A system and method to control a vehicle, provides for directing light onto a region of a road surface on which the vehicle is moving. A variation in a characteristic of a reflection of the directed light is determined. Accumulated precipitation is detected on at least the region of the road based on the determined variation.

A remote reflective materials sensor for detecting remotely located reflective material. The remote reflective materials sensor includes a transparent window with two window surfaces, an amount of reflective material that is remotely located away from one window surface. An operating parameters sensor located adjacent to the transparent window, a radiation detector located away from the other window surface; and two spaced apart radiation emitters located on either side of the radiation detector, and away from the second window surface. Each radiation emitter is configured to emit radiation along one axis through the transparent window towards the reflective material and towards a common focal point. The radiation detector is located to receive reflected radiation from the reflective material along another axis. The first axis of the radiation emitters is angled towards the other axis of the reflected radiation.

The present invention relates to a system (S) and a process for determining the water equivalent content of a snowpack (Snow Water EquivalentSWE).

Aspects of the present disclosure include systems and methods for determining the loss of an unknown channel through remote wireless interrogation of a nonlinear transponder. The transponder's nonlinearity is leveraged to ascertain an operating point of the nonlinear transponder. In some examples the operating point is determined by interrogating a nonlinear transponder with an interrogation signal containing two closely spaced frequencies and measuring intermodulation distortion and/or other components of a return signal that nonlinear transponder backscatters. In some examples, an operating point is determined by interrogating the transponder with an amplitude-modulated interrogation signal, comprising a carrier frequency modulated with at least one second frequency and measuring components of a return signal backscattered by the nonlinear transponder. With an operating point determined, channel losses and material properties of an environment in which the transponder is located, among other things, can be determined.

The present application discloses systems and methods for detecting a frost condition using a water temperatures sensor on an autonomous vehicle. The water temperature sensor includes a wind tunnel tube forming a hollow path for an airflow. The system further includes a fluid valve coupled to a fluid reservoir to dispense a fluid into the airflow of the hollow path. The water temperature further includes wet-bulb temperature sensor affixed to a vent coupled to a distal end of the wind tunnel tube. The wet-bulb temperature sensor configured to capture sensor data indicating a frost condition.