geophys.

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“…We discuss the possibility of doing inversion analysis of echo amplitude data to solve for the scattering amplitudes instead of correlation properties of the target (Vierinen et al, 2008b). This way of analysis is advantageous with very narrow targets like meteor heads and narrow ionospheric layers.…”

Section: Introductionmentioning

confidence: 99%

Fast comparison of IS radar code sequences for lag profile inversion

Lehtinen¹,

Virtanen

Vierinen³

2008

Ann. Geophys.

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Abstract.A fast method for theoretically comparing the posteriori variances produced by different phase code sequences in incoherent scatter radar (ISR) experiments is introduced. Alternating codes of types 1 and 2 are known to be optimal for selected range resolutions, but the code sets are inconveniently long for many purposes like ground clutter estimation and in cases where coherent echoes from lower ionospheric layers are to be analyzed in addition to standard F-layer spectra.The method is used in practice for searching binary code quads that have estimation accuracy almost equal to that of much longer alternating code sets. Though the code sequences can consist of as few as four different transmission envelopes, the lag profile estimation variances are near to the theoretical minimum. Thus the short code sequence is equally good as a full cycle of alternating codes with the same pulse length and bit length. The short code groups cannot be directly decoded, but the decoding is done in connection with more computationally expensive lag profile inversion in data analysis.The actual code searches as well as the analysis and real data results from the found short code searches are explained in other papers sent to the same issue of this journal. We also discuss interesting subtle differences found between the different alternating codes by this method. We assume that thermal noise dominates the incoherent scatter signal.

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Inverse filtering of radar signals using compressed sensing with application to meteors

Volz

2012

Radio Science

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[1] Compressed sensing, a method which relies on sparsity to reconstruct signals with relatively few measurements, provides a new approach to processing radar signals that is ideally suited to detailed imaging and identification of multiple targets. In this paper, we extend previously published theoretical work by investigating the practical problems associated with this approach. In deriving a discrete linear radar model that is suitable for compressed sensing, we discuss what the discrete model can tell us about continuously defined targets and show how sparsity in the latter translates to sparsity in the former. We provide details about how this problem can be solved when using large data sets. Through comparisons with matched filter processing, we validate our compressed sensing technique and demonstrate its application to meteors, where it has the potential to answer open questions about processes like fragmentation and flares. At the cost of computational complexity and an assumption of target sparsity, the benefits over pulse compression using a matched filter include no filtering sidelobes, noise removal, and higher possible range and Doppler frequency resolution.Citation: Volz, R., and S. Close (2012), Inverse filtering of radar signals using compressed sensing with application to meteors,

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Amplitude domain analysis of strong range and Doppler spread radar echos

Cited by 3 publications

References 11 publications

Fractional baud-length coding

Fractional baud-length coding

Fast comparison of IS radar code sequences for lag profile inversion

Inverse filtering of radar signals using compressed sensing with application to meteors

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