A device for scattered light measurement of particles in a gas, comprising a light source, a beam splitter which splits a light beam emitted by the light source into a measuring beam and a reference beam, a light receiving device arranged at a distance from the beam splitter, which comprises at least one lens arranged in the reference beam with an optical axis aligned at an acute angle to the measuring beam, a first light receiver on the side of the lens facing away from the beam splitter, for receiving the scattered light imaged by the latter from a measurement volume in a gas-bearing region between the beam splitter and the lens, and a second light receiver on the side of the lens facing away from the beam splitter for receiving the reference beam imaged by the latter.

A vehicle sensor assembly includes an optical sensor surface, at least two transducers arranged to input energy into the optical surface to produce an energy wave through the optical sensor surface and sense an attribute of an energy wave within the optical sensor surface. A controller arranged to drive the at least two transducers to input energy into the optical surface to produce an energy wave within the optical sensor surface to dislodge debris from the optical sensor surface.

An infrared (IR) imaging system for determining a concentration of a target species in an object is disclosed. The imaging system can include an optical system including a focal plane array (FPA) unit behind an optical window. The optical system can have components defining at least two optical channels thereof, said at least two optical channels being spatially and spectrally different from one another. Each of the at least two optical channels can be positioned to transfer IR radiation incident on the optical system towards the optical FPA. The system can include a processing unit containing a processor that can be configured to acquire multispectral optical data representing said target species from the IR radiation received at the optical FPA. One or more of the optical channels may be used in detecting objects on or near the optical window, to avoid false detections of said target species.

A contamination sensor for an optical sensor observation window includes a source, two prisms, a detector, and a controller. The source can emit a collimated light beam at an incident angle that is greater than a critical angle of an interface between a fluid and the window. The window has a refractive index greater than the refractive index of the fluid. The prisms can direct the collimated light beam within the window such that the collimated light beam reflects within a contamination detection zone of the window. The detector can receive the collimated light beam. The controller can communicate with the source and detector. The controller can calculate an emission/detection ratio defined by a difference between an amount of light emitted by the source and an amount of light that passes from the source to the detector by a total internal reflectance of the window.

Systems and methods are disclosed for identifying a dirty camera in a monocular camera comprising n cameras. For each of one or more cycles, a dirty counter variable for each of the n cameras is set to 0. For each of the n cameras, an image is captured from the camera and an image metric is determined for the image, e.g. brightness and/or contrast. If the image metric is 10% greater, or 10% less, than the image metric for any of the other n−1 cameras in the monocular camera, then that camera is determined to be dirty and a corrective action is taken, such as sending an alarm to an occupant the vehicle or initiating a cleaning operation. If the dirty condition persists for a camera that has been cleaned within a threshold period of time (i.e., recently), then an alarm is sent to an operator of the vehicle.

A system to localize debris on an optical surface of a vehicle includes a first array along a first side of a perimeter of the optical surface and including a light source to emit light into a thickness of the optical surface. A second array is along a second side of the perimeter, opposite the first side, and includes a light detector to detect light scatter in the thickness and provide a corresponding output. A third array is along a third side of the perimeter and includes a light source to emit light. A fourth array is along a fourth side of the perimeter, opposite the third side, and includes a light detector to detect light scatter and provide a corresponding output. A controller identifies a presence of the debris, determines a position of the debris based on the output from the light detectors, and remediates the debris.

An optical system may include an objective lens system having a primary optical axis and a relay lens system having a relay optical axis. The relay optical axis may have a first angular offset with respect to the primary optical axis. The objective lens system may be configured to provide light from a light source to the relay lens system and provide light from the relay lens system to an image sensor. The relay lens system may be configured to provide light from the objective lens system to an end face of an optical fiber, where the end face has a second angular offset with respect to a cross-sectional axis of the optical fiber. The relay lens system may provide light reflected from the end face to the objective lens system.

An optical system may include an objective lens system having a primary optical axis and a relay lens system having a relay optical axis. The relay optical axis may have a first angular offset with respect to the primary optical axis. The objective lens system may be configured to provide light from a light source to the relay lens system and provide light from the relay lens system to an image sensor. The relay lens system may be configured to provide light from the objective lens system to an end face of an optical fiber, where the end face has a second angular offset with respect to a cross-sectional axis of the optical fiber. The relay lens system may provide light reflected from the end face to the objective lens system.

An infrared (IR) imaging system for determining a concentration of a target species in an object is disclosed. The imaging system can include an optical system including a focal plane array (FPA) unit behind an optical window. The optical system can have components defining at least two optical channels thereof, said at least two optical channels being spatially and spectrally different from one another. Each of the at least two optical channels can be positioned to transfer IR radiation incident on the optical system towards the optical FPA. The system can include a processing unit containing a processor that can be configured to acquire multispectral optical data representing said target species from the IR radiation received at the optical FPA. One or more of the optical channels may be used in detecting objects on or near the optical window, to avoid false detections of said target species.

A contamination sensor for an optical sensor observation window includes a source, two prisms, a detector, and a controller. The source can emit a collimated light beam at an incident angle that is greater than a critical angle of an interface between a fluid and the window. The window has a refractive index greater than the refractive index of the fluid. The prisms can direct the collimated light beam within the window such that the collimated light beam reflects within a contamination detection zone of the window. The detector can receive the collimated light beam. The controller can communicate with the source and detector. The controller can calculate an emission/detection ratio defined by a difference between an amount of light emitted by the source and an amount of light that passes from the source to the detector by a total internal reflectance of the window.