Serwis Infona wykorzystuje pliki cookies (ciasteczka). Są to wartości tekstowe, zapamiętywane przez przeglądarkę na urządzeniu użytkownika. Nasz serwis ma dostęp do tych wartości oraz wykorzystuje je do zapamiętania danych dotyczących użytkownika, takich jak np. ustawienia (typu widok ekranu, wybór języka interfejsu), zapamiętanie zalogowania. Korzystanie z serwisu Infona oznacza zgodę na zapis informacji i ich wykorzystanie dla celów korzytania z serwisu. Więcej informacji można znaleźć w Polityce prywatności oraz Regulaminie serwisu. Zamknięcie tego okienka potwierdza zapoznanie się z informacją o plikach cookies, akceptację polityki prywatności i regulaminu oraz sposobu wykorzystywania plików cookies w serwisie. Możesz zmienić ustawienia obsługi cookies w swojej przeglądarce.
This paper introduces the design of a near realtime BDS/GPS time transfer method. A Beidou data communication module is assembled into a time transfer receiver. The clock difference computation procedure is modified and a customized protocol is designed for comparison data exchange. The time difference of zero-baseline common-clock by GPS and BDS is compared. The performance of this method is almost...
Nowadays time and frequency transfer through optical fiber become more important with its further reduction of uncertainty. A two-way time comparison via optical fiber experiment that utilizes the carrier phase of the transmitted signal has been done at Beijing Institute of Radio Metrology and Measurement (BIRMM) laboratory. The principle and equipments are similar to the well-known two-way satellite...
This paper develops a novel real time cycle slip detection and repair method for a single dual-frequency GNSS receiver. This method is based on several carrier-phase linear combinations, including WL (1, −1), Ultra-WL (-3, 4), NL (1, 1), GF (60,-77). First, we use the mean code range rate which is estimated by the former 10 code range data to detect and repair the big cycle slip. In this step, the...
In this paper, a new defined modem with Flexible Binary Offset Carrier (FBOC) signal has been developed by the Beijing Institute of Radio Metrology and Measurement (BIRMM), we demonstrate our work details on receiving the FBOC signal. We realize it based on the FPGA and DSP hardware platform. A structure of three loops to solve the tracking ambiguous problem is also demonstrated. To evaluate the performance...
The authors are developing a portable CPT atomic clock, trying to refine the firmware to reduce power, improve performance, and ensure reliable operation over the expected range of environmental conditions. The overall volume of the physics package is less than 2 cm3, with resonance cell size of φ3mmx3mm, filled with Rb atomics and buffer gases. The portable CPT atomic clock is a complete packaged...
Considering all integration methods currently available for global positioning system (GPS) and inertial navigation system (INS) integrated navigation system, ultra-tightly coupled (UTC) GPS/INS system is the best choice for accurate and robust navigation. However the performance of UTC GPS/INS system based on scalar tracking (ST) degrades in severe jamming environments. To solve this problem an innovative...
Last year the zero-baseline common-view test using BeiDou Navigation Satellite system (BDS) is done in BIRMM and the result is better than 5 ns. In this year, we have developed our own GPS/BD common view time and frequency transfer receiver. Using this receiver we carried out two remote common view experiments in BIRM-SIMT link and BIRM-NTSC link, separately. Besides, we took out TWSTFT experiment...
The Calibration Device is used to measure the time delay difference between the transmission and receiving paths inside Two-Way Satellite Time and Frequency Transfer (TWSTFT) earth station, it can improve the time comparison precision. A new calibration device for TWSTFT has been developed recently at Beijing Institute of Radio Metrology and Measurement (BIRMM). The signal paths inside calibration...
This paper describes a time transfer system that allows timing laboratories, including metrology institutes and other designated institutions, to compare the local realization of Coordinated Universal Time (UTC) with each other. The time transfer system could calculate the difference between the local time and GPS time, and the difference between the local time and BDS time. It stores the measurement...
A new time transfer modem for two-way satellite time and frequency transfer (TWSTFT) has been developed recently at Beijing Institute of Radio Metrology and Measurement (BIRMM). The DSSS and BPSK modulation techniques are used to generate a PRN signal. A FFT fast parallel algorithm is applied to achieve fast acquisition of the PRN modulated receiving signal. A 2nd order FLL assisted 3rd order PLL...
A new mathematical method is proposed to convert the oscillator instability parameters from Allan variance to Spectrum Density (SD) of random phase fluctuations, which is the inversion of the classic transformation formula from SD to Allan variance. Due to the fact that Allan variance does not always determine a unique SD function, Power-law model of the SD of oscillator phase fluctuations is introduced...
Podaj zakres dat dla filtrowania wyświetlonych wyników. Możesz podać datę początkową, końcową lub obie daty. Daty możesz wpisać ręcznie lub wybrać za pomocą kalendarza.