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公开(公告)号：US5142291A
公开(公告)日：1992-08-25
申请号：US563129
申请日：1990-08-03
IPC分类号： G01K11/00
CPC分类号： G01K11/006
摘要： A technique for near-field tomographic imaging using a multiple-receiver correlating interferometer. A target object or scene to be imaged is located in a near-field or Fresnel region of a receiver system. The target object radiates or reflects a signal that is sensed by a plurality of antennas. The received signals are correlated using conventional correlation algorithms. An image pixel for a focal point is then computed by correcting a differential time delay between a signal emitted at the focal point and received at first and second antennas. The system is focused on the target object by correcting a phase term of the correlation algorithms. The phase term is corrected by multiplying the correlation algorithms by a phase factor. A peak correlated value is developed when the focal point is at the target object location. A series of snapshots is generated from data produced by the focussing process, as the focal point is moved through the scene. The snapshots are successively superimposed, using tomographic techniques, to form a high resolution image map. The system achieves extremely high resolutions, rivalling those of synthetic aperture radar.
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公开(公告)号：US4783640A
公开(公告)日：1988-11-08
申请号：US138541
申请日：1987-12-28
IPC分类号： G01R29/00 , G01R23/163 , G01R23/175 , H01P5/16 , H01P9/00 , H01P5/12
CPC分类号： H01P5/16 , G01R23/163 , G01R23/175
摘要： A correlator apparatus that simultaneously delays two time-varying input signals using just a single transmission line, with the signals being connected to opposite ends of the line. Directional couplers spaced along the transmission line extract delayed versions of the two input signals, for correlation by a bank of correlators, to produce a correlation envelope for the two signals. The apparatus is substantially less massive than prior apparatus of this kind and can be easily constructed and aligned.
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3.发明授权Radiometer system incorporating a cylindrical parabolic reflector and minimum redundancy array feed 失效辐射计系统包含圆柱形抛物面反射器和最小冗余阵列进给
公开(公告)号：US5072226A
公开(公告)日：1991-12-10
申请号：US534217
申请日：1990-06-07
CPC分类号： H01Q19/175 , G01K11/006 , G01S13/89 , G01S3/04
摘要： A radiometer system is disclosed, the system incorporating a cylindrical parabolic reflector and a plurality of radiation sensors disposed along the focal line of the reflector in a minimum redundancy array. Digital processing circuitry is connected to the output of the sensors for digitally processing signals using a cross-correlation signal processing and fast Fourier transform circuitry to generate image signals, the system providing reduced weight and increased signal integration time. Several embodiments of the system are disclosed including analog and digital versions having a multiplicity of antenna configurations.
摘要翻译： 公开了一种辐射计系统，该系统包括圆柱形抛物面反射器和沿着反射器的焦线以最小冗余阵列设置的多个辐射传感器。 数字处理电路连接到传感器的输出端，用于使用互相关信号处理和快速傅里叶变换电路数字处理信号，以产生图像信号，该系统提供减小的重量和增加的信号积分时间。 公开了该系统的几个实施例，其包括具有多个天线配置的模拟和数字版本。
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公开(公告)号：US4994809A
公开(公告)日：1991-02-19
申请号：US490032
申请日：1990-03-07
CPC分类号： G01S13/003
摘要： The polystatic correlating radar includes a plurality of radar receivers which receive a signal reflected from an object from one or more radar signal transmitters. Signals received from the plurality of receivers are cross correlated to provide high resolution of the angular location, range, and radial velocity measurements, as well as tangential velocity measurements for close targets.
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5.发明授权Detector power linearity requirements and verification techniques for TMI direct detection receivers 失效TMI直接检测接收机的检测器功率线性要求和验证技术
公开(公告)号：US5644243A
公开(公告)日：1997-07-01
申请号：US349348
申请日：1994-12-05
CPC分类号： G01R21/10 , G01K11/006 , G01R35/00
摘要： A system (36, 98) for determining the linearity of an RF detector (46, 106). A first technique involves combining two RF signals from two stable local oscillators (38, 40) to form a modulated RF signal having a beat frequency, and applying the modulated RF signal to a detector (46) being tested. The output of the detector (46) is applied to a low frequency spectrum analyzer (48) such that a relationship between the power levels of the first and second harmonics generated by the detector (46) of the beat frequency of the modulated RF signal are measured by the spectrum analyzer (48) to determine the linearity of the detector (46). In a second technique, an RF signal from a local oscillator (100) is applied to a detector (106) being tested through a first attenuator (102) and a second attenuator (104). The output voltage of the detector (106) is measured when the first attenuator (102) is set to a particular attenuation value and the second attenuator (104) is switched between first and second attenuation values. Further, the output voltage of the detector (106) is measured when the first attenuator (102) is set to another attenuation value, and the second attenuator (104) is again switched between the first and second attenuation values. A relationship between the voltage outputs determines the linearity of the detector (106).
摘要翻译： 一种用于确定RF检测器（46,106）的线性度的系统（36,98）。 第一技术涉及组合来自两个稳定的本地振荡器（38,40）的两个RF信号以形成具有拍频的调制RF信号，并将经调制的RF信号施加到被测试的检测器（46）。 检测器（46）的输出被施加到低频频谱分析器（48），使得由检测器（46）产生的调制RF信号的拍频的第一和第二谐波的功率电平之间的关系是 由频谱分析仪（48）测量以确定检测器（46）的线性度。 在第二技术中，来自本地振荡器（100）的RF信号被施加到通过第一衰减器（102）和第二衰减器（104）测试的检测器（106）。 当第一衰减器（102）被设置为特定的衰减值并且第二衰减器（104）在第一和第二衰减值之间被切换时，测量检测器（106）的输出电压。 此外，当第一衰减器（102）被设置为另一衰减值时，测量检测器（106）的输出电压，并且第二衰减器（104）再次在第一和第二衰减值之间切换。 电压输出之间的关系决定了检测器（106）的线性。
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