The radio-frequency (RF) electromagnetic spectrum, extending from below 1 MHz to above 100 GHz, represents a precious resource. It is used for wide range of purposes, including communications, radio and television broadcasting, radionavigation, sensing. Radar fundamentally important use the (EM) in applications which include air traffic control, geophysical monitoring Earth resources space, automotive safety, severe weather tracking, surveillance defense security. Nearly all services have...

The successful optimisation of the detection performance maritime surveillance radars requires a detailed knowledge and understanding both forward- backscattering from ocean surface. Such an enables development suitable signal-processing techniques. paper is therefore divided into two parts, first being concerned with radar scattering environment second target detection. In part it shown, through analysis full-scale measurements, how amplitude correlation properties high-resolution...

This book examines the statistics of radar scattering from sea surface in terms their relevance to operating a maritime environment; including remote sensing , surveillance and targeting appliances. A lot work iss based on compound K-distribution model for amplitude clutter. In addition, addresses specification performance required by customers measurement systems supplied customers.

The compound K-distribution model for high resolution seaclutter is extended to cover the addition of thermal noise. Thismodel not only a good match real data but also allows thepulse-to-pulse correlation clutter returns be modeled. Thematching and analysis required target detectionprediction are described, together with some typical detectionresults.

In the paper radar detection of targets in sea clutter modelled by compound K-distribution is examined from a statistical viewpoint. Optimum performance determined for both fixed threshold and ideal constant false alarm rate (CFAR) receivers Swerling cases 0, 1 2. particular, dual binary integrators assessed. The model not only good fit to observed amplitude statistics over wide range conditions, but also allows temporal spatial correlation characteristics be accurately modelled. modelling...

This paper describes a new technique for modeling and simulating the coherent returns from radar sea clutter, based on compound K-distribution model clutter amplitude statistics. Using observations of recorded Doppler spectra, simple method is proposed characterizing temporal variations spectrum observed in single-range cell. It shown that simulations this can reproduce main statistical features real measurements.

In the paper radar detection of targets in sea clutter modelled by compound K-distribution is examined from a statistical viewpoint. Optimum performance determined for both fixed threshold and ideal constant false alarm rate (CFAR) receivers Swerling cases 0, 1 2. particular, dual binary integrators assessed. The model not only good fit to observed amplitude statistics over wide range conditions, but also allows temporal spatial correlation characteristics be accurately modelled. modelling...

This study is concerned with the characterisation of Doppler spectra from high range resolution X‐band radar sea clutter observed an airborne platform over grazing angles, 15° to 45°. It that when looking up or down wind there a strong correlation between mean shift and local spectrum intensity. When combined random fluctuations width, these characteristics give temporal spatial variability. behaviour has previously been in low angle data results confirm wider applicability models developed...

The detection performance of a cell-averaging CFAR detector is analysed for spatially correlated K-distributed clutter. In thermal noise or uniform clutter, the can be compared with that ideal fixed threshold, but an associated 'CFAR loss', quantified by increase in average signal-to-clutter ratio required to achieve given probability and false alarm. some types knowledge overall amplitude distribution alone not sufficient assess CFAR. particular, sea clutter may exhibit significant spatial...

Techniques for detection performance prediction maritime surveillance radars are described, with particular emphasis on the use of compound K-distribution model radar sea clutter. The paper first briefly reviews analytical methods deriving theoretical limits using models both clutter and targets. Next, it is shown how environment modelled design evaluation, whereby may adapt to this changing optimum target described. This followed by a description new method cell-averaging CFAR in real...

The compound K-distribution model for sea clutter previously described in the literature provides foundation a quantitative treatment of spatial and temporal correlation characteristics envelope returns. In paper is extended to cover clutter. relationship these physical basis described, methods their simulation are discussed. effects different radar range resolutions analysed theoretically results compared with observations on real data. Finally, techniques derived optimising resolution give...

Radar backscatter from the sea surface has a significant effect on radar systems operating in maritime environment. This study considers application of modelling clutter to design and development such systems, addresses sensitivity predicted performance choice model. The typical phases life-cycle system are described, along with how models used support development. Different types model reviewed some examples given comparison their performance. conclusion is that differences important...

The initial analysis of data collected during the airborne experiments has demonstrated passive radar operation, using commercial FM radio signals as illuminators opportunity, and these are believed to be first results this kind. have highlighted several practical techniques for improving system performance: multiple perspectives, optimal illuminator modulation bandwidth, looks over time.

The probability distribution of the radar backscatter is commonly used to determine threshold for separating targets from clutter. Analysis sea-clutter data collected at high grazing angles, between 15° and 45°, by Defence Science Technology Organisation (DSTO) Ingara fully polarimetric X-band has been extensively test models given a large number samples. focus this paper most appropriate model angle smaller samples in typical target detection scenario. For purpose, recently proposed...

One of the key requirements a radar system is to detect targets against background interference. This can be challenging problem in maritime domain when sea moves complex manner and characteristics are time-varying or nonstationary. Understanding clutter therefore essential developing effective robust detection schemes. The first part this tutorial provides details relevant statistical models from literature which typically used characterize clutter. Using these enables us represent...

Passive bistatic radar (PBR) research has traditionally focused on using a static ground based receiver for air target detection. Reported are the initial findings from novel airborne PBR experiment commercial FM transmissions between 88 and 108 MHz, as illuminators of opportunity. A two-channel system was designed, constructed installed light aircraft flown with intention detecting low altitude targets in vicinity London's Heathrow Gatwick airports. Analysis data shown that successfully...

This study is concerned with the assessment of models Doppler spectra, derived from high range resolution X‐band radar sea clutter observed an airborne platform over grazing angles, 15–45°. When looking up or downwind these represent strong correlation between mean shift and local spectrum intensity. combined random fluctuations width, characteristics give spectra a temporal spatial variability. The are used to predict statistics as function frequency compared original data. It also shown...

The ability to detect small targets in sea clutter is still an ongoing challenge, even for modern radar systems. Over the past decade, development of new waveforms and signal processing algorithms has been assisted by increasingly good understanding characteristics clutter. Nevertheless, many challenges remain robust models that span wide range conditions viewing geometries encountered practice. This paper describes current with some suggestions on how they can be overcome.

This paper explores the performance of cell-averaging CFAR (CA-CFAR) detectors in sea clutter, using compound K-distribution clutter model. The first section provides a brief introduction to is followed by description CA-CFAR configuration being investigated and definition loss. ideal given provide basis against which gain can be assessed. Then, loss noise developed analytically compared with equivalent simulation results for no spatial correlation range. Finally, investigates methods...

This paper first examines the physical source of sea clutter spikes from considerations oceanographic principles and electromagnetic scattering; it is shown how scattering theory can be used to predict characteristics discrete in backscatter sea. The also modelled statistically as extensions standard K-distribution model for clutter, proposed by K.D. Ward et al. (1990). In this paper, work (1990) extended include addition thermal noise parameters matched real data. Results are presented...