Us4041487a low elevation angle radar tracking system. Lcm was employed to model the land and sea clutter for notional s, c and x band radars at the height of the sea breeze. Book low angle radar land clutter measurements and. On clutter ranks of frequency diverse radar waveforms yimin liu, member, ieee, le xiao, xiqin wang, and arye nehorai, fellow, ieee abstractfrequency diverse fd radar waveforms are attractive in radar research and practice. A necessary reference for all radar engineers or analysts including many levels of managers, advisors and decision makers in the u.
For land clutter fw is equal to zero, whereas fw is proportional to the radial velocity of the weather clutter. Save up to 80% by choosing the etextbook option for isbn. Lcm is a robust, combined land and sea clutter model based upon sitespecific radar reflectivity and topography. It unifies and integrates results which should enable prediction of land clutter effects in surface radar, needed for low flying aircraft. Low angle radar land clutter measurements and empirical. They are the grazing angle, surface roughness, and the radar wavelength. To improve radar performance, a measure called radar cross section is calculated. Fusion of distributions for radar clutter modeling dtic.
The simulation of ground clutter based on dem is studied. Pdf evaluation of radar detection performances in low. We can use this kind of radar in sea and ground environments. Radars for the detection and tracking of cruise missiles. Three factors affect the amount of clutter in the radar beam. The sources and methods for receiving of the initial data for modeling are analyzed and described. Pdf modeling the amplitude distribution of radar sea clutter. Radar land clutter constitutes the unwanted radar echoes returned from the earths surface that compete against and interfere with the desired echoes returned by targets such as aircraft and other moving and. Cpa is a good identifier of clutter echoes since it is a metric of the primary characteristic of groundclutter echo from stationary targets. Finally i can also read the read bendix king kfc 200 autopilot manual pdf i was looking for this.
Directly useful in both military dod and civilian faa applications. K8430 za advances in the realtime simulation of synthetic clutter for radar. The complex gaussian process is a reasonable model for sea clutter in a low resolution maritime radar system. The results show radar clutter can be mitigated either by reducing the ground area illuminated by the antenna, in the case of surface clutter, or by reducing the pulse duration, in the case of volume clutter. Modeling of radar land clutter map for small grazing angles. A sitespecific model of radar terrain backscatter and. Efficient methods of clutter suppression for coexisting land. On the use of lowcost radar networks for collision warning. Finally, a radar network has been developed to demonstrate that the use of low cost olfmcw radar transceivers in a collision warning application is a feasible alternative. Traditionally, maritime surveillance of small targets is conducted from low. A radar set for providing accurate low elevation angle tracking of targets by means of controlling the magnitudes of radar detection level which are sequentially switched so that either of a pair of beams is greater in magnitude than is used for two beam tracking. Lband vv polarisation perspective executive summary radar clutter is defined as unwanted echo. Clutter detection in pulsedoppler radar systems ahmet gung or m. When the antenna scans at low elevation angles, the clutter.
Shadowing due to terrain height variations and cultural featuresbecome very marked. Spatial aspects of sea and land clutter from s, c, and x. This doppler shift is an important method of removing unwanted signals in the signal processing part of radar system. This function uses billingsleys model in the calculation. Rcs glints of wind turbine blades are up to 30,000sqm.
On clutter ranks of frequency diverse radar waveforms. In university engineering courses, the emphasis usually is on the basic tools of the electrical engineer such as circuit design, signals, solid state, digital processing, electronic devices, electromagnetics, automatic control, microwaves, and. Such echoes are typically returned from ground, sea, rain, animalsinsects, chaff and atmospheric turbulences, and can cause serious performance issues with radar systems. Barrie billingsley lincoln laboratory massachusetts i.
When i have been looking everywhere not met, but in this blog i have finally found free. Figure 15 from radars for the detection and tracking of. Results show that sea clutter exhibits very different spectral characteristics at higher frequencies compared to those at low frequencies. So, by improving the clutter model, we should get a more realistic, and. Radar land clutter constitutes the unwanted radar echoes returned from the earths surface that compete against and interfere with the desired echoes returned by targets such as aircraft and other moving.
First of all, the target scattered power, determing by the radar crosssection rcs, is comparable or less than the clutter intensity. Radar is an important example of an electrical engineering system. Clutter echoes can be many orders of magnitude larger than target echoes. By combining two typical fd waveforms, the frequency diverse array fda and the stepped. Land clutter models for radar design and analysis ieee.
Radar sea clutter modelling and applications instructors. For smooth terrain and sea surface and low grazing angles. Low angle radar land clutter low angle radar land clutter pdf online free. Barrios abstract radar clutter in a nonstandard atmosphere usually is modeled based on a single grazing angle. Home package low angle radar land clutter measurements and empirical models pdf. In a high resolution radar system however, there may be only a. The engagementanalysis computer program combines the measurement data and defensesystem models to predict the survivability of the air vehicle in the defensesystem engagement scenario. Sinan gezici august 2010 among various types of radar systems, the pulsedoppler radar is the most widely used one, especially in military applications. By carefully combining the radar backscatter over azimuth and grazing angles to increase the. The vvpolarized wband backscattering behavior of homogeneous ground clutter has been investigated by measuring the radar cross section per unit area of 116th scale rough surface terrain in a 1.
Real aperture array radar, imaging radar, and passive and multistatic radar. The billingsley icm model the billingsley model for the power spectrum due to internal clutter motion icm, also called intrinsic clutter motion of windblown radar clutter, which is mentioned on pp. Radar land clutter constitutes the unwanted radar echoes returned from the earths surface that compete against and interfere with the desired echoes. Tk 6575 m52 mimo radar signal processing edited by jian li, petre stoica. Page 1 of 10 notes on the billingsley icm model mark a. A concise handbook for radar design and performance analysis g. Radar land clutter constitutes the unwanted radar echoes returned from the earths surface that compete against and interfere with the desired echoes returned by targets such as aircraft and other moving and stationary targets. The accuracy of the prediction is verified by using airborne experimental captivecarry tests. Outline introduction history of clutter rejection noncoherent mti impact of the digital revolution moores law mti clutter cancellation general description. Radar is a detection system that uses radio waves to determine the range, angle, or velocity of objects. Clutter model for vhf sar imagery julie ann jackson and randolph l. Icm arises when wind blows on vegetation or other clutter sources.
Calculate the rcs of a clutter patch and estimate the clutter tonoise ratio cnr at the receiver. The lowaltitude target detection and land clutter rejection associate with. The model employs both the billingsley land clutter model 3, and the git sea clutter. Returns from geographical land masses are generally stationary, however, the effect of wind on trees etc means that the target can introduce a doppler shift to the radar return. Radar clutter modeling and analysis pdf free download.
A littoral clutter modelling approach that derives threedimensional refractivity profiles from mesoscale numerical weather prediction msnwp, applies them to parabolic equation pe propagation models, and combines them with empirical surface clutter reflectivity models to generate a more realistic model of surface clutter, is described. Below is an example radar images using the lowest tilt angle 0. Future development will focus on sea clutter, and clutter for moving radar platforms, such as airborne radar systems. Clutter modeling and analysis introduction in the last session we saw how probabilistic models of targets and clutter could be used to calculate radar performance. At the lower grazing angles, multipath interference produces lower re. First, the reflection coefficient considering the curved earth effect is derived. Urban mountains foresthigh relief terrain slopes 2. The likelihood ratio is the priorposterior pdf ratio of amplitude of the echo from the target. Fusion of distributions for radar clutter modeling erik p. Effects of compound k distributed sea clutter on angle measurement of. Here, collision geometry is assumed in which the radar and target aircraft fly straightline paths toward an intercept point. In principle, all that is required to estimate the radar return backscatter from a region of clutter is a knowledge of the volume or surface illuminated and the echo per unit volume.
Models of land clutter vs grazing angle, spatial distribution and temporal distribution. Lowangle radar land clutter 1st edition 9781891121166. Physical scale modeling the millimeterwave backscattering. Feb, 2016 radar systems course 44 clutter 1112009 ieee new hampshire section ieee aes society references 1. The low angle radar empirical land clutter model, designed by j.
Fabrication of scale model rough surfaces an array of 27 ground planes was fabricated for the clutter. Littoral model, radar clutter, radar modeling, radar propagation, terrain effects. Pdf merging radar data with geographic data for visual land. The advent of the modern cruise missile, with reduced radar observables and the capability to fly at low altitudes with accurate navigation, placed an enormous burden on all defense weapon systems.
The clutter may fill a volume such as rain or be confined to a surface like land. Lowangle radar land clutter pdf free download epdf. Radar seaclutter at low grazing angles iet journals. Analysis of high grazing angle seaclutter with the kk. P billingsleyicmfd,fc,wspeed calculates the clutter doppler spectrum shape, p, due to intrinsic clutter motion icm at doppler frequencies specified in fd. A simulation method for studying effects of sitespecific clutter on.
The performance of detection can be improved via utilizing the multipath echoes. Billingsley, low angle radar land clutter, iet, 2002. Table 2 shows the wind and wave ground truth for the two days. Radar spacetime processing for rangefolded spreaddoppler. It actually solves the problem of low angle radar land clutter by showing the reader how to design and predict the performance of radars that operate in situations where land clutter is prevalent.
The result of 20 years of research at mit lincoln laboratory, this book is of the most significant technological consequence for the industry. General concepts radar cross section rcs rcs per unit illuminated area. The clutter encountered in low grazing angle situations is generally a non gaussian impulsive noise resulting in a mismatching of the classical radar detector adjusted to the detection threshold. Blasch air force research lab 2241 avionics cir wpafb, oh 45433. Banks dissertation submitted in partial ful llment of the requirements for the.
Doppler ambiguities and blind speed effects mti improvement factor mti. In this paper, we continue with the assumption of 10 and 11 that the weather and land clutter have the same type of autocorrelation function but with different doppler frequencies. The simulation of ground clutter is the key and knot problem in radar simulation system. Antonia papandreousuppappola, chair chaitali chakrabarti daniel bliss narayan kovvali. It actually solves the problem of low angle radar land clutter by showing the reader how to design and predict the performance of radars that operate in situations where land clutter prevalent. Billingsleys intrinsic clutter motion icm model matlab. You can be the book low angle radar land clutter measurements and empirical models system to do them send you was based. Clutter is a term used for unwanted echoes in electronic systems, particularly in reference to radars. Merging radar data with geographic data for visual land clutter source recognition conference paper pdf available in proceedings of spie the international society for optical engineering. Normal resolution will merge signals together this will give total blindness in the whole area of windfarms resolving the radarwind farms interaction, geoff butler bae 2005 the effects of wind turbine farms on atc radar, awcead72665trials may 2005 glint from blades. Lowangle radar land clutter measurements and empirical models j. Lowangle radar land clutter 1st edition by billingsley, j. In 1982, to understand this phenomenon better and to improve prediction models, lincoln laboratory built a propagation measurement instrumentation module that could be conveniently carried on a. The grazing angle is the angle from the surface of the earth to the main axis of the illuminating beam, as illustrated in fig.
Lusty lawyers and their innocent interns vol 1 pdf online free. Synthetic aperture radar sar is an invaluable tool for detection of ground moving. An analysis of sea clutter data obtained in conditions typical of sea state 2 at x, s, l bands, uhf and vhf is presented. Lee department of electrical and computer engineering duke university date. Figure 1 from radars for the detection and tracking of. Radar systems engineering lecture 12 clutter rejection. The low altitude target detection and land clutter rejection associate with number of difficulties 1,2.
This solution avoids selfinterferences while maintaining the hardware simplicity and performance of an isolated lfmcw sensor. Significant gaps remain in the published data, especially for groundbased radars viewing the terrain at grazing incidence. Low angle radar land clutter measurements and empirical models pdf. Chan, spectral characteristics of low angle radar ground clutter defense research establishment ottawa, tech. An array of scale model ground planes was fabricated with the appropriate roughness to model smooth to rough soil terrain. Nov 06, 2014 as the inversions set in, anomalous propagation takes hold thanks to superrefraction and ground clutter lights up on the various radar sites going east to west with the setting sun. Every element of the engagement process, referred to as the kill. The littoral clutter model lcm is used as a basis for the sidelobe clutter modeling described in this paper. Advances in the realtime simulation of synthetic clutter. Rosenberg, radarconf 2015, johannesburg, south africa. Shengchou lin radar system design pulsed doppler power spectrum f d 2v c cos. Pdf mapping of weather radar ground clutter using the. Li shasha automation institute, harbin engineering university, harbin, heilongjiang province, china. A motion parameter estimation method for radar maneuvering.
Scattering, the k distribution and radar performance. Ground clutter mitigation with moving target indication mti. For lowgrazing angles there is also the concern of. In these bands, phenomena associated with clutter 2 interfere with radar performance for ship and terrestrial vehicle detection. Echoes from land or sea are examples of surface clutter. Lowgrazing angle detection in compoundgaussian clutter with. Thus, the combination of a low tilt angle and an inversion at and near the earths surface promotes an abundance of ground clutter. This paper focuses on the target detection in low grazing angle using a hybrid multipleinput multipleoutput mimo radar systems in compoundgaussian clutter, where the multipath effects are very abundant. This example shows the design of a moving target indication mti radar to mitigate the clutter and identify moving targets. Statistical land clutter modeling for airborne radar. F db frequency band terrain type vhf uhf lband sband xband. Radar spacetime processing for rangefolded spreaddoppler clutter mitigation by william w. Radar systems course 44 clutter 1112009 ieee new hampshire section ieee aes society references 1.
A study of ground clutter suppression at the chill doppler weather. Land clutter reflectivity has been described in the literature for many types of terrain, viewed by radars of different frequencies at different grazing angles. Land clutter models for radar design and analysis abstract. Low angle propagation measurements propagation of radar signals can affect radar target and clutter returns, especially at low frequencies e. Mapping of weather radar ground clutter using the digital elevation model srtm. Billingsley solves the problem of radar land clutter, where echoes from the earths surface interfere with radar target echoes. Please note that currently the pdf files are windows only, but if you use a different operating system, we can still provide you with the file. Shengchou lin radar system design pulsed radar noncoherent pulsed radar no reference signal. Professor michael raymond inggs department of electrical engineering university of cape town april 2016 a minor dissertation submitted to the department of electrical engineering, university of cape town, in partial ful. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. For the exact correlation between the model and real data we combine the. Jul 22, 2004 the technique of radar clutter map elaboration for land backscattering at the frequency band of 3 100 ghz for small grazing angles is proposed taken into consideration the terrain relief and vegetation.