Abstract: A three-dimensionally designed display radar in which a two-dimensional image data and three-dimensionally designed image data are depicted in combination in a video memory by the aid of an image controller, and they are simultaneously depicted on a screen of a display unit.

Abstract: A fish finder having two 1D transducer arrays vertically arranged on a ship's hull. Each 1D transducer array provides a beam having a narrow width on a plane parallel to a plane in the transducer arrangement direction, and a fan-like beam on a plane crossing the plane. Ultrasonics are transmitted toward and received from the target on the first plane, by using the fan beam of the first 1D transducer array, and received from the second plane perpendicular to the first plane by using the fan beam of the second 1D transducer array. While the beam direction of the first 1D transducer array is gradually changed, that of the second 1D transducer array is rapidly changed so that information concerning the 3D space below the water surface is obtained. The obtained information is subjected to ray tracing processing for 3D displaying of an image on a 2D screen. This arrangement enables quicker detection of fish schools.

Abstract: A GPS signal receiver has a PN code generator for producing a PN code identical to a PN code in a received GPS signal which is transmitted from a GPS satellite, the PN code produced by the PN code generator being controllable in phase, a PN code correlator for correlating the received GPS signal with the PN code produced by the PN code generator so as to code-strip the received GPS signal, a signal search unit for monitoring a correlated output signal from the PN code correlator and controlling the phase of the PN code produced by the PN code generator to search for a correlated output signal in excess of a predetermined value, a signal determining unit for determining the correlated output signal in excess of the predetermined value as being produced by a direct wave of the GPS signal, and a signal tracking unit for controlling the phase of the PN code produced by the PN code generator to track a peak of the correlated output signal that is determined as being produced by the direct wave of the GPS signal.

Abstract: Disclosed herein is a three-dimensional display radar, which comprises a radar transmitter-receiver unit for producing signals indicative of information about a bearing of a target, information about distance to the target and information about the received power reflected from the target, respectively, a display, a three-dimensional coordinate converter for converting the bearing information, the distance information and the received power information into signals indicative of both an X-Y coordinate and the height of the target, marker generator for generating range marker signals when the target is three-dimensionally represented on a screen of the display, and a video memory having storage addresses corresponding to respective pixels on the display and for storing the received power information at a storage address corresponding to the X-Y coordinate obtained from the three-dimensional coordinate converter and storing therein the marker signals generated from the marker generator, the video memory being f

Abstract: A GPS receiver apparatus retrieves a maximum correlation point between a PN code involved in a satellite signal and a generated PN code with use of n detecting means each concurrently processing the retrieval operation to acquire the PN code of the satellite signal. The apparatus acquires the PN code of the satellite signal, unless said maximum correlation is yielded, by effecting a correlation processing or taking the synchronization among phases of the PN code in which the generated PN code is shifted in its phase by n/2 bits to retrieve the maximum correlation point. The apparatus further tracks GPS radiowaves with the use of a plurality of said detecting means which has been used to acquire the PN code.

Abstract: In a global positioning system (GPS)/self-contained combination type navigation system for a vehicle, the GPS navigation data are received by the GPS antenna of the navigation system which are simultaneously transmitted from more than 3 pieces of satellites inclusively. From the GPS navigation data, GPS type velocity data is calculated, whereas self-contained type velocity data is calculated from self-contained type navigation data such as azimuth data and drive-distance data of the vehicle. Only when a difference between the self-contained type velocity data and the GPS type velocity data exceeds a threshold velocity, the GPS type velocity data is voided so as to determine the present position of the vehicle.

Abstract: An apparatus to confirm an orientation of the stem of ship by making use of a satellite included in the Global Positioning System. Radio wave signals from the satellite are received by a directional or omnidirectional antenna and the phase difference between a rotating period of said antenna and either the period of distance fluctuation, Doppler fluctuation, phase fluctuation or amplitude fluctuation is detected to obtain an orientation of the satellite which is used to obtain an accurate orientation of the stem relative to a reference direction such as due North.