Abstract:
A time transmission method using a GNSS(Global Navigation Satellites System) is provided to make high-precision time transmission of the nanosecond level possible by enabling an earth station to receive GNSS satellite signals. An earth station uses precise ephemeris to secure information about the location of a GNSS satellite(S10), and then performs the pre-processing for removing abnormal data of satellite signals which have a cycle slip and a lower angle of elevation, for selecting an unknown parameter which will be estimated according to each GNSS satellite session, and for transmitting the primary time information which has lower precision(S20). The earth station performs statistical estimation of the selected unknown parameter in real-time type or post-processing type, executes precision time transmission between earth stations in each GNSS satellite, and then determines the final time comparison value(S30).
Abstract:
A reference time provision system using a beacon signal of a DGPS(Differential Global Positioning System) is provided to supply exact reference time by feeding back time delay generated in passing through a base station system and an antenna. A reference time provision system using a beacon signal of a DGPS is composed of a reference time output unit for generating and outputting reference time, and a DGPS unit(100) for transmitting time information together with the beacon signal on the basis of the reference time output from the reference time output unit. The reference time output unit has a calibration unit for compensating time delay generated in transmitting and receiving the time information. The calibration unit comprises a GPS clock unit(320); a DBR(DGPS Beacon Receiver,300) receiving an electric wave transmitted from the DGPS unit; a comparing unit comparing the time output from the GPS clock unit with the time received through the time information receiver; and a feedback unit feeding back the comparison result of the comparing unit to the reference time output unit.
Abstract:
PURPOSE: Measuring method and device for three-dimensional movement are provided to conveniently and precisely measure movement and transformation of a structure. CONSTITUTION: An initial image and a measured image are inputted through a CCD(Charge Couple Device) camera. A computer receives the images for checking location of a laser beam by using an image processing operation. A relative location between reference points formed by luminous diodes and the lower beam is measured. A pixel satisfying a minimum error is calculated for deciding a minimum value of an offset. Therefore, a displacement of an initial established value is measured through calculating the pixel of the minimum offset. Herein, the camera having 410 thousand pixels and 32 magnifications is used.
Abstract:
PURPOSE: Measuring method and device for three-dimensional movement are provided to conveniently and precisely measure movement and transformation of a structure. CONSTITUTION: An initial image and a measured image are inputted through a CCD(Charge Couple Device) camera. A computer receives the images for checking location of a laser beam by using an image processing operation. A relative location between reference points formed by luminous diodes and the lower beam is measured. A pixel satisfying a minimum error is calculated for deciding a minimum value of an offset. Therefore, a displacement of an initial established value is measured through calculating the pixel of the minimum offset. Herein, the camera having 410 thousand pixels and 32 magnifications is used.
Abstract:
다중변조 및 시분할 전송기술을 이용한 단파 표준시 전송장치, 전송방법, 전송시스템 및 그 기록매체에 관한 것이다. 보다 상세하게는,단파 표준시 전송장치에 있어서, 타임코드를 발생시키는 타임코드 발생기; 타임코드에서 발생된 타임코드를 전송받아 AM신호로 변조시키는 AM변조기; 타임코드에서 발생된 타임코드를 전송받아 FSK신호로 변조시키는 FSK변조기; AM변조기에서 발생되는 AM신호 또는 FSK변조기에서 발생되는 FSK신호를 선택하는 선택수단; 타임코드발생기, AM변조기 및 FSK변조기에 단파신호를 인가하는 기준주파수 입력기; 및 선택수단에 의해 선택된 AM신호 또는 FSK신호를 송신하는 송신기;를 포함하는 것을 특징으로 하는 다중변조 및 시분할 전송기술을 이용하여 기존의 AM 사용자를 보호하면서 FSK에 의한 타임코드를 수신기가 환경에 따라 선택적으로 수신이 가능하도록 하는 단파 표준시 전송장치에 대한 것이다.
Abstract:
본 발명은 정밀도를 요하는 시각정보시스템에 관한 것으로서, 더욱 상세하게는 소프트웨어 클럭시뮬레이터를 이용하여 보다 정밀한 시각정보를 제공하는 시각 정보시스템에 관한 것이다. 본 발명에 따른 클럭시뮬레이션 방법은 클럭의 운용에 관한 입력, 클럭의 거동에 관한 입력, 클럭의 제어에 관한 입력을 사용자로 부터 입력받는 단계와, 상기 입력된 데이터를 바탕으로 운용관련입력을 내부변수화하고, 거동관련입력을 다항식 계수화 및 h-매개변수화하고, 제어관련 입력인 제어명령에 대해 제어주파수를 산출하는 초기화단계와, 초기화된 데이터를 바탕으로 시간간격에 맞추어 다항식계수와 제어명령으로부터 결정적 추세를 계산하고, h-매개변수로부터 여러 잡음 성분을 생성하여 합산하는 단계와, 시뮬레이션 종료시간까지 합산 단계를 반복하여 기준시각에 대해 클럭 출력을 정렬하여 사용자에게 제공하는 단계를 포함하는 것을 특징으로 한다. 클럭시뮬레이터, 항법 위성, 통신, 주파수원, 결정적 추세, 추계적 잡음
Abstract:
A method for simultaneously comparing international standard time by using a satellite-based code division technique is provided to enable all time comparison organs participating in a time comparison link to simultaneously perform multi-channel time comparison, thereby simultaneously and exactly comparing the standard time of nations, which can be covered by a communication satellite, such as Asia, Europe, America and so on. A master station of a time synchronous network transmits a message for transmission start to the whole slave stations participating in the time synchronous network(S10). Time comparison participating nations, receiving the message, transmit intrinsic individual signals to the master station through a satellite(S20). The master station remotely controls power of the individual signals of the slave stations(S30). After the control process is completed, time comparison between earth stations is performed(S40). After that, all information of all earth stations including the time comparison result obtained at each earth station is exchanged with time comparison participation standard organs(S50).
Abstract:
A GPS(Global Positioning System) antenna device for preventing jamming and a receiving method thereof are provided to normally operate a receiver even if power of an intentional jamming signal or an unintentional jamming signal, such as interference of an electric wave generated from various communication facilities, is out of an allowable range of an amplifier of a GPS antenna. A GPS antenna device for preventing jamming is composed of plural GPS antennas(20b~20n) installed around a first GPS antenna(20a) to receive GPS signals of each assigned region; power detectors(30a~30n) connected to the respective GPS antennas in series to detect the power level of signals received from the GPS antennas; switches(35a~35n) connected to the respective power detectors in series and opened or closed on the basis of the power level detected by the power detector; amplifiers(40a~40n) connected to the output side of the respective switches in series; adders(50) adding up signals amplified by the amplifier; and a GPS receiver(60) connected to the output side of the adder.