A measuring device is provided, having a housing having a circuit board and processor; a first transducer arranged on a surface of the housing and configured to transmit an ultrasonic pulse towards a target surface; a second transducer adjacent to the first transducer configured to receive a reflection of the ultrasonic pulse off of the target surface; and a thermistor on the surface of the housing adjacent to the first and second transducers and configured to measure air temperature surrounding the device. The processor of the device is configured to measure a time duration between transmitting the ultrasonic pulse by the first transducer and receiving the reflection of the ultrasonic pulse by the second transducer, and to determine a distance between a ground surface upon which the device is resting and the target surface based at least upon the measured time duration and the measured air temperature.

A system is provided for imaging an underwater environment. The system includes one or more arrays of transducer elements. Each array is operated at a fixed phase shift and varies in frequency so as to beamform multiple sonar return beams of a first range of angles and a second range of angles. The arrays can be oriented to cover the gap in sonar coverage for other arrays to create a continuous arc of sonar coverage. Accordingly, a 2D live sonar image can be formed. One or more of the multiple sonar return beams facing downwardly can be selected and used to form downward sonar images that anglers are used to, without requiring separate transducer elements. Fish arches formed using multiple sonar return beams can be positioned appropriately within a high resolution downward sonar image to form a desirable combined sonar image.

A target object detection device is provided. The device includes a signal processor, a display unit, and a controller. The signal processor receives a reception signal generated based on an echo of an ultrasonic wave from a target object and generates echo data corresponding to a distance from a transmission source of the ultrasonic wave to the target object every time the ultrasonic wave is transmitted. The display unit has a display screen with a first side and a second side that is turnable in an axial direction perpendicular to the display screen, and displays an image on the display screen based on the echo data. The controller sets a range with respect to time at which the ultrasonic wave is transmitted, and outputs the echo data corresponding to the ultrasonic wave within the time range according to turning of the display screen.

A detection apparatus is provided. The detection apparatus includes a hardware processor programmed to at least calculate a first echo intensity of a first reception signal generated from a reception wave reflected on reflection objects, calculate a second echo intensity of a second reception signal generated from a reception wave reflected on the reflection objects, a signal duration of the second reception signal being shorter than that of the first reception signal, generate a first frequency distribution of the first echo intensity, generate a second frequency distribution of the second echo intensity, and extract a density of the reflection objects or an index of density of the reflection objects based on a comparison of the first frequency distribution and the second frequency distribution.