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milstar: 1.Receiver dynamic range --------------------------------- Stat`ja Watkins-Johnson /razr. i postawshik priemnikow spionaza wj8617 w 80-90 godi/ http://www.triquint.com/prodserv/tech_info/docs/WJ_classics/vol14_n1.pdf http://www.triquint.com/prodserv/tech_info/docs/WJ_classics/vol14_n2.pdf http://www.triquint.com/prodserv/tech_info/WJ_tech_publications.cfm Dinamicheksij diapazon radara AN/FPQ-6 programmi Appolo -bolee 120 db Antenna -8.8 metra D ,5.4-5.9 ghz ,4.8 kwt srednej,3 megawatt impulsnoj moschnosti , dalnost bolee 60 000 km ,pri raz. +-2 metra ,IF-30 mgz,polosa signala -1.6 mgz http://en.wikipedia.org/wiki/AN/FPQ-6 http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19680003409_1968003409.pdf ljubitelskij priemnik smotri revue pri polose 400 herz , i ydalenii nesuchej signala pomexi 2000 herz blok. dinamicheskij diapazon -140 db ,chustw -138 db=0.028 microvolta http://www.elecraft.com/ 2. http://www.sandia.gov/RADAR/imageryka.html kollekzija image ot 35 ghz synthetic apperture radar razr.sposobnost' 4 inches -10 sm,100 millimetr polosa signala 2500 mgz Contact: To send feedback or request information about the contents of Sandia National Laboratories' synthetic aperture radar website, please contact: Nikki L. Angus Synthetic Aperture Radar Website Owner Sandia National Laboratories Albuquerque, NM 87185-1330 (505) 844-7776 (Phone) (505) 845-5491 (Fax) nlangus@sandia.gov http://www.sandia.gov/RADAR/movies.html kollekzija video s SAR Ku band i raz sposb 300 mm 3. -dbm microvolt conversion http://wa8lmf.net/miscinfo/dBm-to-Microvolts.pdf 0 dbm =224 millivolt dlja 50 ohm -47 dbm = 1 millivolt = 1000 microvolt -107 dbm = 1 microvolt -127 dbm = 0.1 microvolt -147 dbm = 0.01 microvolt -167 dbm = 0.001 microvolt = 1 nanovolt pri komnatnoj temperature tepl. schumi -174 dbm/ herz
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milstar: Minimalnaja polosa realizowannaja w woennix sistemax swjazi ( navigazija kak chastnij sluschaj swjazi) ###################################################################### 1. USA Navy very low frequency -50 bit/sek The Navy shore VLF/LF transmitter facilities transmit a 50 baud submarine command and control broadcast Polosa signala primerno 50 hertz http://www.fas.org/nuke/guide/usa/c3i/vlf.htm 2. Milstar/AEHF (zap 14.08.2010) -75 bit/sek .Polosa primerno 75 herz http://www.as.northropgrumman.com/products/aehf/assets/AEHF_datasheet_2010_.pdf 3. Military GPS Carrier track loop bandwidth = narrowband = 2 Hz http://wstiac.alionscience.com/pdf/Vol3Num4.pdf 4 .Sistemi troposfernoj swjazi .Toze chto i milstar/AEHF 75 bit/sec polosa 75 herz Est sowm. terminali troposkatter/sputnik http://www.gdsatcom.com/troposcatter.php W sluschae ochen wisokix pomex snizenie polosi s 50 hertz do 0.5 hertz ponizaet neobx.minimum signala na 20 db/100 raz/ -174db/hertz dlja polosi 1 herz pri 290 K -164 db dlja 10 herz -154 db dlja 100 herz --------------------------- " ... Gruschi ,w maximalnom tempe widwigajtes k Ygomonu" -Napoleon 1 iz 1024 wozmoznix fraz ,kotorie mozno peredat 10 bitnim pismom za 10 sek (polosa 1 hertz) ili 100 sek (polosa 0.1 hertz) w rezime naibolschej boewoj ystojchiwosti ( wisokaja ionizacija atmosferi ot serii podriwow yabch) #################################################
milstar: free space loss Milstar =- 210.8 db http://www.mitre.org/work/tech_papers/tech_papers_99/airborne_demo/airborne_demo.pdf A= -92.5 -20log(fd) f w gigaherz d w km 41000 km dlja maximum ydalenija GEO 20 ghz A=-210.776 db
milstar: 9S32 RLS The low noise receiver (noise factor 3 dB) uses an electrostatic amplifier tube that can withstand leakage powers of several hundred Watts without damage and with near-instantaneous recovery to full gain and sensitivity when the transmitted pulse ends. ***************************************************************************** 7volt na 50 omnuju antennu eto 1 watt na wxode priemnika 70 volt eto 100 watt [BR]http://www.ausairpower.net/APA-Russian-SAM-Radars-DKB.html#mozTocId551440 Thus, the loss attributed to solid-state protective devices commonly required in Western radars is also absent.
milstar: Dlja sravnenija s priemnikom S-300V ,kotorij rabotaet ,kogda na wxode bolee 100 volt - ########################################################################## Nize na linke sxema woennogo GPS priemnika ,kotorij rabotosposben pre prewischenii pomexi nad signalom na 120 db ########## http://nu-trek.com/nu-trek/rf-applications.html/#RF%20receiver ... no clipping nastupaet pri 0 dbm ili daze mensche 0 dbm = 0.224 volta
milstar: The front-end receiver amplifiers developed by Airborne Instrument Laboratory are cryogenically cooled parametric amplifiers, or paramps. These efficient paramps are major contributors to Haystack’s high radar sensitivity, achieving a system noise temperature of 35 K. ########### http://www.ll.mit.edu/publications/journal/pdf/vol12_no2/12_2widebandradar.pdf
milstar: http://www.phys.hawaii.edu/~anita/new/papers/militaryHandbook/rcvr_sen.pdf RECEIVER SENSITIVITY / NOISE
milstar: http://highfrequencyelectronics.com/Archives/May08/HFE0508_Cannata.pdf
milstar: http://callisto-space.com/en/products/miniature-cryogenic-low-noise-amplifiers.html mensche 1 kg Miniature Cyrogenic Low Noise Amplifiers The latest addition to Callisto’s range of cryo LNA products is our Miniature X-Band. This LNA is intended for use on tracking X-band ground station antennas operating around 8 GHz for reception. The LNA has two operating modes; normal and “turbo”. The difference between the two modes is the noise figure performance. In “turbo” mode the noise figure is significantly reduced compared to “normal” mode by cryo-cooling the LNA circuit. The intended application of this LNA is for critical data communications. By switching to the “turbo” mode the User can counter-act the effects of fading on his communications link by the improvement in his ground terminal G/T. When the link has returned to normal conditions the LNA can be switched back to “normal”, the cryo-cooler is switched off and the LNA circuits work at ambient temperature. A typical fade event can be caused by severe weather, for example. Another application for this dual mode LNA could be for ground stations used for in-frequent critical operations such as LEOP. Cooling of the LNA circuit to very low temperatures is achieved using a miniature Stirling cycle cryo-cooler. These high efficiency refrigerators have been developed to serve various applications most notably for Infra-Red detector cooling in military equipment. As such, these miniature cryo-coolers are designed for high reliability and robustness.
milstar: CIA priemnik http://watkins-johnson.terryo.org/Documents/Manufacturers/WJ/Data%20sheets/WJ-8617B%20data%20sheet.pdf
milstar: Miniature receiver with high dynamic range from Lincoln laboratory http://www.ll.mit.edu/publications/technotes/TechNote_mini-RFReceiver.pdf
milstar: http://www.gdsatcom.com/Electronics/Data%20Sheets/14368_C.pdf X-Band Low Noise Amplifiers LXA-7500 Series
milstar: http://www.callisto-space.com/en/products/compact-cryogenic-low-noise-amplifiers.html Noise temperatur 20°K
milstar: https://www.maximintegrated.com/en/app-notes/index.mvp/id/1929
milstar: In the case of a production line that produces satellite receivers, it may be quite easy to reduce the noise figure 1 dB by adjusting impedance levels or carefully selecting specific transistors. A 1dB reduction in noise figure has approximately the same effect as increasing the antenna diameter by 40%. But increasing the diameter could change the design and significantly raise the cost of the antenna and support structure http://cp.literature.agilent.com/litweb/pdf/5952-8255E.pdf Figure 1-2(a) shows an example situation at the input of an amplifier. The depicted signal is 40 dB above the noise floor: Figure 1-2(b) shows the situation at the amplifier output. The amplifier’s gain has boosted the signal by 20 dB. It also boosted the input noise level by 20 dB and then added its own noise. The output signal is now only 30 dB above the noise floor. Since the degradation in signal-to-noise ratio is 10 dB, the amplifier has a 10 dB noise figure
milstar: Ведь если корпус спутника неподвижен, то детали его, обращенные к Солнцу, могут нагреться (при малом контакте с корпусом) до 100° С, а части, находящиеся в тени, охладятся до -150° С и ниже http://epizodsspace.airbase.ru/bibl/zaytsev/sput-kosm/01.html ----------------- ! Шумовая температура антенны РЛС
milstar: This can be explained in Figure 7 which shows how the Friis equation is used to calculate the noise factor for cascaded gain stages. Notice that high gain in the first stage reduces the contribution of the noise factor of the second stage—the noise factor of the first stage dominates the overall noise factor. http://www.analog.com/media/en/training-seminars/tutorials/MT-006.pdf
milstar: http://www.satsig.net/noise.htm Noise temperature, Noise Figure (NF) and noise factor (f)
milstar: A 1.57-GHz RF Front-End for Triple Conversion GPS Receiver whose IF frequencies are 179, 4.7, and 1.05 MHz http://vergina.eng.auth.gr/electronicslab/files/tel_electr/00658621.pdf
milstar: 1st IF- Amplifier The first IF- Amplifier is a relatively narrowband amplifier with a high gain. The first IF has a relatively high value, e.g. 500 Megahertzes. This will cause a high effort of shielding measures. Automatig gain control measures will be realized here at least. Second converter The first IF gets down mixed with a fixed frequency from the 2nd Local Oszillator to the second IF. Second IF- Amplifier The second IF- Amplifier is a relatively narrowband amplifier with a very high gain. The frequency is a standard-value between 60 up to 75 Megahertzes. This frequency can be processed uncomplicated. The IF- Amplifier of a radar receiver determines the gain, signal-to-noise ratio, and effective bandwidth of the receiver. The typical IF amplifier usually contains from three to ten amplifier stages. The IF amplifier has the capability to vary both the bandpass and the gain of a receiver. The second IF- Amplifier is often a logarithmic amplifier. A large signal does not saturate the logarithmic amplifier; rather, it merely reduces the amplification of a simultaneously applied small signal. A small echo signal can often be detected by the logarithmic receiver when a normal receiver would be saturated. http://www.radartutorial.eu/09.receivers/rx07.en.html
milstar: Overview of Radar DMTI Processing The SPS-48E radar (Fig. 1) uses a triple conversion receiver. ########### The system is wideband until the second intermediate frequency (IF) conversion, where the individual beams are bandpass filtered and separated. Since three beams are used in the DMTI, there are three coherent oscillator frequencies (one for each beam) in the final conversion of the receiver (final IF is about 1.5 MHz). ################ A single analog-to-digital (A/D) converter is used for each beam. In-phase and quadrature (I/Q) data are developed based on samples that are spaced at multiples of 90° at the IF frequency. The interpolation filter develops the I/Q estimates from A/D samples (see the boxed insert, Intermediate-Frequency Sampling Technique). The I/Q data preserve the amplitude and phase of the IF radar return. The amplitude of the radar return is computed as ( ). I Q 2 2 + The phase of the return is computed as tan21 (Q/I). From pulse to pulse, a phase progression will be seen on moving targets due to Doppler, and no phase progression will be seen on stationary reflectors. It is this phase progression on moving targets that allows such targets to be separated from stationary reflectors (clutter). To remove clutter and pass targets, DMTI filters are employed in each beam independently. A bank of digital filters is used to cover the region between low velocity (small phase shift per pulse) and higher velocity (near 360° phase shift per pulse). Targets moving at speeds such that they present more than a 360° phase progression per pulse are said to be velocity ambiguous, since the radar pulse repetition interval causes aliasing. For example, a phase progression of 400° per pulse appears exactly as a phase progression of 40° per pulse. To avoid velocity blinds (i.e., targets moving at speeds such that their phase progression is 360° per pulse, thus appearing as 0° per pulse), the pulse repetition frequency is jittered on a burst-to-burst basis. This ensures that the phase progression presented by the target will vary on a burst-to-burst basis, and thus the target will not be velocity blinded on all bursts http://www.jhuapl.edu/techdigest/TD/td1803/roul.pdf Description The AN/SPS-48G is a long-range, three-dimensional (3D) Air Search Radar that will be installed on CVN, LHA, LHD, and LPD 17 class ships. The AN/SPS-48G is used to find full volumetric detection data for Ships Self Defense System and the Cooperative Engagement Capability (CEC), Air Intercept Control, Anti-Ship Cruise Missile detection including Low Elevation and High Diver targets, backup aircraft marshalling, and the new Hazardous Weather Detection and Display Capability. http://www.navy.mil/navydata/fact_display.asp?cid=2100&tid=1250&ct=2 AN/SPS-48E - Compared to the C variant, the SPS-48E has twice the radiated power, increased receiver sensitivity, four stage solid-state transmitter, half the components of a -48C and built-in testing for easier diagnostics. Originally developed as part of the New Threat Upgrade (NTU) Program to support the SM-2 Launch On Search (LOS) capability. 1975 under the Guided Missile Frigate Anti-Air Warfare Modernization Program. The AN/SPS-48E included a digital receiver and signal processor that could automatically detect and track very small targets, even when jammed. It was included in the New Threat Upgrade of the 1980s. The deployment of the AN/SPY-1 and the end of the Cold War led to the decommissioning of a large number of such ships, and many of these vessels AN/SPS-48 sets were reused on aircraft carriers and amphibious ships, where it is used to direct targets for air defense systems such as the Sea Sparrow and RIM-116 SAM missiles. Existing sets are being modernized under the ROAR program to AN/SPS-48G standard for better reliability and usability. ################# INTERMEDIATE-FREQUENCY SAMPLING TECHNIQUE To develop in-phase (I) and quadrature (Q) data, the SPS-48E radar uses an intermediate-frequency (IF) sampling technique with an IF bandwidth of approximately 400 kHz, IF center frequency of about 1.5 MHz, and analog-to-digital (A/D) sampling frequency of 6 MHz. There is a precise 4:1 relation between the IF sample frequency and the IF center frequency. If modulation effects across the received pulsewidth are ignored, the echo may be thought of as several cycles of a sine wave. The sine wave is sampled at four times its rate, i.e., every 90°. Therefore, alternate samples will be in quadrature with each other. To account for modulation effects across the pulse, one sample is defined to be “I”; two leading and two trailing samples are combined by the following equation to create the “Q” sample (s): 180° phase shift 90° phase shift Time Q ssss =− − + + 1 16 9 16 9 16 1 16 1234 Q I QI Q I Q s s Is s −− −− 1234 This technique provides accuracy acceptable for the clutter cancellation requirements of the SPS-48E lowelevation-mode DMTI. If higher clutter cancellation is required, a more elaborate finite impulse response filter for both the I and the Q channel is required. The advantage of the current technique is that I/Q data are developed with only a single A/D converter. The two baseband analog channels in a conventional receiver are not required, and aliasing due to channel gain mismatch is avoided. Amplitude modulation effects across the received pulse do, however, cause some degradation.
milstar: http://www.setron.de/_downloads/produkte/lt/238718f.pdf Fin 1 mhz 15msps SFDR -102 db ,Sinad-94.5 db
milstar: Динамический диапазон радара AN/FPQ программы Аполлон более 120 дб Антенна 8.8 метра диаметром C band 5.4-5.9 Ghz 4.8 квт средней мощности,3 мегаватта импульсной мощности промежуточная частота-30 мегагерц, полоса сигнала -1.6 мегагерц Дальность более 60 000 километров при разрешении +- 2 метра http://en.wikipedia.org/wiki/AN/FPQ-6 http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19680003409_1968003409.pdf
milstar: http://www.ee.fju.edu.tw/pages/032_faculty/sclin/lecture/Rada_System_Design/Chapter7.pdf If the first-stage network has adequate gain he noise figure of the total network is primarily determined by the first stage. #########################
milstar: There's a more important reason. I don't know for sure, but it's reasonable to assume the 8617B (or a derivative of it) meets the stringent TEMPEST signal leakage criteria. Two stories from the open literature demonstrate why one might be concerned with signal leakage from electronic equipment operated in sensitive locations. Both examples are from Peter Wright's book Spycatcher First, in the 1950's the French Embassy in London used a mechanical teleprinter and an on-line encryption device so that the 5-level Baudot signals sent outside the embassy were protected by high level encryption. However, careful examination of the encrypted data pulses showed small ghost images or glitches from the source un-encrypted signals. It was thus possible to read the signals as if they were completely unencrypted. (DeGaulle was President of France at the time and relations between the UK and France were frosty.) Second, the UK's MI5 counter-intelligence operation uncovered the operating frequencies used by the Soviet Union in the UK. By using a sensitive receiver, they were able to receive the local oscillator leakage and then by adding or subtracting the associated IF frequency, they could determine the frequency to which the embassy receiver was tuned. Similar techniques are said to be used in determining whether a household has an unlicensed TV set in the UK and with computer monitors it's possible to reconstruct an almost perfect pixel-by-pixel image of a monitor from some distance. The 8617B's signal leakage specification is less than -100 dBm, which is quite effective at making these sorts of recoveries difficult to impossible. http://www.cliftonlaboratories.com/wj-8617b_receiver_impressions.htm http://www.rfcafe.com/references/articles/wj-tech-notes/Rec_dyn_range1.pdf
milstar: http://www.sm5bsz.com/dynrange/qex/bdr.pdf Blocking dynamic range
milstar: ИСТРЕБИТЕЛЬ ШЕСТОГО ПОКОЛЕНИЯ СМОЖЕТ ДЕЛАТЬ "РАДИОФОТОГРАФИИ" САМОЛЕТОВ ПРОТИВНИКА 27 июля 2017 г., AEX.RU - Создаваемый в России новейший истребитель шестого поколения, который придет на смену Т-50, сможет делать радиолокационные "фотографии" самолетов противника и без участия человека определять их тип и вооружение. Об этом сообщил в интервью ТАСС советник первого заместителя гендиректора концерна "Радиоэлектронные технологии" (КРЭТ) Владимир Михеев. По его словам, КРЭТ разрабатывает для боевого самолета будущего радиофотонный локатор, уже имеется его экспериментальный образец и создается полномасштабный макет. Новый радар значительно превзойдет все существующие радиолокационные станции (РЛС) по мощности и диапазону. "Радиофотонный радар сможет видеть, по нашим оценкам, значительно дальше существующих РЛС. А так как мы будем облучать противника в беспрецедентно широком спектре частот, то с высочайшей точностью узнаем его положение в пространстве, а после обработки получим почти фотографическое его изображение - радиовидение", - рассказал Михеев. Он пояснил, что "это важно для определения типа (самолета - прим. ТАСС): сразу и автоматически компьютер самолета сможет установить, что это летит, к примеру, F-18 с конкретными типами ракетного оружия". Новый радар за счет своей сверхширокополосности и огромного динамического диапазона приемника будет иметь большие возможности по защите от помех. Также он дополнительно будет выполнять задачи радиоэлектронной борьбы (РЭБ), передавать данные и служить средством связи. На истребителе шестого поколения будет устанавливаться "мощная многоспектральная оптическая система, работающая в различных диапазонах - лазерном, инфракрасном, ультрафиолетовом, собственно оптическом, однако значительно превышающем видимый человеком спектр", отметил Михеев. Она дополнит радиофотонный радар. В марте 2016 года курирующий "оборонку" вице-премьер РФ Дмитрий Рогозин объявил о начале работ над истребителем шестого поколения. Как сообщил ТАСС в июне прошлого года глава дирекции программ военной авиации Объединенной авиастроительной корпорации Владимир Михайлов, опытный образец российского боевого самолета шестого поколения совершит первый полет до 2025 года. В предыдущем интервью ТАСС по теме истребителя шестого поколения Михеев рассказал, что новый самолет будет делаться в двух вариантах - пилотируемом и беспилотном. Новые истребители будут действовать в "стае", возглавляемой самолетом с летчиком на борту. Беспилотники смогут нести электромагнитные пушки, летать с гиперзвуковой скоростью, выходить в ближний космос. В этот раз Михеев добавил, что беспилотный вариант получит маневренность, недоступную для пилотируемых самолетов, у которых она ограничена возможностями человека переносить перегрузки. Хотя беспилотный и пилотируемый варианты истребителя шестого поколения будут делаться на одной базе, они будут отличаться не только составом вооружения и оборудования, но и внешне. КРЭТ разрабатывает для нового истребителя БРЭО и электромагнитное оружие в инициативном порядке. Так, концерн уже создал экспериментальный образец радиофотонного радара для этого самолета. Подробне
milstar: http://samonavedenie-raket.ru/sistemy-samonavedeniya/passivnaya-infrakrasnaya-sistema-samonavedeniya
milstar: During the early 1960s, the Jet Propulsion Laboratory developed a maser to provide ultra-low-noise amplification of S-band microwave signals received from deep space probes. This maser used deeply refrigerated hydrogen[citation needed] to chill the amplifier down to a temperature of four kelvin. Amplification was achieved by exciting a ruby comb with a 12.0 gigahertz klystron. In the early years, it took days to chill, and remove the impurities from, the hydrogen lines. Refrigeration was a two-stage process with a large Linde unit on the ground, and a crosshead compressor within the antenna. The final injection was at 21 MPa (3,000 psi) through a 150 µm (0.006 in) micrometer-adjustable entry to the chamber. The whole system noise temperature looking at cold sky (2.7 kelvins in the microwave band) was 17 kelvins. This gave such a low noise figure that the Mariner IV space probe could send still pictures from Mars back to the Earth even though the output power of its radio transmitter was only 15 watts, and hence the total signal power received was only -169 decibels with respect to a milliwatt (dBm).
milstar: http://publications.lib.chalmers.se/records/fulltext/155819.pdf
milstar: 2006 IPN Progress Report 42-165 May 15, 2006 A Dual-Channel 8- to 9-Gigahertz High-Electron Mobility Transistor (HEMT) Low-Noise Amplifier (LNA) Package for the Goldstone Solar System Radar E. M. Long 1 An existing dual-polarization 8- to 9-GHz high-electron mobility transistor (HEMT) low-noise amplifier (LNA) package with an input noise temperature of 15 K has been upgraded with state-of-the-art amplifiers, a lower-loss cooled wave- guide input, and a lower operating temperature closed-cycle refrigerator (CCR). The new system exhibits an input noise temperature of 4.4 K. This noise perfor- mance is now slightly better than that of the dual-channel maser currently used for radar in the Deep Space Network at DSS 14. ################################# This article will describe the changes made to achieve this performance. https://ipnpr.jpl.nasa.gov/progress_report/42-165/165C.pdf
milstar: https://www.youtube.com/watch?feature=endscreen&NR=1&v=D1A3SqlvvgM
milstar: We can now use commercial parts for A-D converters that enable us to do direct digital sampling,” says Douglas Reep, vice president and chief engineer of the Lockheed Martin Corp. radar systems segment in Syracuse, N.Y. “We are seeing a trend where we remove analog components from systems.” “Now we can almost digitize microwave signals without the down-convert,” says Jerald Nespor, Lockheed Martin senior fellow for radar development at the company’s facility in Moorestown, N.J. “We need A-D converters with sufficient sampling rates to do that. Everyone wants higher efficiency and more dynamic range, and we can do that with COTS technologies and innovative architectures.” ------------- typical levels of target echo returns are in the range of -90 to - 120 dbm http://www.scienpress.com/Upload/JCM/Vol%204_1_11.pdf
milstar: http://www.navair.navy.mil/nawcwd/ewssa/downloads/NAWCWD%20TP%208347.pdf
milstar: http://www.northropgrumman.com/Capabilities/AWACSAPY2/Documents/AWACS.pdf
milstar: http://www.arilissone.org/uploads/contenuti/vgo/Absolute%20limits%20of%20NF%20for%20Max%20Clip%20Level%20of%20a%20receiver%20RX.pdf
milstar: achieving an SNR of 72 dBFS for a -1 dBFS single tone input signal at 190 MHz requires the RMS jitter to remain below 236 fs The SP16160CH1RB subsystem design uses an input bandwidth of 20 MHz centered at an IF frequency of 192 MHz and a sampling rate of 153.6 MSPS. By addressing the challenges of interfacing to high-speed data converters in basestation applications, the subsystem design achieves a typical Nyquist-band SNR of 71 dBFS and SFDR greater than 82 dBFS for a -1 dBFS tone. Third order modulation products that fall in-band during a two-tone test are less than -91 dBFS for a composite signal with a 1 MHz spread and combined -4 dBFS peak-to-peak amplitude. Using a surface acoustic wave (SAW) filter and CMOS buffer, the SP16160CH1RB demonstrates the effective broadband noise-reducing solution shown in Figure 3 https://www.wirelessdesignmag.com/article/2010/02/wireless-basestation-design-challenges-using-high-speed-16-bit-adcs
milstar: http://www.highfrequencyelectronics.com/Sep08/HFE0908_S_Crean.pdf For example, consider an ADC with the following speci- fications: Sample rate: 120 MHz SNR @ 120 MHz: 76 dB LPF bandwidth: 2 MHz The SNR after processing gain is improved to approxi- mately 90 dB: Hence, by utilizing a high sampling rate relative to the signal bandwidth, we can operate over a dynamic range greater than the inherent SNR Symtx Inc. has implemented a dual ADC scheme to increase digitizer dynamic range as shown in Figure 3. The design uses a high-gain channel to process low-level sig- nals and a low-gain channel to process high-level signals, with simultaneous sampling of both channels in parallel. The gain difference between the high-level and low level ADCs is compensated with an appropriate n -bit left shift to give the correct scaling. A DSP after the two ADCs then selects the correct ADC output, adjusts for gain, and merges the two to create a 20-bit word with the desired dynamic range.
milstar: The Weather Surveillance Radar, 1988 Doppler (WSR-88D), also known as NEXRAD, is the most advanced operational weather radar in the world. The fleet of 160 WSR-88D radars operate 24/7 to support the weather warning and forecast missions of the National Weather Service, FAA and DoD. Additionally, real-time radar data is made available to the nation’s academic and commercial weather enterprise. Pictured to the left is the tower, which houses the antenna (inside the radome). https://www.roc.noaa.gov/WSR88D/Engineering/NEXRADTechInfo.aspx Type: S-band, coherent chain (STALO/COHO), line modulator, klystron tube amplifier (53 dB gain typical) Frequency: 2700 to 3000 MHz Average Power: 300 to 1300 watts Pulse Widths: 1.57 and 4.71 microseconds (-6 dB points) PRF short pulse: 318 to 1304 Hz PRF long pulse: 318 to 452 Hz Phase noise (system): phase and amplitude stability better than -57 dBc, -60 dBc system goal Short pulse output spectrum: -40 dB BW is 12.4 MHz, (-80 dB at +/- 62 MHz), -80 dB at +/- 19.6 MHz for congested areas(congested areas require transmitter output bandpass filter) Antenna characteristics- Type: Parabolic dish (28 feet in diameter) with center feedhorn Polarization: Dual Pol (simultaneous horizontal and vertical transmit/receive) Gain at 2850 MHz: 45.5 dB (including radome loss) Beamwidth at 2850 MHz: 0.925 deg First sidelobe: -29 dB (others less than -40 dB beyond 10 deg) Radome: fiberglass foam sandwich frequency tuned, 39 foot truncated sphere Radome two way loss: 0.24 dB at 2850 MHz Type: Coherent (stalo/coho), first downconvert to IF Detection: digital IF with 16 bit analog to digital conversion of IF signal at 100 MHz Digital Matched Filter BW: 625 kHz, short pulse, 204 kHz, long pulse Dynamic Range: 93 dB minimum required Intermediate Frequency: 57.55 MHz System noise figure: 270K (2.7dB) Receiver Noise: -114dBm (Short Pulse), -118dBm (Long Pulse) Referenced to Antenna Port. Front end interference rejection filter: 0.5 dB BW: 700 kHz, 30 dB BW: 50 MHz, 60 dB BW: 200 MHz Point target detection RCS = 4 cm2 at 100 km ###################
milstar: Bandwidth (3 dB) 0.63 MHz (short pulse); 0.22 MHz (long pulse) Phase control Selectable Receiver channels Linear output I/Q; log output Dynamic range 95 dB max; 93 dB at 1 dB compression Minimum detectable signal -113 dBm Noise temperature 450 K Intermediate frequency 57.6 MHz Sampling rate 600 kHz https://www.nap.edu/read/10394/chapter/11#70
milstar: http://www.qsl.net/n9zia/pdf/wsr-88d.pdf
milstar: http://www.ee.fju.edu.tw/pages/032_faculty/sclin/lecture/Rada_System_Design/Chapter7.pdf 7 - 28 Chapter 7: Radar Receiver Dr. Sheng-Chou Lin Radar System Design Pulse Compression • Allow a radar to use a long pulse to achieve high radiated energy and simultaneously to obtain range resolution • Use freq. or phase modulation to wider the signal bandwidth • Linear FM pulse compression • A stable but noncoherent LO • RF and IF processing circuitry must be broadband • IF amplifier must have sufficient bandwidth and linear phase over the band • Compressive filters used are surface acoustic wave (SAW) devices. analog device is used to obtained a compressed video output. 7 - 29 Chapter 7: Radar Receiver Dr. Sheng-Chou Lin Radar System Design Frequency Stepped Coherent Receiver High-range resolution • Wideband frequency stepped waveform • processing the received echo using FFT • Coherent or noncoherent detection • Coherent processing can increase the receiver SNR • STALO with a frequency synthesizer whose output frequency is selectable in N discrete steps of step size • Total bandwidth = • Wide bandwidth requirement for the receiver front end (circulator, protector, RF mixer • effectively generates a wideband signal while maintaining a narrowband receive
milstar: российский скоростной ацп конвейерного типа Resolution 14 Bit Sample rate 125 MSPS; Parallel CMOS and LVDS output; Single power supply 1.8V; SNR - 69.9dBFS; INL - 3.0 LSB; 180 nm CMOS process. http://www.milandr.com/ICDCS.php#/ https://www.milandr.ru/upload/smi/konveyernyy_atsp.pdf В статье представлен первый конвейерный аналого-цифровой преобра- зователь (АЦП) 5101н В025 в разрабатываемой линейке АЦП компании «миландр». Первый быстродействующий 14 - разряд - ный АЦП в линейке преобразователей ком - пании «Миландр» К5101НВ025, выполнен- ный по технологии 0,18 мкм, достигает со- отношения сигнал/шум 64 дБ и диапазона, свободного от гармоник, 75 дБ при частоте выборки 75 Мвыб./c.
milstar: Динамический диапазон радара AN/FPQ программы Аполлон более 120 дб Антенна 8.8 метра диаметром C band 5.4-5.9 Ghz 4.8 квт средней мощности,3 мегаватта импульсной мощности промежуточная частота-30 мегагерц, полоса сигнала -1.6 мегагерц Дальность более 60 000 километров при разрешении +- 2 метра http://en.wikipedia.org/wiki/AN/FPQ-6 http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19680003409_1968003409.pdf ########## 37 metr Dish Lincoln laboratory radar The three radar intermediate-frequency inputs to the A/D board are 20 MHz bandwidth centered at 10 MHz, and are thus sampled with a 40 MHz clock http://www.ll.mit.edu/publications/journal/pdf/vol21_no1/21_1_7_Eshbaugh.pdf FIGURE 16. Single-channel radar channel processing performed by DPCS for a typical stretch waveform. --- The SPS-48E radar (Fig. 1) uses a triple conversion receiver. The system is wideband until the second intermediate frequency (IF) conversion, where the individual beams are bandpass filtered and separated. Since three beams are used in the DMTI, there are three coherent oscillator frequencies (one for each beam) in the final conversion of the receiver (final IF is about 1.5 MHz). A single analog-to-digital (A/D) converter is used for each beam. In-phase and quadrature (I/Q) data are developed based on samples that are spaced at multiples of 90° at the IF frequency. The interpolation filter develops the I/Q estimates from A/D samples http://techdigest.jhuapl.edu/TD/td1803/roul.pdf The AN/SPS-48G is a long-range, three-dimensional (3D), air search radar that is progressively being installed on CVN, LHA, LHD and LPD classes of ships, replacing the AN/SPS-48E. The program of record is to backfit the existing AN/SPS-48E population with the AN/SPS-48G variant from 2011 through 2021, and to keep this system operational through the year 2050. As of the end of 2016, the AN/SPS-48G is already installed or in the process of installation aboard CVNs 68-72, CVNs 74-76, LHDs 1-3, LHD 7, LHA 7 and LPDs 26-27. The AN/SPS-48G is used to provide full volumetric detection data for the Ship Self Defense System (SSDS) via the Cooperative Engagement Capability (CEC) or the SYS-2 tracker; Air Intercept Control; Anti-Ship Cruise Missile detection including low elevation and high diver targets; backup aircraft marshalling; and the new Hazardous Weather Detection and Display Capability. http://www.navy.mil/navydata/fact_display.asp?cid=2100&tid=1250&ct=2
milstar: http://www.wirelessinnovation.org/assets/Proceedings/2012Europe/2012-europe-a-4.1.3-ulbricht-presentation.pdf Analog-to-Digital Conversion – the Bottleneck
milstar: http://www.rfcafe.com/references/electrical/ew-radar-handbook/receiver-sensitivity-noise.htm
milstar: https://www.aticourses.com/sampler/Modern_Missile_Analysis.pdf
milstar: http://helitavia.com/skolnik/Skolnik_chapter_19.pdf Pulse Doppler (PD) Operation. 2 " 6 Semiactive systems using other than CW illumination have been employed. Some early systems employed noncoherent pulse waveforms, but they are not suitable for operation in clutter (except for very large target cross sections). Coherent ---- Active seekers, since they use a single antenna both to transmit and to re- ceive, cannot use CW because of the very limited isolation achievable. Noncoherent pulse or coherent PD waveforms have been employed, and either the central-line processing or the range-gated approach can be used for coherent operation
milstar: http://eadcgroup.com/data/documents/RadarSimplified_copy.pdf https://www.d-ta.com/company/
milstar: Imaging radars such as the Haystack Auxiliary radar (HAX), HUSIR, and the Millimeter-Wave radar (MMW) on Kwajalein Atoll, Marshall Islands, employ a linear frequency-modulated (LFM) waveform and stretch pro - cessing to allow low-rate sampling of the demodulated signal [1]. The stretch method mixes the received signal with a delayed copy of the transmitted signal, called the deramp waveform, to effectively perform a range-to-fre - quency conversion over a small swath (in time and dis - tance) containing the target. For example, HUSIR sweeps from 92 GHz to 100 GHz in pulse widths varying from 51.2 μ s to 819.2 μ s, providing a range swath of 7 m to 120 m, depending on waveform. https://www.ll.mit.edu//publications/journal/pdf/vol21_no1/21_1_7_Eshbaugh.pdf
milstar: Before discussing the STAP algorithm, it may help to provide some context. STAP is basically an adaptive filter, which can filter over the spatial and temporal (or time) domain. The goal of STAP is to take a hypothesis that there is a target at a given location and velocity, and create a filter that has high gain for that specific location and velocity, and apply proportional antenuation of all signals (clutter, jammers and any other unwanted returns). https://www.eetimes.com/document.asp?doc_id=1278878 In fact, this is a very conservative scenario. The PRF is rather low and the number of antenna array inputs is very small. Should the number of antenna array inputs increase by 12 to 48, the processing load of the matrix processing, in particular QR Decomposition, goes up by the third power or 64 times. This would require over 3 TeraFLOPs of realtime floating point processing power. Because of this, the limitations on STAP are clearly the processing capabilities of the radar system.
milstar: http://iaiest.com/dl/journals/8-%20IAJ%20of%20Innovative%20Research/v2-i9-sep2015/paper1.pdf
milstar: http://www.microwavejournal.com/articles/2046-integrated-radar-receiver-front-ends
milstar: http://www.microwavejournal.com/articles/2018-advances-in-receiver-front-end-and-processing-components
milstar: https://www.researchgate.net/publication/261267768_A_high-dynamic_range_SiGe_low-noise_amplifier_for_X-band_radar_applications
milstar: http://www.rfcafe.com/references/articles/wj-tech-notes/Rec_dyn_range1.pdf
milstar: http://www.r-390a.net/Receiver-Specifications-Explaned.pdf
milstar: . The S-Band Transponder had to be limited in size and weighed only eight pounds. Another major challenge occurred when determining how to get signals across millions—let alone billions—of miles without consuming massive amounts of power. The radio frequency subsystem can pick up a signal from Earth that is infinitesimal—just .0000000000000000001 of a watt. 10^-19 watt = -190 dbw = -160dbm https://gdmissionsystems.com/Articles/2017/08/31/news-voyager-exploring-the-unknown-for-40-years For 50 Ω System -190 dbw = -160dbm -107 dbm = 1 microvolt -127 dbm =0.1 microvolt -147 dbm = 0.01 microvolt -160 dbm = 0.00224 microvolt -167 dbm = 0.001 microvolt -174 dbm = 0.000447 microvolt/hz -galaktical noise
milstar: https://gdmissionsystems.com/products/satcom-technologies/satcom-electronics-products/low-noise-amplifiers/x-band-low-noise-amplifier https://gdmissionsystems.com/products/satcom-technologies/satcom-electronics-products/low-noise-amplifiers/ka-band-low-noise-amplifier https://gdmissionsystems.com/products/satcom-technologies/satcom-electronics-products/low-noise-amplifiers/c-band-low-noise-amplifier https://gdmissionsystems.com/products/satcom-technologies/satcom-electronics-products/low-noise-amplifiers/ka-band-low-noise-amplifier
milstar: https://www.phys.hawaii.edu/~anita/new/papers/militaryHandbook/rcvr_sen.pdf
milstar: Typical values for maximum sensitivity of receivers would be: RWR -65 dBm Pulse Radar -94 dBm CW Missile Seeker -138 dBm
milstar: High-Dynamic-Range Receivers for Digital Beam Forming Radar Systems https://ieeexplore.ieee.org/document/4250284 In principle, a DBF system with N receivers should attain a signal-to-noise ratio (SNR) improvement of N over that of a single receiver system, assuming the noise is decorrelated in all the receiver channels. However, the total single and two-tone, spur-free dynamic range (SFDR) may not achieve the N-fold improvement if errors and distortion in the system are correlated. ################# The receiver had two down-conversion stages from the S-Band range input (2.7 GHz to 3.7 GHz) to 75 MHz for operation in the second Nyquist zone using a 14-bit ADC sampled at 100MHz. The instantaneous receiver bandwidth was about 15 MHz, set by an anti-aliasing filter placed at the ADC input. A survey of five mixer candidates was conducted by measuring their spur levels. Lowest (−127dBc)5×4 spurs were obtained for mixer SM5TH by M/A-COM. The ADC increases the system noise figure by design, depending on the gain configuration. The ADC affects the output SNR significantly. The maximum output signal is limited by the ADC saturation, which is well below the saturation (OTOI −10 dB) of the analog portion of the receiver.
milstar: ermination Insensitive FET MixerThe receiver also employs a MITEQ high IP3 termi-nation insensitive mixer (TIM). The high intercept pointis provided by a dual FET architecture that is surround-ed by 90 degree hybrid couplers. The coupler terminationshelp reduce the sensitivity of the mixer response to exter-nal termination impedances, improve input compressionof the mixer, and provide cancellation of the even-orderintermodulation products. The mixer has an input thirdorder intercept performance of +33 dBm and a conversionloss of 9 dB. https://www.highfrequencyelectronics.com/May08/HFE0508_Cannata.pdf
milstar: http://www.ee.fju.edu.tw/pages/032_faculty/sclin/lecture/Rada_System_Design/Chapter7.pdf
milstar: A NEW UHF HIGH DYNAMIC RANGE RECEIVERFOR THE ARECIBO OBSERVATORY https://etda.libraries.psu.edu/files/final_submissions/8369 In this paper, a new design of a low noise amplifier (LNA) is presented, which will extend the receiver’s sensitivity and exhibit a faster recovery time from interference caused by the radar’s transmitter pulse. In addition, a compact high temperature superconducting (HTS) bandpass filter is introduced to the receiver chain to replace the receiver’s current cavity resonator filter. This newly designed planar filter improves the rejection of undesired signals detected bythe 430 MHz receiver chain. In addition, the bandpass filter design utilizes distributed microstrip elements to be fabricated from an Yttrium Barium Copper Oxide (YBCO) thin film superconductor on a Magnesium Oxide (MgO) substrate. Figure 3-1: Balanced Amplifier Configuration.The configuration features a hybrid coupler that splits the input signal into two channels 90 degrees out of phase from each other. The couplers serve to terminate reflections created by each channels’ matching networks (labeled MN). Identical amplifiers (Amp A and B) boost the signal power. Finally, an additional coupler combines the signals and produces a single in-phase output.
milstar: https://www.almaobservatory.org/en/about-alma-at-first-glance/how-alma-works/technologies/receivers/ if processing 8 2-4 ghz bands
milstar: https://science.nrao.edu/science/meetings/2018/16th-synthesis-imaging-workshop/talks/McKinnon_Antennas.pdf
milstar: file:///root/Downloads/ALMAdevel2019_Huang.pdf n-house designed MMIC active mixer is replaced by commercial passive double-balanced MMIC mixer (model number: MM1-2567LS) by MarkiMicrowave. The conversion loss of the Markimixer is 7 to 9 dB.
milstar: https://www.researchgate.net/publication/311430571_The_Atacama_Large_Millimetersubmillimeter_Array_ALMA_Band-1_Receiver
milstar: http://www.rfcafe.com/references/articles/wj-tech-notes/high-dynamic-range-receiver-parameters-v7-2.pdf
milstar: https://www.highfrequencyelectronics.com/May08/HFE0508_Cannata.pdf
milstar: https://safe.nrao.edu/wiki/pub/NGVLA/NgVLAWorkshop/Murden_Analog_Device_Ultra_Wideband_.pdf
milstar: https://library.nrao.edu/public/pubs/obsstat/VLAOS_0792.pdf
milstar: https://my.fit.edu/~tcrandel/ece5115/receiver_design_tutorial.pdf Receiver Design– TutorialJames B. Offner (Author)Harris Corporation Government Communications Systems Division 2400 Palm Bay RdPalm Bay, Florida 32905 Abstract––Numerous interrelated trade-offs are undertaken for any receiver or receive chain design, which must be jointly optimized for the intended operational environment. Some of the requirements resulting from this environment are: noise figure (NF), input 3rd order intercept point (IP3), input 1dB compression point (P1dB), dynamic range, input desensitization level, non-damage input power, out-of-band (OOB) interference rejection, gain and output power. This paper focuses on these requirements and the subtleties associated with achieving them.
milstar: 1. Географические климатические условия Гибель Испанской армады потеря флота Хубилая при попытке высадки в Японию «Божественный ветер» будет бушевать двое суток, сметая всё на своём пути Жесткие требования мореходности ( 9000 т для консервативного проекта, нe с малой площади ватерлинии жесткие требования выбора диапазонов РЛС L 750-1250 mhz и X 7600-8400 mhz 2. РЛС диапазона L лучше в условиях плохой погоды для обнаружения малозаметных низколетящих крылатых ракет требует меньше компонентов для апертуры с полным заполнением, легче удовлетворить требования пo отводу тепла и компоненты более дешевы недостаток большая площадь апертуры,однако этот диапазон используется на фрегатах водоизмещением 4100 тонн AN/SPS-49 7.3 m × 4.3 m https://en.wikipedia.org/wiki/AN/SPS-49 в самолете СУ-57 ( площадь апертуры еще меньше ) 3. для сдвоенной апертуры (как в ФРЕГАТ-М2 ) Источник: http://bastion-karpenko.ru/fregat-m2em-rls/ ВТС «БАСТИОН» A.V.Karpenko с размерами 7.3 m × 4.3 m для АФАР с полным заполнением 1000 mhz h/2 =150 mm потребуется 2*49*30 э=2940 элементов 4. концепция повсеместного(ubiquitous ) радара Naval Research Laboratory https://apps.dtic.mil/dtic/tr/fulltext/u2/a403877.pdf имеет ряд преимуществ пo сравнению с классической АФАР 5. в случае использования супергетеродина с 2 преобразованиями частоты 490 mhz ,70 mhz как в Радаре Cobra Dane https://fas.org/spp/military/program/track/cobra_dane.htm может быть реализована на "отечественных" аналого-цифровых преобразователях https://mri-progress.ru/products/bis-i-sbis/spetsialnye-sbis/sbis-16-razryadnogo-atsp/ СБИС 16-разрядного АЦП конвейерного типа с частотой дискретизации 200 МГц изготовлена по КМОП 90-нм технологии и предназначена для аналого-цифрового преобразования диффе- ренциальных аналоговых сигналов. В микросхеме реализован алгоритм встроенной калибров- ки передаточной характеристики. Функциональный аналог ADS5485 фирмы Texas Instruments. https://mri-progress.ru/products/all-lists/K5111HB015.pdf ############################################################### 6. в случае использования AD9625 12 bit 2-2.6 GSPS SFDR 80dbc возможен отказ от супергетеродина и смесителей RF Sampling NLEQ добавит 10 db to 80 dbc https://www.analog.com/media/en/technical-documentation/tech-articles/Review-of-Wideband-RF-Receiver-Architecture-Options.pdf https://archive.ll.mit.edu/HPEC/agendas/proc09/Day2/S4_1405_Song_presentation.pdf https://dspace.mit.edu/bitstream/handle/1721.1/119717/1078637048-MIT.pdf?sequence=1&isAllowed=y ad9625 2-2.6 GSPS SFDR 80 dbc at 1000 mhz NLEQ добавит 10 db это уже приличный результат для радара с полностью цифровым формированием луча ############################################# 7. AD9625 price 642$ per 1 https://www.analog.com/en/products/ad9625.html#product-overview https://www.analog.com/media/en/technical-documentation/data-sheets/AD9625.pdf The AD9625 architecture includes two DDCs, each designed to extract a portion of the full digital spectrum captured by the ADC. Each tuner consists of an independent frequency synthesizer and quadrature mixer; a chain of low-pass filters for rate conversion follows these components. Assuming a sampling frequency of 2.500 GSPS, the frequency synthesizer (10-bit NCO) allows for 1024 discrete tuning frequencies, ranging from −1.2499 GHz to +1.2500 GHz, in steps of 2500/1024 = 2.44 MHz. The low-pass filters allow for two modes of decimation. A high bandwidth mode, 240 MHz wide (from −120 MHz to +120 MHz), sampled at 2.5 GHz/8 = 312.5 MHz for the I and Q branches separately. The 16-bit samples from the I and Q branches are transmitted through a dedicated JESD204B interface. A low bandwidth mode, 120 MHz wide (from −60 MHz to +60 MHz), sampled at 2.5 GHz/16 = 156.25 MHz for the I and Q branches separately. The 16-bit samples from the I and Q branches are transmitted through a dedicated JESD204B interface. 8. примеры различных РЛС диапазона L Su-57,Cobra Dane ,FPS-117, Gamma DE,AN/SPS-49,Protivnik ,smart-l mm http://ausairpower.net/APA-Rus-Low-Band-Radars.html#mozTocId829681 https://lockheedmartin.com/content/dam/lockheed-martin/rms/documents/ground-based-air-surveillance-radars/FPS-117-fact-sheet.pdf https://www.radartutorial.eu/19.kartei/01.oth/karte003.en.html https://www.thalesgroup.com/en/smart-l-mm
milstar: https://www.jhuapl.edu/Content/techdigest/pdf/V22-N03/22-03-Cole.pdf AM/FM Noise in the Target Illumination Signal for Semi-Active Missiles Low-frequency (approximately10 to 400 Hz) noise limits are established such that target energy spreading out of the fast Fourier transform (FFT) bin occupied by the target does not adversely affect the missile’s target coherency test. Mid-frequency (approximately ≥400 Hz to ≤5 kHz) noise should not allow clutter to mask a crossing or slow target. High-frequency (>5 kHz) noise should not permit maximum clutter or spillover from degrading target sensitivity. When specifying noise, a specification bandwidth is also required. An industry-standard term for quantifying phase noise, denoted by L(f), is defined as decibels rela-tive to the carrier per hertz of bandwidth. (The terms phase noise and FM noise are used interchangeably in this article.) The noise specifications discussed in this article are given in various bandwidths as a function of frequency offset from the carrier. At the lower fre-quencies, a bandwidth that is 10 times smaller than the mid- and high-frequency ranges is typically used. We have some specifications where the high-frequency bandwidth is 100 times larger than the low-frequency bandwidth. The use of different bandwidths for differ-ent areas of the Doppler spectrum is a trade-off between two factors: (1) the need to detect narrowband signals in white Gaussian noise, which requires narrowband fil-ters, and (2) the need to complete the measurement in a timely fashion, which requires a filter with a bandwidth that is at least 10 times wider than the low-frequency bandwith
milstar: Target Discrimination Target discrimination is a critical capability for the ASM seeker, especially in the presence of jamming and other EA (Electronic Attack). For this analysis, it is only indicated that the coherent seeker presents more information at, perhaps higher resolution, to the postprocessor for discrimination purposes https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.928.3912&rep=rep1&type=pdf
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