-
公开(公告)号：US4846571A
公开(公告)日：1989-07-11
申请号：US929572
申请日：1986-11-03
CPC分类号： G01S17/325 , G01S7/4917 , G01S7/499 , G01S7/4814
摘要： A laser is provided for generating a beam of continuous wave (CW) electromagnetic energy having a nominal frequency and amplitude. The frequency of the CW beam is modulated (FM) from the nominal frequency. The amplitude of the frequency modulated beam is modulated (AM) from the nominal amplitude to produce an amplitude and frequency modulated continuous wave (AM-FM CW) beam of energy. A local oscillator beam is produced from the frequency modulated CW beam. The AM-FM CW beam is directed for reflection by a target. The target-reflected return portions of the AM-FM CW beam are combined with the frequency modulated local oscillator beam to produce a beat frequency signal which is subsequently detected, the beat frequency signal having a frequency component representative of the range of the target. Such arrangement, when implemented in a radar system, provides such radar system with accurate target range measurements unambiguous over large ranges. Further, such AM-FM CW signal provides high resolution between target-reflected return signals of such AM-FM CW signal and returns from near-field atmospheric clutter.
摘要翻译： 提供激光器用于产生具有标称频率和幅度的连续波（CW）电磁能量束。 CW波束的频率从标称频率调制（FM）。 频率调制波束的幅度从标称幅度调制（AM），以产生幅度和频率调制的连续波（AM-FM CW）能量束。 从调频CW波束产生本地振荡器波束。 AM-FM CW光束被指向用于目标的反射。 将AM-FM CW波束的目标反射返回部分与调频本地振荡器波束组合以产生随后检测到的拍频信号，拍频信号具有代表目标范围的频率分量。 这种布置在雷达系统中实现时，可以在大范围内为这种雷达系统提供准确的目标范围测量。 此外，这种AM-FM CW信号在这样的AM-FM CW信号的目标反射返回信号和从近场大气杂波返回之间提供高分辨率。
-
公开(公告)号：US4812035A
公开(公告)日：1989-03-14
申请号：US929686
申请日：1986-11-03
CPC分类号： G01S17/36 , G01S17/325 , G01S7/4917 , H01S3/139
摘要： A laser radar system wherein a beam of continuous wave (CW) electromagnetic energy is generated with frequency modulation (FM) and amplitude modulation (AM) being imposed thereon to produce an amplitude and frequency modulated, continuous wave beam of energy. The AM-FM CW beam is transmitted toward a selected target, portions of the transmitted beam being reflected by the target and received along with portions of the transmitted beam reflected by unselected targets and atmospheric clutter. A first signal is produced in response to the frequency modulation on the received beam portions reflected by the selected target, such first signal representing the approximate range of the selected target and substantially resolving the selected target from unselected targets and atmospheric clutter and having a relatively long ambiguous range interval. A second signal is produced in response to the amplitude modulation on the received beam portions reflected by the selected target, the second signal representing the accurate range of the selected target within a relatively short ambiguous range interval. The second signal provides poor resolution between the selected target and the unselected targets and atmospheric clutter. The first and second signals are combined to produce an output signal having the relatively high resolution and long ambiguous range interval of the first signal and providing the accurate selected target range measurement of the second signal.
摘要翻译： 一种激光雷达系统，其中通过频率调制（FM）和幅度调制（AM）产生连续波（CW）电磁能量束，以产生幅度和频率调制的连续波束。 AM-FM CW波束朝向所选择的目标发送，所发送的波束的部分被目标物反射并且被未被选择的目标物和大气杂波反射的部分发射光束一起接收。 响应于由所选择的目标反射的接收波束部分上的频率调制产生第一信号，该第一信号表示所选择的目标的近似范围，并且从未选择的目标和大气杂波基本上解决所选择的目标并且具有相对长的 模糊范围间隔。 响应于由所选择的目标反射的接收波束部分上的幅度调制产生第二信号，第二信号表示在相对较短的不明确的范围间隔内所选择的目标的精确范围。 第二个信号在所选择的目标和未选择的目标和大气杂波之间提供差的分辨率。 第一和第二信号被组合以产生具有第一信号的相对高分辨率和长的不明确的范围间隔的输出信号，并且提供第二信号的精确选择的目标范围测量。
-
公开(公告)号：US3950100A
公开(公告)日：1976-04-13
申请号：US518924
申请日：1974-10-29
申请人： Wayne H. Keene , Clarke E. Harris , Albert V. Jelalian , Christopher R. Miller , Richard E. Seavey
发明人： Wayne H. Keene , Clarke E. Harris , Albert V. Jelalian , Christopher R. Miller , Richard E. Seavey
CPC分类号： H01S3/1304 , G01P3/366 , G01P5/26 , G01S17/58 , G02F2/002
摘要： A laser heterodyne system is disclosed wherein received reflections of a beam of coherent light are amplified in a laser. The amplified received reflections are heterodyned with the light produced by the laser and the resulting beat frequency is detected using a photodetector. A controller, responsive to the beat frequency, controls, in one case, the frequency of a transmitting laser, and hence the frequency of the received light, and, in another case, the frequency of the light produced by the amplifying laser so that, in either case, the difference between the frequency of the received light and the frequency of the light produced by the amplifying laser is adjusted to maximize the amplification of the received light by the amlifying laser prior to detection by the photodetector.
-
公开(公告)号：US4902125A
公开(公告)日：1990-02-20
申请号：US213816
申请日：1988-06-30
CPC分类号： H01S3/2308 , G01S17/32 , G01S7/481 , G01S7/499 , H01S3/139 , H01S3/2316
摘要： A laser radar system having amplification of the optical beam. In a system where it is desired to achieve greater information content or greater system sensitivity, one or more laser amplifiers in the beam paths provide greater optical power for increased distance. Eleven system architectures are disclosed for use with a modified Mach-Zehnder interferometer, eleven are disclosed for use with a Fizeau interferometer, and three are disclosed for use in a noncoherent optical system. The embodiments are distinguished by the number and placement of the laser amplifiers in the optical paths of the system.
-
公开(公告)号：US3984686A
公开(公告)日：1976-10-05
申请号：US637247
申请日：1975-12-03
申请人： James C. Administrator of the National Aeronautics and Space Administration, with respect to an invention of Fletcher , James W. Bilbro , Werner K. Dahm , Ronald B. Campbell, Jr. , Robert M. Huffaker , Harold B. Jeffreys , Albert V. Jelalian , Wayne H. Keene , Michael C. Krause , Thomas R. Lawrence , Charles M. Sonnenschein , David J. Wilson , James A. L. Thomson
发明人： James C. Administrator of the National Aeronautics and Space Administration, with respect to an invention of Fletcher , James W. Bilbro , Werner K. Dahm , Ronald B. Campbell, Jr. , Robert M. Huffaker , Harold B. Jeffreys , Albert V. Jelalian , Wayne H. Keene , Michael C. Krause , Thomas R. Lawrence , Charles M. Sonnenschein , David J. Wilson , James A. L. Thomson
摘要： A system for remotely measuring velocities present in discrete volumes of air in which a CO.sub.2 laser beam is focused by a telescope at such a volume, a focal volume, and within the focusable range, near field, of the telescope. The back scatter, or reflected light, principally from the focal volume, passes back through the telescope and is frequency compared with the original frequency of the laser, and the difference frequency or frequencies represent particle velocities in that focal volume.
摘要翻译： 远程测量存在于离散体积的空气中的速度的系统，其中CO 2激光束由望远镜在望远镜的这种体积，焦点体积和可聚焦范围的近场内聚焦。 主要来自焦点体积的背散射或反射光通过望远镜返回，并且与激光器的原始频率相比频率，而差频率或频率表示该焦点体积中的粒子速度。
-
公开(公告)号：US5438449A
公开(公告)日：1995-08-01
申请号：US125519
申请日：1987-11-25
CPC分类号： G01C21/00 , G01S7/4814 , G01S7/4817 , G02B26/08 , G02B5/122
摘要： An optical beam switch is disclosed for sequentially pointing a laser beam to a plurality of terrestrial target locations at predetermined depression angles and at angular positions relative to a reference direction. The switch includes a CW laser whose collimated output beam is directed into a rotating retroreflector. The moving beam reflected therefrom describes a continuous circular path across the upper surface of a beam deflection device. The beam deflection device comprises a plurality of beam refracting prisms. The index of refraction and angulation of each prism determines the depression angle and azimuthal angle of the deflected beam. The depression angle is held precisely constant as the incident beam describes its arcuate path across the upper surface of the prism. The retroreflector may comprise three mutually-perpendicular mirrors, joined at a vertex, for providing a reflected beam parallel to and displaced from the incident beam. Alternatively, the retroreflector may comprise a triple mirror prism.
摘要翻译： 公开了一种光束开关，用于将激光束以预定的下倾角和相对于参考方向的角位置顺序地指向多个地面目标位置。 该开关包括一个CW激光器，其准直的输出光束被引导到旋转后向反射器中。 从其反射的移动光束描述了横过光束偏转装置的上表面的连续圆形路径。 光束偏转装置包括多个光束折射棱镜。 每个棱镜的折射率和角度决定了偏转光束的俯角和方位角。 当入射光束描述穿过棱镜上表面的弧形路径时，凹陷角保持精确恒定。 后向反射器可以包括在顶点处连接的三个相互垂直的反射镜，用于提供平行于入射光束并从入射光束移位的反射光束。 或者，后向反射器可以包括三镜棱镜。
-
公开(公告)号：US4721385A
公开(公告)日：1988-01-26
申请号：US940156
申请日：1986-12-09
申请人： Albert V. Jelalian , Wayne H. Keene , Charles M. Sonnenschein , Clarke E. Harris , Clifford E. Morrow
发明人： Albert V. Jelalian , Wayne H. Keene , Charles M. Sonnenschein , Clarke E. Harris , Clifford E. Morrow
CPC分类号： G01S17/42 , G01S17/325 , G01S17/50
摘要： A scanning laser radar system utilizing a frequency modulated (fm)-continuous wave (cw) beam to coherently detect echo signal returns from an object in a predetermined region. The frequency of the beam is repeatedly changed as a function of time to produce a symmetrical triangular-shaped frequency modulated waveform. The echo signals received are frequency shifted, as a function of range and Doppler shift, from the signal being transmitted at that time. The frequency shift is detected by homodyning a portion of the instantaneous transmitted signal with the received echo signal to produce an output signal having a frequency which is substantially constant during a portion of the frequency modulation period. The constant frequency portion of the output signal is related to the range and Doppler speed of the target. Target information such as range, Doppler speed, intensity and angle information are derived by processing the output signal. The signal to noise ratio of the output signal is improved by using a frequency modulation period greater than the scanning time across an arc of a size equal to a predetermined multiple of the beamwidth because with such relationship the time duration of the constant amplitude portion of the output signal is increased. Further, with such arrangement, because of the relatively long modulation period, the ambiguity in detection of the range to the target is reduced. The system is particularly useful in terrain following or obstacle avoidance applications.
摘要翻译： 利用频率调制（fm） - 连续波（cw）波束的扫描激光雷达系统相干地检测来自预定区域中的物体的回波信号返回。 光束的频率作为时间的函数重复改变以产生对称的三角形调频波形。 接收到的回波信号作为距离和多普勒频移的函数从当时发送的信号进行频移。 通过用接收到的回波信号对瞬时发送信号的一部分进行差分来检测频移，以产生在频率调制周期的一部分期间具有基本恒定的频率的输出信号。 输出信号的恒定频率部分与目标的范围和多普勒速度有关。 通过处理输出信号来导出诸如范围，多普勒速度，强度和角度信息的目标信息。 通过使用大于等于波束宽度的预定倍数的大小的弧的扫描时间的频率调制周期来改善输出信号的信噪比，因为这样的关系是恒定振幅部分的持续时间 输出信号增加。 此外，通过这样的配置，由于相对长的调制周期，检测到目标的范围的模糊性降低。 该系统在地形跟踪或避障应用中特别有用。
-
公开(公告)号：US4326799A
公开(公告)日：1982-04-27
申请号：US602349
申请日：1975-08-06
申请人： Wayne H. Keene , Albert V. Jelalian
发明人： Wayne H. Keene , Albert V. Jelalian
CPC分类号： G01S17/42 , G01B11/26 , G01C11/025 , G02B26/10
摘要： A scanning system combining active and passive detection of radiation from targets. In the active mode, a laser beam is scanned with a rotating wedge in a downward looking Palmer pattern, a portion of the beam is reflected from targets, and coherent detection is performed on the returned signals. Means is disclosed for automatically compensating for misalignment between the signal return beam and local reference beam upon the coherent detector. In the passive mode, infrared radiation inherently emitted by targets is also detected.
摘要翻译： 一种扫描系统，主动和被动地检测来自目标的辐射。 在激活模式下，用向下看的Palmer模式的旋转楔形物扫描激光束，一部分光束从目标物体反射，并对所返回的信号进行相干检测。 公开了用于在相干检测器上自动补偿信号返回光束和局部参考光束之间的未对准的装置。 在被动模式下，也检测到目标本身发射的红外辐射。
-
公开(公告)号：US4167329A
公开(公告)日：1979-09-11
申请号：US859904
申请日：1977-12-12
摘要： An optically focussed laser radar operating with a radiation wavelength of typically ten microns is focussed on an object to be observed. Doppler data is obtained with a continuous wave signal by mixing a reference of the transmitted signal with a signal reflected from airborne scattering centers. The system is particularly useful for clear air turbulence applications wherein aerosols such as dust and pollen serve as the scattering centers for reflecting the radiation. The radar converts to a pulse Doppler system when the depth of field exceeds the desired range resolution.
摘要翻译： 以通常为10微米的辐射波长工作的光聚焦激光雷达集中在要观察的物体上。 通过将发射信号的参考与从空中散射中心反射的信号混合，通过连续波信号获得多普勒数据。 该系统对于清洁空气湍流应用特别有用，其中气溶胶如灰尘和花粉用作反射辐射的散射中心。 当景深超过所需范围分辨率时，雷达转换为脉冲多普勒系统。
-
-
-
-
-
-
-
-
搜索结果
9 条记录 (耗时 0.024 秒)
