Clutter core reference abstract classes and interfaces clutteractor the basic element of the scene graph cluttercontainer an interface for. The objective of this program was to prepare a clutter research plan for army air defense weapons that encompasses the anticipated methods of employment of these weapons, as well as the. Pdf sea clutter refers to the radar returns from a patch of ocean surface. A generalized clutter simulation software for the analysis. Radar returns are produced from nearly all surfaces when illuminated by radar. Unwanted signals in a search radar are generally described as noise and clutter. Radar returns from terrain or sea surface, or from rain, that interfere with the desired. Since radar clutter is generally highly correlated, the joint pdf cannot be derived by simply. Such echoes are typically returned from ground, sea, rain, animalsinsects, chaff and atmospheric. May 2016 the usage of this pdf file must comply with the. Earth curvature nomograph radar horizon line of sight there are limits t.
Radars operating in an open environment will receive returns from many sources. Radar systems course 4 clutter 1112009 ieee new hampshire section ieee aes society attributes of rain clutter rain both attenuates and reflects radar signals problems caused by rain lessen. The results show radar clutter can be mitigated either by reducing the ground area. The problem of clutter rejection when processing downlooking doppler radar returns from a low altitude airborne platform. Thus, a radar operating in a sea clutter environment works at a cfar. Pdf doppler radars can distinguish targets from clutter if the targets velocity along the radar line of sight is beyond that of the clutter.
The interference level can be characterized by the ratio of the received signal power, s, to the clutter power, c. Clutter can also be weatherrain, animals, chaff and atmospheric. For smooth terrain and sea surface and low grazing angles. Radar is an object detection system that uses electromagnetic waves to identify the range,altitude,direction. The most considerable clutter is weather clutter in an sband marine radar.
Radar clutter modeling and analysis pdf free download. Additionally, the pulse repetition frequency prf values necessary to obtain the desired. Clutter is spatially distributed and larger in physical size than the radar resolution cell. This is typically achieved by initial application of the radar equation to establish the relative power levels for a given situation of returns from targets and clutter. Andy norris, in radar and arpa manual third edition, 2014. Radar clutter mitigation techniques tecnico lisboa. An improved clutter suppression method for weather radars. Simulation of the radar ground clutter based on dem. Clutter data where to find for bc and how to convert to. Closets, flat surfaces, and spare bedrooms are magnets for clutter, but theres another area that doesnt get quite as much attention your computer.
Clutter makes the detection of wanted targets more difficult examples. On clutter ranks of frequency diverse radar waveforms. In the particular case of the compound k distribution model, the pdf of clutterplusnoise can be defined exactly 80. Palmer, senior member, ieee, boon leng cheong, tianyou yu, guifu zhang, senior. Suppression of lognormal distributed weather clutter. Noise was discussed earlier in detail concerning the radar basics. Theoretical predictions are compared with, measured values. 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. Clutter can be anything from trees, ground, ocean waves, anything that can produce an unwanted echo return to the radar.
Radar clutter radar clutter is unwanted echoes from the natural environment. This paper describes the implementation of an improved clutter suppression method for the multiple pulse repetition time prt technique based on simulated radar data. Calculate the rcs of a clutter patch and estimate the cluttertonoise ratio cnr at the receiver. Radar spacetime processing for rangefolded spreaddoppler clutter mitigation by william w. For example, when a target is located in the middle of a room with the same radar cross section rcs wall at 1 m or at 3 m, the nearby wall clutter amplitude is roughly larger than 79 db, based on the assumption. Pdf radar sea clutter suppression and target detection with. Dpcasar for clutter suppression, choosing it for its simplicity and effectiveness. If the return is greater than the detection threshold a target is declared. Realtime radar reflectivity calibration and monitoring.
Clutter mitigation decision cmd system for the nexrad orda john hubbert, mike dixon and scott ellis. There has been a long development of pdf models used to fit both real aperture radar and sar. In addition to reflections from objects of interest, usually known as targets, the radar signal will include backscatter. However, while dpcasar is robust in high clutter environments, the process of combining the two images to remove the. Pdf radar detection of aircraft on a particular scan depends in large measure on the clutter return from the targets range cell. The ground clutter returns are particularly large at low elevation angles and close range e. Radar clutter may be defined as unwanted signals in a search radar. When a radar detects targets on or above the sea surface, it has to.
Computes the probability density function pdf calculate the 95th percentile of reflectivity. Clutter model for vhf sar imagery julie ann jackson and randolph l. Clutter and interference tx rx target ground m u lti p a th d i r e c t p a t h c l u t t e r. On the use of auxiliary receive channels for clutter mitigation with phased array weather radars khoi d. Therefore, in competition with the return from an aircraft, there are many sources of unwanted signals. They are referenced by number in the supporting text and the full papers are. This signaltoclutter ratio, sc, depends on the target rcs, the amount of clutter illuminated, the clutter reflectivity and the effect of any clutter reduction techniques. 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. Radar systems course 3 airborne pd 112010 ieee new hampshire section ieee aes society outline introduction the airborne radar mission and environment clutter is the main issue different airborne radar missions pulse doppler radar in small fighter interceptor aircraft f14, f15, f16, f35 airborne, surveillance, early.
Waveform design for cognitive radar with deterministic. Collects the clutter area reflectivity for a given momentdaymonth. The manual sea clutter control adjusts the exact shape of this curve, according to how the. Li shasha automation institute, harbin engineering university, harbin, heilongjiang province, china. This signaltoclutter ratio, sc, depends on the target rcs. For a known clutter pdf, the pdf of clutterplusnoise will generally have to be calculated numerically. Papers presented in the thesis the papers listed below are the subjects of this thesis. Clutter refers to radio frequency rf echoes returned from targets which are uninteresting to the radar operators and interfere with the observation of useful signals. How radar detect, track, and attack through the clutter. Clutter is a term used for unwanted echoes in electronic systems, particularly in reference to radars. Reducing cross talk clutter on the radar screen you can reduce the appearance of clutter caused by interference from another nearby radar source, when the cross talk reject setting is on. Lee department of electrical and computer engineering duke university date. Clutter includes echoes from land, sea, weather, and animals. On the use of auxiliary receive channels for clutter.
Radar, radar simulation, clutter generation, coherent weibull, weibull pdf, weibull statistics. Keep the echoes with a reflectivity above 50 dbz and a frequency of occurrence superior to 50%. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. As mentioned in section 1, various clutter make detec tion of targets difficult in a radar. Radar is an acronym for radio detection and ranging. Moses the ohio state university, department of electrical and computer engineering 2015 neil avenue, columbus, oh 43210, usa.
A region of space filled with volume scatters will attenuate a radar wave m propagating. Frequent readers of this site know about all the most clutterprone areas of the home. Clutter mitigation decision cmd system for the nexrad orda. The algorithm includes the calculation of a pdf of sea clutter from an amplitude sar image, and use of the pdf and cfar to estimate a threshold t. Modeling the amplitude distribution of radar sea clutter mdpi.
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