Processing of signum coded sar signal: theory and experiments

Franceschetti, G.; Pascazio, Vito; Schirinzi, Gilda

doi:10.1049/ip-f-2.1991.0025

Cited by 58 publications

(42 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…+ n,(t) +jn,(t) (9) where n,, n, are the real and imaginary part of the noise, one the Hilbert transform of the other and with identical statistical properties.…”

Section: (4)mentioning

confidence: 99%

See 1 more Smart Citation

Time-domain convolution of one-bit coded radar signals

Alberti

Schirinzi

Franceschetti

et al. 1991

IEE Proc. F Radar Signal Process. UK

Self Cite

View full text Add to dashboard Cite

The compression of the radar signal is considered when the latter and the reference function are both coded at one bit. A sound theory is provided, which describes the performance of hardlimited signals for pulse compression, the effect of noise and the opportunity for fast convolution methods in time domain. The theory is supported by numerical examples on simulated data. Preliminary considerations regarding the use of dedicated hardware are included. IntroductionAs is well known, convolution is a very important tool in studying the evolution of physical processes in linear systems of known unit response function. Its use is very common in a wide field of applications such as system control, signal processing and communication theory. Convolution processes can be conventionally performed in the time domain by means of analogue lumped circuits. Development of digital techniques over the years has increased the use of digital processors to accomplish this operation. When these techniques are used, convolution is very eficiently performed in the frequency domain by means of fast Fourier transform (FFT) codes; in contrast, time domain digital convolutions are time consuming and less eficient. Time domain can compete with frequency domain digital convolution if the signal to be processed is somewhat simplified.It has been known for many years that a band-limited (BL) continuous signal can be completely recovered by the knowledge of its zeros [l-31. Real as well as complex zeros are present in general, while only real zeros are immediately detectable via the zero crossing of the function considered. However, there are invertible mappings [4, 51 that convert BL into RZ functions, i.e. functions whose zeros are wholly first order real. Sine wave addition accomplishes RZ conversion for periodic BL functions [4], thereby suggesting a practical tool for zero identification and successive function reconstruction. A similar result is obtained when a large noise is added to the signal [6, 71. Theory and experiments on signal recovery are also given in References 8 and 9.This hardlimiting issue is further developed by considering the convolution of the one-bit coded signal with a similarly one-bit coded reference function. In this way the signals to be processed reduce to binary sequencies, thus allowing the use of new fast convolution techniques based on elementary Boolean operations and a drastic reduction in required digital processor memory. This last feature is particularly important in the two-dimensional case, for which memory occupancy can be a very critical point. The latter observation is particularly relevant to synthetic aperture radar (SAR) applications. In addition, the processor architecture can be realised by simple, lightweight, inexpensive hardware [lo]. Signum coded chirp radarIn radar applications the pulse compression technique is widely used to obtain high range resolution together with large radiated energy [l 11. This is accomplished by using frequency or phase modulation to widen the signal bandwidth. ...

show abstract

“…+ n,(t) +jn,(t) (9) where n,, n, are the real and imaginary part of the noise, one the Hilbert transform of the other and with identical statistical properties.…”

Section: (4)mentioning

confidence: 99%

“…7 turns out to be [9] where ym is a known constant. For the first three terms we have [9] Thus the successive series terms of the convolution decay very rapidly.…”

Section: For M Even We Obtainmentioning

confidence: 99%

Time-domain convolution of one-bit coded radar signals

Alberti

Schirinzi

Franceschetti

et al. 1991

IEE Proc. F Radar Signal Process. UK

Self Cite

View full text Add to dashboard Cite

show abstract

“…Also, pixel phase is preserved with minor degradations (note the presence of the phase factor a in the trigonometric functions). As a matter of fact, ensemble average of n(´) recovers the original pixel re¯ectivity scaled by the factor s U (Franceschetti et al 1991(Franceschetti et al , 1999. 2.…”

Section: The Processing Chainmentioning

confidence: 99%

“…A new phase preserving time-domain signum coded SAR processor (SCSP) for real time operations has been recently proposed (Franceschetti et al 1991(Franceschetti et al , 1999. To overcome the hard computational requirements, SCSP is based only on data and reference function signum information and its hardware is realized by using shift registers and XNOR gates only.…”

Section: Introductionmentioning

confidence: 99%

“…To overcome the hard computational requirements, SCSP is based only on data and reference function signum information and its hardware is realized by using shift registers and XNOR gates only. In this case, only the zero-crossing information is preserved: most of relevant features are restored in the processing operations (Steinberg 1975, Franceschetti et al 1991, 1999. This is a ® rst step toward SAR processing in the operative simple time-domain.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Performance analysis of a novel time-domain real-time SAR processor

Franceschetti¹,

Iodice²,

Tesauro³

1999

International Journal of Remote Sensing

Self Cite

View full text Add to dashboard Cite

We test the performance of a new phase-preserving time-domain signum coded SAR processor (SCSP) aimed at real time operations. Raw signal interferometric pairs relevant to the Shuttle Radar Topography X-band Mission are simulated. A full result comparison between SCSP and conventional interferometric products is presented by using simulated canonical and real scenarios. The simulated canonical scene consists of a pyramid and three corner re¯ectors. The simulated real scene refers to the Mt Etna area in Sicily, Italy. Raw data are simulated both for ascending and descending orbits. Results show that SCSP combined with an iterative phase unwrapping algorithm can generate digital elevation models with good accuracy in spite of the higher phase noise level.

show abstract