A signal processing view of strip-mapping synthetic aperture radar

Munson, D.C., Jr.; Visentin, R.L., "A signal processing view of strip-mapping synthetic aperture radar," Acoustics, Speech and Signal Processing, IEEE Transactions on , vol.37, no.12, pp.2131,2147, Dec 1989. doi: 10.1109/29.45556

Abstract: The authors derive the fundamental strip-mapping SAR (synthetic aperture radar) imaging equations from first principles. They show that the resolution mechanism relies on the geometry of the imaging situation rather than on the Doppler effect. Both the airborne and spaceborne cases are considered. Range processing is discussed by presenting an analysis of pulse compression and formulating a mathematical model of he radar return signal. This formulation is used to obtain the airborne SAR model. The authors study the resolution mechanism and derive the signal processing relations needed to produce a high-resolution image. They introduce spotlight-mode SAR and briefly indicate how polar-format spotlight processing can be used in strip-mapping SAR. They discuss a number of current and future research directions in SAR imaging

Reference

Wide-angle radar imaging using time-frequency distributions

Lanterman, A.D.; Munson, D.C., Jr.; Wu, Y., "Wide-angle radar imaging using time-frequency distributions," Radar, Sonar and Navigation, IEE Proceedings - , vol.150, no.4, pp.203-11,, 1 Aug. 2003. doi: 10.1049/ip-rsn:20030712

Abstract: Low-frequency radar systems provide some attractive advantages in a few niche applications, such as foliage penetration and covert operation. In low-frequency imaging systems, data must be collected over a wide range of angles to obtain cross-range resolution comparable to that obtainable from a competing small-angle high-frequency system. The reflectivity of a target varies with aspect angle; although this variation is usually ignored by traditional radar imaging algorithms, it sometimes cannot be neglected in wide-angle scenarios. To account for aspect dependence of reflectivity, time-frequency transforms have been invoked to generate a series of images corresponding to different look angles; these images may be considered individually or synthesised into a single image. A simple theoretical analysis with a point scatterer illustrates why the angular dependence needs explicit consideration. The potential of time-frequency methods is illustrated via simulations

Reference

The Macqueripe Missile Tracking Station - Project Trinidad

During the height of the Cold War, tensions were high between the USA and Russia. The threat of catastrophic Inter-Continental Ballistic Missiles was very real, and the USA’s main strategy for defense was Mutually Assured Destruction. The rationale was that if the Russians hit the US, that they’d be hit in exchange, and that essentially it would be suicidal for Russia to attack first.

Enter the need for the Ballistic Missile Early Warning System. Major major technological advancement for the time. To test the technology, the US used land that they had leased from the Trinidad and Tobago government (displacing my family, and many others, but that’s another chapter in local history). The tests were successful and the radar network became operational in the 1960s.

 

On August 8th, 1960, another first.

The first intercontinental voice message relayed via satellite was transmitted from the Missile Tracking Station at Macqueripe, Trinidad and received at Floyd Air Force base, New York. The very first. The pre-cursor technology that led to cell phones, the internet, satellite radio, GPS. It all started right here, in Trinidad.

Source

Радиолокационные истребители ВВС Красной Армии

Александр Медведь, Виктор Марковский

Развитие бомбардировочной авиации к концу 30-х годов сделало ее грозной силой, возможности которой стали превосходить способность ПВО отражать удары. Основная причина заключалась в том, что службы воздушного наблюдения не могли обеспечить своевременное обнаружение вражеских бомбардировщиков, наведение на них истребителей и корректировку огня зенитных батарей. Основными средствами обнаружения самолетов в СССР оставались оптические приборы (бинокли, визиры и дальномеры), малоэффективные ночью и в плохих метеоусловиях. В дополнение к ним использовались зенитные прожекторы, однако они обладали небольшой досягаемостью и были бесполезны в туман, дождь или снег. Попытки вести поиск самолетов с помощью тепло- и звукоуловителей дали неудовлетворительные результаты. Поэтому истребителям в ночное время рекомендовалось "вести поиск противника и бой с ним, пользуясь лунным освещением". Необходимость создания бортовых средств обеспечения ночного боя стала очевидной.

Летом 1940 г. под руководством начальника группы отделов спецслужб НИИ ВВС (подразделение, занимавшееся специальным оборудованием самолетов и аэродромов. Позднее выделилось в самостоятельный НИИ спецслужб ВВС) генерала С.А. Данилина состоялось совещание, на котором рассматривались разнообразные варианты решения проблемы. Наиболее перспективной признали аппаратуру радиообнаружения (термин "радиолокация" утвердился в документах и служебном лексиконе позднее, с лета 1943 г.). К этому времени станции-радиоулавливатели РУС-1 "Ревень" и РУС-2 "Редут" уже прошли испытания в ПВО Ленинграда во время войны с Финляндией и доказали свою боевую пригодность. Именно станция "Редут", разработанная в Ленинградском НИИ радиопромышленности, стала прототипом первой советской самолетной РЛС.

One day of traffic in Europe

Multifunction Phased-Array Radar: Time Balance Scheduler for Adaptive Weather Sensing

Ricardo Reinoso-Rondinel, Tian-You Yu, and Sebastián Torres, 2010: Multifunction Phased-Array Radar: Time Balance Scheduler for Adaptive Weather Sensing. J. Atmos. Oceanic Technol., 27, 1854–1867. doi: http://dx.doi.org/10.1175/2010JTECHA1420.1

Abstract. Phased-array radars (PARs) have the capability of instantaneously and dynamically controlling beam position on a pulse-by-pulse basis, which allows a single radar to perform multiple functions, such as tracking multiple storms or weather and aviation surveillance. Moreover, these tasks can be carried out with different update times to achieve the goal of better characterizing and forecasting the storms of interest. However, these tasks usually compete for finite radar resources, and scheduling algorithms are often needed to address resource contention. To capitalize on the PAR capabilities, an algorithm based on the concept of time balance (TB) is developed for adaptive weather sensing. Two quality measures are introduced to quantify the gain of adaptive sensing relative to standard scanning patterns used by the Weather Surveillance Radar-1988 Doppler (WSR-88D). A simulation experiment is performed to demonstrate the advantages of adaptive sensing and to test and verify the performance of the TB scheduling algorithm. It is shown that the gain of adaptive sensing can be realized by the TB scheduler; that is, storms of interest can be revisited more frequently within a relatively short period time compared to conventional scanning.