Satellite Signal Simulator Research Articles

Implementation of PMF and FFT Acquisition Design for B1C Signal Based on ASPeCT

According to the characteristics of BDS B1C signal, there are many sub peaks in the autocorrelation characteristics, which leads to the ambiguity of B1C signal acquisition. In this paper, the characteristics of B1C signal, acquisition strategy and the ambiguity of different acquisition strategies are analyzed. Based on ASPeCT algorithm, PMF and FFT is implemented in FPGA of navigation receiver. The B1C signal is generated by spiren gss9000 satellite signal simulator, and a test scenario is built for the navigation receiver, which proves the effectiveness of B1C signal acquisition.

Atmospheric Correction of Multiple Reflectance using S3

In remote sensing multi-temporal images are used for assorted type of analysis. The image which is taken by satellite or airborne sensors is affected by atmosphere, so the reflected solar radiation of the image is not actual. Image with incorrect reflectance has no means. Such kind of image need to be corrected before usage. Image comprises of list of values, which needs to undergo this correction process. Existing paradigm provides a means to correct a single reflectance value at a time. Thus, for a list of values, this correction process is cumbersome and tedious. This paper presents a paradigm which allows to correct atmospheric correction of satellite signal for single as well as multiple reflectance values using S3 (Satellite Signal Simulator).

Research on Test Method of Satellite Navigation Signal Simulator

The method of the current acceleration range navigation satellite signal simulator detection theoretically analyzed, but in the actual test work, how to set the satellite navigation signal simulator motion scenes and satellite receivers, a smaller level of the RF test signal navigation As well as implementing automated testing, there is a lack of practical and feasible testing methods. This paper simulates the RF signals received by receivers in different dynamic environments in real time, builds a dynamic range test staging, forms a specific test plan, and carries out the validity, practicability and effectiveness of the test verification test method. This test method is simple and reliable. The dynamic range of the satellite navigation signal simulator in the simulation environment can be accurately detected by this method.

Research on the Design Method of the Navigation Message for GLONASS Signal Simulator

Navigation message provides receivers with important information about the satellite ephemeris, satellite work status and time systems. Correct navigation message enables receivers to achieve the rapid positioning, time service and other functions. The generation of navigation data is a key part of the GLONASS signal simulator.This paper studies the software part of GLONASS satellite signal simulator and describes the generating process of navigation message in detail. This paper studies the structure of GLONASS signal simulator, focusing on the design and calculation of important parameters of navigation message. After commercial receivers test the output signal from the satellite signal simulator, analysis results show that the navigation message is reasonable in this design method.

Study on Hardware-in-the-Loop Simulation System for Navigation and Control of UUV

The Unmanned Underwater Vehicle (UUV) is used more and more widely in military and non-military areas. Since UUVs navigation and motion control system is highly complex, a Hardware-In-the-Loop Simulation (HILS) system is designed and implemented to help research and development of its navigation and motion control system. The HILS system is mainly composed of real-time simulation computer, main control compute, GPS/Beidou satellite signal simulator, three-axis turntable, actuator load simulator, water pressure simulator, acceleration simulation unit, visual computer and interface devices. Performance specifications are allocated to each components of the HILS system according to dynamic characteristics of the UUV under complicated disturbances. Proximity between the results of the UUVs HILS and sea trial demonstrates the validity of the HILS system elementarily.

Design of a Reconfigurable Platform for Navigation Signal Simulation

Navigation signal simulator can generate signals consistent with real GNSS (Global Navigation Satellite System) signals, which can be processed by GNSS receivers in the same manner as it processes satellite signals in a real testing environment. The simulator can offer a high-fidelity means of testing GNSS receivers and other related systems. Such tests can be carried out in laboratories due to control of the GNSS constellation and global atmospheric environment by a single device. The navigation signal simulator, which can provide a real-like environment for the research and testing of navigation receivers, has been the key instrument for developing navigation systems and receiving devices, particularly for high-dynamic receivers. Therefore it has increasingly received widespread attentions in military and industrial sectors. With the development of a variety of new navigation systems and signal standards, there is a higher demand for the compatibility and renewal speed of the navigation signal simulators; specifically, it should be multi-mode and reconfigurable in order to realize the flexible design of navigation systems. Although a lot of GNSS simulators have been developed and used, the reconfigurable technologies have not yet appeared in the literature and applied to practices. This means that the existing simulators cannot achieve simulation of multiple GNSS signals by reconfiguration of the software and hardware on the same platform. In this paper, a new reconfigurable platform for navigation signal simulation is proposed and studied, aiming to simulate multi-mode and multi-frequency navigation signals. The performance of the proposed platform is validated from three perspectives: mathematic simulation software, output signals and receiver operation. The result shows that the platform can generate multi-mode and multi-frequency navigation signals through reconfiguration of the software and hardware on the same platform, hence supporting design of a number of navigation systems including Beidou, Global Positioning System (GPS), Russian Global Navigation Satellite System (GLONASS) and European Galileo system. The GNS8000 series navigation satellite signal simulator, designed based on such platform, have been successfully applied to the Beidou navigation satellite systems and widely used in the related fields of research and industries.

Receiver-channel based adaptive blind equalization approach for GPS dynamic multipath mitigation

Aiming at mitigating multipath effect in dynamic global positioning system (GPS) satellite navigation applications, an approach based on channel blind equalization and real-time recursive least square (RLS) algorithm is proposed, which is an application of the wireless communication channel equalization theory to GPS receiver tracking loops. The blind equalization mechanism builds upon the detection of the correlation distortion due to multipath channels; therefore an increase in the number of correlator channels is required compared with conventional GPS receivers. An adaptive estimator based on the real-time RLS algorithm is designed for dynamic estimation of multipath channel response. Then, the code and carrier phase receiver tracking errors are compensated by removing the estimated multipath components from the correlators’ outputs. To demonstrate the capabilities of the proposed approach, this technique is integrated into a GPS software receiver connected to a navigation satellite signal simulator, thus simulations under controlled dynamic multipath scenarios can be carried out. Simulation results show that in a dynamic and fairly severe multipath environment, the proposed approach achieves simultaneously instantaneous accurate multipath channel estimation and significant multipath tracking errors reduction in both code delay and carrier phase.

An Algorithm for Attitude Signal Simulation Based on Visible Satellite Synchronous Scheduling

In view of the frequent and complex changes of GNSS visible satellite constellation in attitude determination system, an improved attitude signal simulation algorithm for high dynamic satellite signal simulator is proposed. Based on Software Radio architecture, elevation calculation in the antenna coordinate system and channel state control logic under the condition of carrier attitude changes are introduced into the algorithm to implement synchronous scheduling of visible satellite constellation and attitude signal simulation. This work guarantees the simulator to run constantly and stably for a long time with the advantages of high precision and low complexity. Compared with synchronous positioning results from the receiver, the simulation results show that not only can the output signals of the simulator accurately reflect the carrier's attitude characteristics, but also no step error is generated and the positioning precision is not influenced when visible satellite constellation changes.

A Methodology for the Evaluation of a GPS Receiver Performance in Telematics Applications

This paper presents a methodology to evaluate the position availability of automotive grade global positioning system (GPS) receivers intended for Telematics applications utilizing a multichannel GPS satellite signal simulator in a controlled laboratory environment. Initially, field testing of two distinct GPS receivers was conducted in an urban canyon environment and a foliage environment to assess each receiver's position availability performance. Test scenarios were then developed on a multichannel GPS satellite signal simulator in order to create controlled and repeatable stimuli to the GPS receivers. The scenarios take into account the actual satellite constellations at the same day, time, and locations of the field data collections. Furthermore, the number of visible satellites and power levels was adjusted in order to stimulate the hardware tracking sensitivity, hardware acquisition sensitivity, dynamic range, and navigation filter design, all of which impact position availability for GPS receivers. Quantitative results demonstrated good correlation between the results obtained using the developed test scenarios and the results from the field testing. The proposed methodology will result in reducing validation cost and time to market for automotive Telematics products

GPS satellite simulator signal estimation based on ANN

Multi-channel Global Positioning System (GPS) satellite signal simulator is used to provide realistic test signals for GPS receivers and navigation systems. In this paper, signals arriving the antenna of GPS receiver are analyzed from the viewpoint of simulator design. The estimation methods are focused of which several signal parameters are difficult to determine directly according to existing experiential models due to various error factors. Based on the theory of Artificial Neural Network (ANN), an approach is proposed to simulate signal propagation delay, carrier phase, power, and other parameters using ANN. The architecture of the hardware-in-the-loop test system is given. The ANN training and validation process is described. Experimental results demonstrate that the ANN designed can statistically simulate sample data in high fidelity. Therefore the computation of signal state based on this ANN can meet the design requirement, and can be directly applied to the development of multi-channel GPS satellite signal simulator.