An environment measurement system according to the present invention is provided with a first unit comprising: a transmitter which is located undersea and transmits an acoustic wave in a designated direction a plurality of times; a first receiver which is located undersea and receives an acoustic wave reflected by a reflecting body at the sea surface or the seabed; a transmission direction setting unit which designates, to the transmitter, transmission directions specified in advance by a user, so as to cause the transmitter to transmit acoustic waves in the directions; a first necessary time measurement unit which, for each of the transmission directions, measures from the transmission and reception times of an acoustic wave a time necessary for the acoustic wave to return, as a necessary time, and outputs an average of the measured necessary time as an average necessary time for each of the transmission directions; a layer setting unit which partitions between the sea surface and the seabed into layers each extending horizontally, at intervals of preset distances; a simultaneous equations set-up unit which sets up simultaneous equations using the transmission directions, the necessary times and the layer thicknesses and taking average sound velocities in the respective layers as unknown variables; a simultaneous equations solving unit which solves the simultaneous equations; an initial parameter setting unit which sets initial values necessary for the simultaneous equations solving unit to solve the simultaneous equations, as parameter initial values; and a sound velocity profile output unit which creates a profile of sound velocities obtained by determining solutions acquired by the simultaneous equations solving unit to be average sound velocities in the respective layers and arranging the average sound velocities in the respective layers in order of depth, and outputs the profile.

A marine sonar display device comprises a display, a sonar element, a multi axis sensor, a memory element, and a processing element. The display presents sonar images. The sonar element generates a sonar beam. The multi axis sensor determines an orientation and a tilt of the sonar element and present a sensor signal indicating the orientation and the tilt. The processing element is in communication with the display, the sonar element, the multi axis sensor, and the memory element. The processing element further determines an operating mode of the marine sonar display device, wherein the operating mode varying according to the orientation and the tilt of the sonar element.

A marine sonar display device comprises a display, a sonar element, a multi axis sensor, a memory element, and a processing element. The display presents sonar images. The sonar element generates a sonar beam. The multi axis sensor determines an orientation and a tilt of the sonar element and present a sensor signal indicating the orientation and the tilt. The processing element is in communication with the display, the sonar element, the multi axis sensor, and the memory element. The processing element further determines an operating mode of the marine sonar display device, wherein the operating mode varying according to the orientation and the tilt of the sonar element.

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 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.