A subsurface imaging technique using distributed sensors is introduced. Instead of monostatic transceivers employed in conventional ground penetrating radars, the proposed technique utilizes bi-static transceivers to sample the reflected signals from the ground at different positions and create a large two-dimensional aperture for high resolution subsurface imaging. The coherent processing of the samples in the proposed imaging method eliminates the need for large antenna arrays for obtaining high lateral resolution images. In addition, it eliminates the need for sampling on a grid which is a time-consuming task in imaging using ground penetration radar. Imaging results show that the method can provide high-resolution images of the buried targets using only samples of the reflected signals on a circle with the center at the transmitter location.

A subsurface imaging technique using distributed sensors is introduced. Instead of monostatic transceivers employed in conventional ground penetrating radars, the proposed technique utilizes bi-static transceivers to sample the reflected signals from the ground at different positions and create a large two-dimensional aperture for high resolution subsurface imaging. The coherent processing of the samples in the proposed imaging method eliminates the need for large antenna arrays for obtaining high lateral resolution images. In addition, it eliminates the need for sampling on a grid which is a time-consuming task in imaging using ground penetration radar. Imaging results show that the method can provide high-resolution images of the buried targets using only samples of the reflected signals on a circle with the center at the transmitter location.

A shared radar and communications system. The system includes a transmitter and a receiver. The transmitter modules signals based on a first spreading code defined at least in part by a first plurality of information bits. The first plurality of information bits encodes selected information. The transmitter transmits the modulated signals. The receiver receives a first signal and a second signal. The first signal includes the transmitted signals transmitted by the transmitter and reflected from objects in an environment. The receiver processes the first signal to detect objects in the environment. The second signal is transmitted from another system. The second signal carries a second plurality of information bits. The receiver processes the second signal to determine the second plurality of information bits. The second plurality of information bits are encoded with information selected by the other system.

In a distance detection method, a target apparatus receives a first transmit signal from a detection apparatus. The target apparatus generates a first echo signal by modulating some of reflected signals of the first transmit signal to cause a first Doppler shift between the first echo signal and the first transmit signal. The target apparatus emits the first echo signal to the detection apparatus, which derives its distance from the target apparatus based on the first echo signal.

In a distance detection method, a target apparatus receives a first transmit signal from a detection apparatus. The target apparatus generates a first echo signal by modulating some of reflected signals of the first transmit signal to cause a first Doppler shift between the first echo signal and the first transmit signal. The target apparatus emits the first echo signal to the detection apparatus, which derives its distance from the target apparatus based on the first echo signal.

A system that includes a detection device, an imaging device, and a control device is disclosed. The detection device may generate proximity data relating to a proximity of an undercarriage of a rail vehicle, and the imaging device may capture one or more thermal images of the undercarriage. The control device may receive a first thermal image and a second thermal image of the undercarriage. The first thermal image may be captured using a first integration time, and the second thermal image may be captured using a second integration time. The control device may determine composite thermal data associated with the undercarriage. The composite thermal data may include information mapping a first range of thermal data and mapping a second range of thermal data to one or more components of the undercarriage. The control device may cause an action to be performed in connection with the composite thermal data.

A system that includes a detection device, an imaging device, and a control device is disclosed. The detection device may generate proximity data relating to a proximity of an undercarriage of a rail vehicle, and the imaging device may capture one or more thermal images of the undercarriage. The control device may receive a first thermal image and a second thermal image of the undercarriage. The first thermal image may be captured using a first integration time, and the second thermal image may be captured using a second integration time. The control device may determine composite thermal data associated with the undercarriage. The composite thermal data may include information mapping a first range of thermal data and mapping a second range of thermal data to one or more components of the undercarriage. The control device may cause an action to be performed in connection with the composite thermal data.

Disclosed is a compact integrated apparatus of an interferometric radar altimeter (IRA) and a radar altimeter (RA) capable of performing individual missions by altitude, which includes: a plurality of antennas; a signal processing control unit selecting an RA mode at a low altitude and selecting an IRA mode at a high altitude based on a mode threshold and selecting an FMCW waveform at the low altitude and selecting an FM pulse waveform at the high altitude based on a waveform threshold; and a transceiving unit transmitting a signal by a first antenna positioned at an outermost portion among the plurality of antennas and receiving a signal by an nth antenna positioned at another outermost portion among the plurality of antennas in the RA mode and transmitting a signal through the first antenna and receiving signals through the plurality of antennas in the IRA mode.

Disclosed is a compact integrated apparatus of an interferometric radar altimeter (IRA) and a radar altimeter (RA) capable of performing individual missions by altitude, which includes: a plurality of antennas; a signal processing control unit selecting an RA mode at a low altitude and selecting an IRA mode at a high altitude based on a mode threshold and selecting an FMCW waveform at the low altitude and selecting an FM pulse waveform at the high altitude based on a waveform threshold; and a transceiving unit transmitting a signal by a first antenna positioned at an outermost portion among the plurality of antennas and receiving a signal by an nth antenna positioned at another outermost portion among the plurality of antennas in the RA mode and transmitting a signal through the first antenna and receiving signals through the plurality of antennas in the IRA mode.

A storage medium-compatible communications unit, a phase detection unit, a parameter acquisition section and a location detection section are provided. The storage medium-compatible communications unit communicates with a storage medium by wireless using electromagnetic waves at a predetermined frequency. The phase detection unit detects phases of signals received from the storage medium. The parameter acquisition section acquires a distance detection parameter to be used in detecting a storage medium distance from a first position of an antenna to the storage medium. The first position is a position in a range of positions of the antenna from which the distance to the storage medium is shortest. The distance detection parameter is a value set in accordance with a positional relationship between the first position and a second position. The second position is a position of the antenna in the range of positions of the antenna that is different from the first position. The location detection section detects the storage medium distance, using a first phase detected by the phase detection unit at the first position, a second phase detected by the phase detection unit at the second position, and the distance detection parameter acquired by the parameter acquisition section. The location detection section identifies the first position at a time at which a trend of changes of phase detected by the phase detection unit in association with movement of the antenna reverses.