Embodiments are directed to a dynamic radar detection threshold for stateful dynamic frequency selection (DFS). An embodiment of a storage medium includes instructions to operations including estimate a duty time of transmission of wireless signals by an access point, the access point to provide Wi-Fi communication, the wireless signals being communicated on a DFS channel of the access point, adapt, based at least in part on the duty time of transmission, a threshold of radar signals to indicate detection of a radar signal at the access point on the DFS channel, and perform analysis of received wireless signals on the DFS channel at the access point to detect the radar signal using the adapted threshold of radar signals.

A system and a method are provided for achieving long range, over the horizon (OTH), persistent surveillance, alerting, tracking and situational awareness against small, low radar cross section moving targets. The system and method use one or more tethered unmanned arial systems, or unmanned arial vehicles, to lift components including a radar antenna to a height above nearby obstacles or much higher. The system and method can also be used for subsurface radar detection and tracking applications, as well as communications with submarines.

Disclosed herein are related to a system and a method for determining an Angle of Approach (AoA) of a device. A first device may receive a report from a second device having a plurality of ultra-wideband (UWB) devices. The report may include a plurality of values comprising an elevation component and an azimuth component of the AoA from the first device. At least some of the plurality of values may be obtained according to measurements between the plurality of UWB devices of the second devices and the at least one UWB device of the first device. The first device may determine an AoA from the second device, using the plurality of values from the report received from the second device.

A radar apparatus includes a radar transmission circuit that transmits a radar signal from a transmission array antenna, and a radar reception circuit that receives, from a reception array antenna, a reflected wave signal that is the radar signal reflected at a target. One of the transmission array antenna and the reception array antenna includes a first antenna element group having m antenna elements arranged at a first interval D.sub.t along a first axis direction, wherein m is an integer of 2 or larger. The other one of the transmission array antenna and the reception array antenna includes a second antenna element group having n antenna elements arranged at a second interval D.sub.r along the first axis direction, wherein n is an integer of 4 or larger. The second interval D.sub.r includes several different intervals.

A resettable bracket is herein presented. The bracket is configured to mount a transceiver to a vehicle. The bracket includes a first piece and a second piece configured to be pivotably connected to each other. A docking station is mounted to the first piece. The docking station includes a bluff, an over-travel stop, and a plurality of arms configured to restrict pivotable movement of the second piece in relation to the first piece. A fitting element is mounted to the second piece. The fitting element is configured to dock into the docking station to substantially create the pivotable connection between the first and the second piece. A spring is installed at the pivotable connection between the first and second pieces. The spring is configured to allow the second piece to automatically return to a default position after being pivoted in relation to the first piece.

A system, computer program product and method of examining the ionosphere is disclosed. The method includes capturing, at one or more antennas, radio frequency (RF) emissions preceding a broadband emission event. The RF emissions are then recorded at one or more broadband receivers over a period of time. A first tuning of the received RF emissions is selected to detect ionospheric reflections, and a second tuning of the received RF emissions is selected to detect direct line of sight emissions. From the selected tunings, an amplitude or complex time series of the second tuning with one or more channels of the first tuning are correlated to calculate a relative virtual echo height of the ionosphere.

Disclosed are various embodiments for exciting a guided surface waveguide probe to create a plurality of resultant fields that are substantially mode-matched to a Zenneck surface wave mode of a surface of a lossy conducting medium and embodiments for receiving energy from a Zenneck surface wave launched on the lossy conducting medium.

A process for radiometric calibration of signals-of-opportunity (SoOps) may include adding a noise source to a plurality of input signals of a receiver, and calibrating the plurality of inputs signals with the added noise source.

Methods and apparatuses for providing wide-area surveillance with a radar and/or other sensors from a stratospheric balloon launched from a land or ship platform for detection, tracking, and classification of maritime, land, and air objects such as ships, people/vehicles, or aircraft are described generally herein. In one or more embodiments, an apparatus is battery operated and includes a stratospheric balloon filled that is filled with helium when it is launched and a gondola with a radar system and communication equipment suspended therefrom. When launched, the apparatus can travel with the wind until it reaches an altitude of approximately 68,500 ft., then it can move substantially horizontally with the stratospheric winds until it returns to earth via a parachute. Multiple apparatus launches at periodic intervals can help provide continuous coverage of the surveillance area. The apparatus can be recovered and re-used or can be considered expendable.

Disclosed is a method of mitigating the effects of anomalous propagation in a Radar system, comprising the steps of: receiving a plurality of returns from a plurality of transmit pulses; calculating a difference in magnitude between each of the plurality of returns and its successor; if one of the calculated differences indicates a first step change greater than a first predetermined threshold, calculating a first average magnitude of the returns received after the first step change, and replacing the returns received before the first step change with synthesised returns having a magnitude equal to the first calculated average magnitude.