Abstract: An optical apparatus can be configured to cover an optical transceiver. At least a portion of the apparatus can be configured to move relative to the transceiver between a block state wherein the apparatus is configured to block transmission from a transmitter of the optical transceiver to a receiver of the optical transceiver as well as block emission from the transmitter to the atmosphere, and one or more transmit states wherein the apparatus is configured to allow at least partial transmission from the transmitter of the optical transceiver to a receiver of the optical transceiver while blocking emission from the transmitter to the atmosphere.

Abstract: Apparatus and associated methods relate to determining airspeed and/or altitude based on acoustic waves caused by airflow. One of more acoustic transducers are positioned along an exterior surface of an aircraft. Each of the one or more acoustic transducers is configured to detect acoustic waves caused by the airflow. The acoustic waves detected are indicative of an airstream condition proximate the acoustic transducer, such as, for example, airspeed and/or altitude. A processor is configured to determine airspeed and/or altitude of the aircraft based, at least in part, on the acoustic waves detected.

Abstract: An acoustic sensor system for an aircraft includes a transmitter configured to emit acoustic signals external to the aircraft, and at least one microphone positioned on an exterior of the aircraft and configured to sense the acoustic signals as sensed data. The acoustic sensor system is configured to direct the acoustic signals to the at least one microphone such that a sound pressure level is attenuated perpendicular to the aircraft.

Abstract: An acoustic sensor system for an aircraft, and method for operating the same, includes a transmitter, at least one microphone, and a control circuit. The transmitter is configured to emit acoustic signals external to the aircraft. The at least one microphone is positioned on an exterior of the aircraft and configured to sense the acoustic signals as sensed data. The control circuit is configured to receive the sensed data and control the transmitter through a drive circuit, and is configured to detect an environmental condition and control the transmitter to emit the acoustic signals at a reduced intensity based on the detected environmental condition.

Abstract: An acoustic sensor system for an aircraft includes a transmitter configured to emit acoustic signals external to the aircraft, and at least one microphone positioned on an exterior of the aircraft and configured to sense the acoustic signals as sensed data. The acoustic sensor system is configured to direct the acoustic signals to the at least one microphone such that a sound pressure level is attenuated perpendicular to the aircraft.

Abstract: An acoustic sensor system for an aircraft, and method for operating the same, includes a transmitter, at least one microphone, and a control circuit. The transmitter is configured to emit acoustic signals external to the aircraft. The at least one microphone is positioned on an exterior of the aircraft and configured to sense the acoustic signals as sensed data. The control circuit is configured to receive the sensed data and control the transmitter through a drive circuit, and is configured to detect an environmental condition and control the transmitter to emit the acoustic signals at a reduced intensity based on the detected environmental condition.