Abstract: Active surface structures comprise an exposed surface, a controlled group of MEMS (micro-electro-mechanical system) actuators, and a controlled region of the exposed surface corresponding to the controlled group. The controlled region has a first state, and a second state that is less textured than the first state. Active surface structures may be part of an apparatus that includes a controller and/or one or more sensors. The controller, sensors, and the controlled region may form a feedback loop in which the active surface structure is actively controlled.

Abstract: Apparatuses, systems, and methods for open path laser spectroscopy with mobile platforms. An example system may include a first mobile platform and a second mobile platform, each of which supports a payload. A light beam directed from one payload to another may define a measurement path, which may be at a particular height above the ground. The payloads may determine a gas concentration along the measurement path. Wind information at the measurement height may be used to determine a gas flux. One or both of the mobile platforms may then move to a new location, and take a measurement along a new measurement path. By combining the measurement paths, gas flux through a flux surface may be determined.

Abstract: Embodiments of the disclosure are drawn to apparatuses and methods for a rotating optical reflector. Optical systems may have a limited field of view, and so in order to expand the area that the optical system collects data from, the field of view of the optical system may be scanned across a target area. The present disclosure is directed to a rotating optical reflector, which includes a transmissive layer which refracts light onto a reflective layer, which has a normal which is not parallel to the axis about which the optical reflector is rotated. The optical reflector may be both statically and dynamically balanced, which may allow an increased size of the optical reflector, which in turn may increase the aperture of an optical system (e.g., a lidar system) using the rotating optical reflector.

Abstract: Apparatuses, systems, and methods for open path laser spectroscopy with mobile platforms. An example system may include a first mobile platform and a second mobile platform, each of which supports a payload. A light beam directed from one payload to another may define a measurement path, which may be at a particular height above the ground. The payloads may determine a gas concentration along the measurement path. Wind information at the measurement height may be used to determine a gas flux. One or both of the mobile platforms may then move to a new location, and take a measurement along a new measurement path. By combining the measurement paths, gas flux through a flux surface may be determined.

Abstract: Embodiments of the disclosure are drawn to apparatuses and methods for a rotating optical reflector. Optical systems may have a limited field of view, and so in order to expand the area that the optical system collects data from, the field of view of the optical system may be scanned across a target area. The present disclosure is directed to a rotating optical reflector, which includes a transmissive layer which refracts light onto a reflective layer, which has a normal which is not parallel to the axis about which the optical reflector is rotated. The optical reflector may be both statically and dynamically balanced, which may allow an increased size of the optical reflector, which in turn may increase the aperture of an optical system (e.g., a lidar system) using the rotating optical reflector.

Abstract: Embodiments of the disclosure are drawn to apparatuses and methods for a rotating optical reflector. Optical systems may have a limited field of view, and so in order to expand the area that the optical system collects data from, the field of view of the optical system may be scanned across a target area. The present disclosure is directed to a rotating optical reflector, which includes a transmissive layer which refracts light onto a reflective layer, which has a normal which is not parallel to the axis about which the optical reflector is rotated. The optical reflector may be both statically and dynamically balanced, which may allow an increased size of the optical reflector, which in turn may increase the aperture of an optical system (e.g., a lidar system) using the rotating optical reflector.

Abstract: Examples of FMCW laser radar systems and methods described herein may segment the processing of a broader bandwidth frequency chirp into multiple shorter-duration (e.g., lower bandwidth) frequency chirps. This segmentation may have the benefits in some examples of improving the measurement duty cycle and range resolution, and/or allowing for more flexible processing, and/or enabling improved detection of more distant objects.

Abstract: Embodiments of the disclosure are drawn to apparatuses and methods for a rotating optical reflector. Optical systems may have a limited field of view, and so in order to expand the area that the optical system collects data from, the field of view of the optical system may be scanned across a target area. The present disclosure is directed to a rotating optical reflector, which includes a transmissive layer which refracts light onto a reflective layer, which has a normal which is not parallel to the axis about which the optical reflector is rotated. The optical reflector may be both statically and dynamically balanced, which may allow an increased size of the optical reflector, which in turn may increase the aperture of an optical system (e.g., a lidar system) using the rotating optical reflector.

Abstract: Active surface structures comprise an exposed surface, a controlled group of MEMS (micro-electro-mechanical system) actuators, and a controlled region of the exposed surface corresponding to the controlled group. The controlled region has a first state, and a second state that is less textured than the first state. Active surface structures may be part of an apparatus that includes a controller and/or one or more sensors. The controller, sensors, and the controlled region may form a feedback loop in which the active surface structure is actively controlled.

Abstract: Active superhydrophobic surface structures are actively-controlled surface structures exhibiting a superhydrophobic state and an ordinary state. Active superhydrophobic surface structures comprise an outer elastomeric covering defining an exposed surface, a controlled group of MEMS (micro-electro-mechanical system) actuators at least covered by the elastomeric covering, and, a controlled region of the exposed surface corresponding to the controlled group. The controlled region has a superhydrophobic state in which the controlled region is textured. The controlled region also has an ordinary state in which the controlled region is smooth (i.e., less textured than in the superhydrophobic state). Active superhydrophobic surface structures may be part of an apparatus that includes a controller and/or one or more sensors. The controller, sensors, and the controlled region may form a feedback loop in which the active superhydrophobic surface is actively controlled.

Abstract: Examples are provided that use multiple analog-to-digital converters (ADCs) to disambiguate FMCW ladar range returns from one or more targets that may be greater than the Nyquist frequencies of one or more of the ADCs. Examples are also provided that use a first and a second laser FMCW return signal (e.g., reflected beam) in combination with two or more ADCs to disambiguate one or more target ranges (e.g., distances to one or more objects).

Abstract: Methods and apparatuses are described for frequency-modulated continuous-wave (FMCW) light detection and ranging (LiDAR). Examples are provided where high-closed-loop bandwidth, active feedback applied to laser frequency chirps may provide increases in the free-running laser coherence length for long-range FMCW distance measurements. Examples are provided that use an asymmetric sideband generator within an active feedback loop for higher closed-loop bandwidth. Examples of using a single shared reference interferometer within multiple active feedback loops that may be used for increasing the coherence length of multiple chirped lasers are described. Example calibrators are also described.

Abstract: Apparatuses, systems, and methods for open path laser spectroscopy with mobile platforms. An example system may include a first mobile platform and a second mobile platform, each of which supports a payload. A light beam directed from one payload to another may define a measurement path, which may be at a particular height above the ground. The payloads may determine a gas concentration along the measurement path. Wind information at the measurement height may be used to determine a gas flux. One or both of the mobile platforms may then move to a new location, and take a measurement along a new measurement path. By combining the measurement paths, gas flux through a flux surface may be determined.

Abstract: Embodiments of the disclosure are drawn to apparatuses and methods for a rotating optical reflector. Optical systems may have a limited field of view, and so in order to expand the area that the optical system collects data from, the field of view of the optical system may be scanned across a target area. The present disclosure is directed to a rotating optical reflector, which includes a transmissive layer which refracts light onto a reflective layer, which has a normal which is not parallel to the axis about which the optical reflector is rotated. The optical reflector may be both statically and dynamically balanced, which may allow an increased size of the optical reflector, which in turn may increase the aperture of an optical system (e.g., a lidar system) using the rotating optical reflector.

Abstract: Examples are provided that use multiple analog-to-digital converters (ADCs) to disambiguate FMCW ladar range returns from one or more targets that may be greater than the Nyquist frequencies of one or more of the ADCs. Examples are also provided that use a first and a second laser FMCW return signal (e.g., reflected beam) in combination with two or more ADCs to disambiguate one or more target ranges (e.g., distances to one or more objects).

Abstract: Examples of FMCW laser radar systems and methods described herein may segment the processing of a broader bandwidth frequency chirp into multiple shorter-duration (e.g., lower bandwidth) frequency chirps. This segmentation may have the benefits in some examples of improving the measurement duty cycle and range resolution, and/or allowing for more flexible processing, and/or enabling improved detection of more distant objects.

Abstract: Methods and apparatuses are described for frequency-modulated continuous-wave (FMCW) light detection and ranging (LiDAR). Examples are provided where high-closed-loop bandwidth, active feedback applied to laser frequency chirps may provide increases in the free-running laser coherence length for long-range FMCW distance measurements. Examples are provided that use an asymmetric sideband generator within an active feedback loop for higher closed-loop bandwidth. Examples of using a single shared reference interferometer within multiple active feedback loops that may be used for increasing the coherence length of multiple chirped lasers are described. Example calibrators are also described.

Abstract: Active superhydrophobic surface structures are actively-controlled surface structures exhibiting a superhydrophobic state and an ordinary state. Active superhydrophobic surface structures comprise an outer elastomeric covering defining an exposed surface, a controlled group of MEMS (micro-electro-mechanical system) actuators at least covered by the elastomeric covering, and, a controlled region of the exposed surface corresponding to the controlled group. The controlled region has a superhydrophobic state in which the controlled region is textured. The controlled region also has an ordinary state in which the controlled region is smooth (i.e., less textured than in the superhydrophobic state). Active superhydrophobic surface structures may be part of an apparatus that includes a controller and/or one or more sensors. The controller, sensors, and the controlled region may form a feedback loop in which the active superhydrophobic surface is actively controlled.

Abstract: Active superhydrophobic surface structures are actively-controlled surface structures exhibiting a superhydrophobic state and an ordinary state. Active superhydrophobic surface structures comprise an outer elastomeric covering defining an exposed surface, a controlled group of MEMS (micro-electro-mechanical system) actuators at least covered by the elastomeric covering, and, a controlled region of the exposed surface corresponding to the controlled group. The controlled region has a superhydrophobic state in which the controlled region is textured. The controlled region also has an ordinary state in which the controlled region is smooth (i.e., less textured than in the superhydrophobic state). Active superhydrophobic surface structures may be part of an apparatus that includes a controller and/or one or more sensors. The controller, sensors, and the controlled region may form a feedback loop in which the active superhydrophobic surface is actively controlled.

Abstract: A disclosed subsurface imaging method begins by obtaining initial signals from a geophysical survey that has been acquired with multiple geophysical energy sources actuated in a plurality of firing sequences, each sequence having a known time delay between the firing times of each source. The initial signals are grouped into gathers of signals acquired from multiple firing sequences. For each gather, initial estimates of the first and second source wave fields are determined. Quieted signals for the first source are then generated to represent the initial signals minus a current estimate of the second source wave field. A coherent energy separation operation is applied to the quieted signals to obtain a refined estimate for the first source wave field.