The disclosed subject matter relates to Frequency Diversity Pulse Pair (FDPP) methods and technology implemented by, alternating the order of the pulse pair transmitted or order of the group of multiple pulses transmitted, the pulses differentiated based on the center frequency of each transmitted pulse. For example, where a pair of transmitted pulses have center frequencies f.sub.1 and f.sub.2, the pulses transmitted in pairs such that the first pair may be f.sub.1 followed by f.sub.2 and the second pair are a different order, such as f.sub.2 followed by f.sub.1.

There is provided a radar device that calculates an angle of a target based on a phase difference between reception signals obtained by receiving reflected waves from the target. A transmitting unit alternately transmits first and second transmission waves having different beam patterns. A calculating unit calculates reception levels of the reception signals, and an estimate angle at which the target is estimated to exist. A first determining unit determines a degree of reliability of a level difference between the reception levels, on the basis of a comparison between the level difference with a reference value which is associated with the estimate angle in advance. A second determining unit determines whether the target exists at the estimate angle, on the basis of a determination result and the reception level based on the first transmission wave.

An antenna device includes a plurality of antenna elements respectively configured to receive incident waves coming from an object, a modulating unit respectively configured to modulates a first received signal of the incident waves output from the antenna elements into a second received signal, the second received signals having a plurality of different frequencies and phases corresponding to polarization directions of the received incident waves, a synthesizing unit configured to synthesize the plurality of second received signals and generates a synthetic signal, a signal processing unit, configured to perform predetermined signal processing on the synthetic signal, and an extracting unit configured to extract third received signals for each frequency and each phase from the synthetic signal on which has been performed the predetermined signal processing.

In a general aspect, a radar system includes a vapor cell sensor system and a radio frequency (RF) optic. The vapor cell sensor system includes a vapor cell sensor, and the RF optic is configured to direct an RF field onto the vapor cell sensor. The RF field includes one or more RF pulses that define a radar signal. The radar system also includes a signal processing system configured to perform operations that include generating a digital signal based on a signal from the vapor cell sensor system. The digital signal represents a measured response of the vapor to the RF field over a time period. The operations also include applying a matched filter to the digital signal to generate a filtered signal and processing the filtered signal to determine properties of the RF field sensed by the vapor cell sensor over the time period.

A system and method for determining moisture content of soil, comprising providing bistatic radar configuration to measure soil reflectivity in UHF and S-band, cross-correlating between Sky-viewed and Earth-viewed signals and reflected signals in order to isolate the reflected signals, and correlating the isolated reflectesd signal to moisture content of the soil.

A radar system includes a transmit front end device including a transmit planar component, and a receive front end device including a receive planar component. Each of the transmit planar component and the receive planar component includes a first end, a second end, a cavity space and a linear array of antennas. The cavity space is bounded by beam ports along a first side of the cavity space and by array ports along a second side of the cavity space. The cavity space is in operative communication with the beam ports and with the array ports to form a Rotman lens. A linear array of antennas is located along the second end of the planar component. The transmit planar component and receive planar component are arranged such that the linear array of antennas of the transmit planar component and the linear array of antennas are perpendicular to one another.

Apparatus and associated methods relate to detecting cloud conditions from a distance by generating a polarized microwave-frequency electromagnetic pulse and evaluating various reflected wave parameters pertaining to a corresponding cloud-reflected microwave-frequency electromagnetic reflection. Various cloud metrics can be calculated using these collected wave parameters. The microwave-frequency pulses can be scanned over multiple dimensions, using a steered beam arrangement which will lead to the ability to scanning a conical sector of the space in front of the aircraft. These collected multi-dimensional wave parameters can then be used to generate multi-dimensional maps of cloud metrics. Such cloud metrics can include relative velocities of moving cloud conditions in the flight direction, particle density distributions, ice/water ratios, estimates of particle side distributions, etc.

The present invention essentially comprises a system, method, computer program and combinations thereof to utilize dual-polarization generated data generally associated with weather and non-weather events for mapping data, producing geo-referenced data, producing mosaics, generation of precipitation masks, non-precipitation mask, and classification masks in general, production of vertical cross sections and predetermined fly throughs, producing short term forecasting, prediction of specific weather phenomenon, correcting or adjusting rain gauge data as well as quantitative precipitation estimation, and combining other meteorological data to correct or adjust estimated rainfall accumulation gathered by dual-polarization radar.

Techniques and apparatuses are described that implement electromagnetic vector sensors (EMVS) for a smart-device-based radar system. Instead of including an antenna array of similar antenna elements, the radar system includes two or more electromagnetic vector sensors. At least one of the electromagnetic vector sensors is used for transmission and at least another of the electromagnetic vector sensors is used for reception. Each electromagnetic vector sensor includes a group of antennas with different antenna patterns, orientations, and/or polarizations. An overall footprint of the two electromagnetic vector sensors (e.g., one for transmission and one for reception) can be smaller than antenna arrays used by other radar systems, thereby enabling the radar system to be implemented within space-constrained devices.

An on-vehicle radar device includes a mount and an antenna configured to transmit a transmission wave from an inner side of laminated glass, which includes an innermost glass layer, an outermost glass layer, and an intermediate resin layer, and receive a reflected wave. The antenna includes a transmitting antenna. When the mount is mounted on a bracket, the incident angle of the transmission wave on the innermost glass layer is greater than a Brewster angle on the inner surface of the innermost glass layer, and the incident angle of the transmission wave on the outermost glass layer is less than or equal to a Brewster angle between the outermost glass layer and the intermediate resin layer.