Satellite Navigation Equipment Research Articles

Method for monitoring and improving the accuracy characteristics of shipboard satellite navigation equipment

The aim of the study is to improve approaches to monitoring and control of electronic systems of water transport, as well as navigation support itself, to improve navigation safety by developing a method for monitoring and improving the accuracy characteristics of shipboard satellite navigation equipment in real operating conditions. The article considers the importance of modern ship radio navigation systems for ensuring safety of navigation and highlights the limitations that may arise during operation of these systems. In this regard, the authors of the article propose an approach to monitoring and improving the accuracy of satellite navigation equipment of a ship in real conditions of ship operation. The article considers the use of a ground-based control and measurement station to control the precise characteristics of shipboard satellite navigation equipment. This station is installed on shore and operates based on the basic equation of metrology. The positioning system of a laser locator ship is described as follows: The GPS navigation spacecraft sends a laser beam to an optical angle reflector mounted on the vessel, and then a ground-based control and measurement station measures the time it takes for the laser beam to travel to and from the reflector, which allows the distance to the vessel to be calculated. The data is then transmitted to user equipment on the ship, which uses it in conjunction with the spacecraft's GPS navigation data to determine the ship's location, time and speed. The features of this approach are its high accuracy and applicability in various conditions, including poor visibility. To consider the geometric differences between the antennas of the ground control and measuring station and the user's equipment, as well as to consider the roll and pitch, the authors propose to use geometric ratios. The use of the method of accuracy control of shipboard satellite navigation equipment based on a ground-based control and measuring station proposed in the article allows to determine errors with high accuracy in various conditions of real operation, which contributes to the improvement of navigation safety

ОБЗОР И АНАЛИЗ МЕТОДОВ ОБСЛЕДОВАНИЯ ДОРОЖНОГО ДВИЖЕНИЯ, ИСПОЛЬЗУЮЩИХ СОВРЕМЕННЫЕ ИНФОРМАЦИОННЫЕ, ТЕХНОЛОГИЧЕСКИЕ И ПРОГРАММНЫЕ РЕШЕНИЯ ДЛЯ РЕГИСТРАЦИИ ЗНАЧЕНИЙ ОСНОВНЫХ ПАРАМЕТРОВ, ХАРАКТЕРИЗУЮЩИХ ДОРОЖНОЕ ДВИЖЕНИЕ

This article presents an overview and analysis of modern methods and tools for assessing the parameters and effectiveness of traffic management in cities. The possibilities of using satellite navigation equipment to assess the quality of traffic management are considered, as well as the possibilities of using geoinformation systems, transport detectors, software for "streaming" video content processing are presented

Actuators and Sensors for Application in Agricultural Robots: A Review

In recent years, with the rapid development of science and technology, agricultural robots have gradually begun to replace humans, to complete various agricultural operations, changing traditional agricultural production methods. Not only is the labor input reduced, but also the production efficiency can be improved, which invariably contributes to the development of smart agriculture. This paper reviews the core technologies used for agricultural robots in non-structural environments. In addition, we review the technological progress of drive systems, control strategies, end-effectors, robotic arms, environmental perception, and other related systems. This research shows that in a non-structured agricultural environment, using cameras and light detection and ranging (LiDAR), as well as ultrasonic and satellite navigation equipment, and by integrating sensing, transmission, control, and operation, different types of actuators can be innovatively designed and developed to drive the advance of agricultural robots, to meet the delicate and complex requirements of agricultural products as operational objects, such that better productivity and standardization of agriculture can be achieved. In summary, agricultural production is developing toward a data-driven, standardized, and unmanned approach, with smart agriculture supported by actuator-driven-based agricultural robots. This paper concludes with a summary of the main existing technologies and challenges in the development of actuators for applications in agricultural robots, and the outlook regarding the primary development directions of agricultural robots in the near future.

Spacecraft rendezvous and docking using measurements from satellite navigation equipment combined with the optical subsystem for final approach

The paper discusses an integrated system for spacecraft rendezvous and docking using measurements from satellite navigation equipment combined with the optical final approach subsystem (OFAS) which generates high-precision relative position vector during final approach It addresses issues involved in designing an OFAS which has to operate in an environment exposed to sunlight and provides an estimate for the accuracy of the relative position measurements depending on the current range and OFAS configuration. Simulations have been run of the final approach involving simultaneous control for m the satellite navigation equipment and OFAS. It was shown that at the moment of initial contact the approach accuracy of 2–5 cm for relative position, and of 1 cm/s for velocity is achieved. Key words: spacecraft, navigation, rendezvous, docking, final approach, satellite navigation, optical sensor, TV camera, control, precision.

Spacecraft rendezvous and docking using measurements from satellite navigation equipment combined with the optical subsystem for final approach

The paper discusses an integrated system for spacecraft rendezvous docking using measurements from satellite navigation equipment combined and with the optical final approach subsystem (OFAS) which generates high-precision relative 2Space Research Institute of the Russian Academy of Sciences (SRI RAS) 84/32 Profsoyuznaya str., Moscow, 117997, Russian Federation, e-mail: iki@cosmos.ru position vector during final approach. It addresses issues involved in designing an an on OFAS which has to operate in an environment exposed to sunlight and provides estimate for the accuracy of the relative position measurements depending the current range and OFAS configuration. Simulations have been run of the final approach involving simultaneous control from the satellite navigation equipment and OFAS. It was shown that at the moment of initial contact the approach accuracy of 2–5 cm for relative position, and of 1 cm/s for velocity is achieved.

Исследование точности определения пространственных координат из обработки изображений с беспилотного воздушного судна

The authors present the results of numerical experiments aimed to determine the mean square error, which can be used to obtain the spatial coordinates of the object’s under study points through processing images obtained from UAVs using only on-Board global satellite and inertial navigation equipment on drones. At those experiments, aerial photography from the UAVs was modeled for mapping and solving the engineering task of creating a three-dimensional building (structure) model. A pair of images was simulated for the research. The results using the characteristics of the GNSS inertial solutions Trimble АРХ-15 UAV and Trimble АРХ-20 UAV are presented. The experiments show that at solving engineering tasks under conditions corresponding to an arbitrary case of aerial photography, in order to determinie the spatial coordinates with the mean square error not more than 15 mm, the same error of determining the linear elements of external orientation should be 2–5 mm, and the angular elements 10–20ʺ. This significantly exceeds the characteristics corresponding to the post-processing mode for the specified GNSS-inertial solutions. The authors show the effect of angular elements’ external orientation errors to resulting the mean square error of each coordinate and a possible approach to reducing it.

Мониторинг литорали с применением беспилотного летательного аппарата

The authors explore the littoral as a natural phenomenon using geodetic methods. Littoral is an areal object and is closely related to coastal abrasion. The abrasion destroys the coastal zone. Preventing the destruction of the coastal zone requires monitoring the littoral, forming its model and that of littoral dynamics. Littoral and dynamo models enable developing recommendations for protecting the coastal zone. Having remote sensing data only we are unable to perform littoral monitoring efficiently. It does not ensure the accuracy and relevance of the state of the coastal zone. The monitoring task can only be solved with the use of integrated geodetic support.This support includes geodetic work and the use of an unmanned aerial vehicle for monitoring the littoral. The authors explore littoral as a natural phenomenon. A new method of obtaining spatial coordinates using images obtained from UAVs is described. The essence of the methodology is determining spatial coordinates using single images. The technology includes the use of water level sensors to define the exact height of the survey. The methodology involves the use of satellite navigation equipment to determine the coordinates of the camera at the time of shooting. Special here is that the littoral boundary is a fuzzy object calculated on the basis of statistical data. The research shows that the geodetic technologies are the basis of the integrated one. The authors providethe analysis of the situation and suggest measures for monitoring the coastline.

Development of a methodological approach and software for information processing and experimental assessment of the accuracy of the “Sazhen-TA” measuring system

This paper presents algorithms for determining trajectory parameters using the information provided by the “Sazhen-TA” system. Issues associated with experimental assessment of the accuracy of the “Sazhen-TA” measuring system on the basis of reference data from satellite navigation equipment are considered. The results of mathematical modelling are presented.

Anti-jamming antenna array model for satellite navigation equipment

The paper introduces the brief results of modeling an antenna array designed to be used as part of anti-jamming satellite navigation equipment. The study describes the procedure for calculating the weight coefficients of the antenna array based on the orthogonalization of signal and jamming spaces. According to the weight coefficients found, the resultant antenna patterns are plotted. Findings of the research show the results of how the depth of sample accumulation influences the effectiveness of adaptation to the jamming environment

Phase drift on networks of coupled crystal oscillators for precision timing.

Precise time dissemination and synchronization have been some of the most important technological tasks for several centuries. Since the early 1800s, it was realized that precise time-keeping devices having the same stable frequency and precisely synchronized can have important applications in navigation. In modern times, satellite-based global positioning and navigation systems such as the GPS use the same principle. However, even the most sophisticated satellite navigation equipment cannot operate in every environment. In response to this need, we present a computational and analytical study of a network-based model of a high-precision, inexpensive, coupled crystal oscillator system and timing (CCOST) device. A bifurcation analysis (carried out by the authors in a related publication) [Buono et al., SIAM J. Appl. Dyn. Syst. 17, 1310 (2018)1536-004010.1137/16M1066154] of the network dynamics shows a wide variety of collective patterns, mainly various forms of discrete rotating waves and synchronization patterns. Results from computer simulations seem to indicate that, among all patterns, the standard traveling wave pattern in which consecutive crystals oscillate out of phase by 2π/N, where N is the network size, leads to phase drift error that decreases as 1/N as opposed to 1/sqrt[N] for an uncoupled ensemble. The results should provide guidelines for future experiments, design, and fabrication tasks.

High-precision frequency measurement system based on different frequency quantization phase comparison

Aiming at the requirements of phase comparison without frequency normalization, a high-precision frequency measurement system is proposed based on different frequency quantization phase comparison. Using group phase difference pulse in the least common multiple period, the period of frequency standard signal, the period of the measured signal and the pulse width of group phase difference can be respectively counted with the aid of FPGA technology. The obtained counter value is saved and sent to host computer. The measured frequency can be obtained by the data processing of the host computer. Experimental results show that the short-term frequency stability of the system better than E−12/s is achieved. Compared to the traditional frequency measurement system, the system have the advantages of wide measurement range, high frequency stability, low phase noise and low development cost. The system not only plays an important role in precise measurement physics fields such as high-precision transmission and comparison of time and frequency, measurement and suppression of phase noise, but also has a wider application in localization of spatial motion radiation source, satellite navigation equipment, precise time frequency measurement, communication, radar and other high-tech fields.

On the rapid orbital attitude control of manned and cargo spacecraft Soyuz MS and Progress MS

An algorithm for the rapid construction of the orbital coordinate system (OCS) used in the control system of the manned and cargo spacecraft Soyuz MS and Progress MS is considered. The algorithm is used to speed up the current determination of the state vector value using the satellite navigation equipment immediately after the spacecraft is placed into the Earth’s artificial satellite orbit and the launch vehicle is separated. The proposed algorithm is based on an a priori knowledge of the launch vehicle’s attitude parameters at the time of separation and on the angular velocity (AV) measurements available on board after the start of the strapdown inertial navigation system (SINS). The efficiency of the rapid orbital attitude control algorithm is confirmed by the results of the mathematical modeling and flight development tests.

Radar Target Modeling Using In-Flight Radar Cross-Section Measurements

A flight experiment with the Saab 105 aircraft and the radar cross-section measurement system Arken has been performed at C and Ku bands. Two types of trajectories were flown, and the flight state was recorded using inertial and satellite navigation equipment. The data were used to recreate the flight in a simulator where the aspect angles and range to the measurement system could be calculated. The measured radar cross section as a function of time was presented and compared to various statistical fluctuation models, including the distributions used in Swerling cases. Findings showed that the generalized Pareto distribution fit the measured data best and that Swerling case 2 was a good candidate for describing the dynamics of the radar cross section at the Ku band when the aircraft approached the radar head-on. The measured radar cross-section data were analyzed using the fast Fourier transform, from which fluctuation rates for different carrier frequencies and trajectories could be estimated.

Implementation of Satellite Techniques in the Air Transport

Abstract The article shows process of the implementation satellite systems in Polish aviation which contributed to accomplishment Performance-Based Navigation (PBN) concept. Since 1991 authors have introduced Satellite Navigation Equipment in Polish Air Forces. The studies and researches provide to the Polish Air Force alternative approaches, modernize their navigation and landing systems and achieve compatibility with systems of the North Atlantic Treaty Organization (NATO) and International Civil Aviation Organization (ICAO). Acquired experience, conducted military tests and obtained results enabled to take up work scientifically - research in the environment of the civil aviation. Therefore in 2008 there has been launched cooperation with Polish Air Navigation Services Agency (PANSA). Thanks to cooperation, there have been compiled and fulfilled three fundamental international projects: EGNOS APV MIELEC (EGNOS Introduction in European Eastern Region - APV Mielec), HEDGE (Helicopters Deploy GNSS in Europe), SHERPA (Support ad-Hoc to Eastern Region Pre-operational in GNSS). The successful completion of these projects enabled implementation 21 procedures of the RNAV GNSS final approach at Polish airports, contributing to the implementation of PBN in Poland as well as ICAO resolution A37-11. Results of conducted research which served for the implementation of satellite techniques in the air transport constitute the meaning of this material.

Using GLONASS for precise determination of navigation parameters under interference from various sources*

This article discusses the main approaches to the designs of systems for determining location and spatial attitude based on satellite navigation equipment. The article describes possible solutions for constructing an angular attitude measurement system capable of spatial interference selection on the basis of a single antenna system.

Satellite Network Design Approach to Orbit Determination for GNSS

This research work gives the brief knowledge of the orbit determination for Global Navigation Satellite System (GNSS), which described the result of some techniques for orbit determination. In this we have also discussed that how we can design a network for orbit determination of GNSS. The main approach that need to be solved by researchers to monitor the data processing and developing procedures for digital signal processing in micro and onboard satellite navigation equipment have been described. In this paper discussed that how we transfer the data information through the satellite laser link and satellite radio frequency links. After that we analyze that how the data can be transfer between two satellites by considering the epidemic model.

Determination of trajectory parameters for a small satellite using raw satellite measurements

The problem of determining the trajectory parameters of a small satellite using a satellite navigation equipment is studied. A raw data processing algorithm is proposed when the measurements from a global navigation satellite system are not always regular.

Education

``We are on line of position 157-337. Will repeat this message on 6210 kilocycles. We are running north and south.” --Amelia Earhart on 2 July 1937 in her last transmission to Coast Guard cutter Itasca This was the last verified transmission from Amelia Earhart and her navigator Fred Noonan as they were crossing over the Pacific Ocean from Lae to Howland Island in an attempt to fly around the world along an equatorial route. Their disappearance, despite the most exhaustive maritime search in history, made them two of the most famous missing people in the world. Arguably, had their wreckage been rapidly discovered, the artifacts would have led to a clear understanding of what happened to them, and their loss would be much less notable in aviation history. Then and now, we accept failure as long as we learn from it. It never sits well with the public when the best technology, sound reasoning, and concerted effort fails to answer questions like, “Where are they?'' and “What happened to them?” Almost eighty years later, we are considerably more advanced. Long distance commercial airline travel is incredibly safe. Crew members can communicate with an air traffic control facility at any time. Using sophisticated satellite, inertial, radar, and VHF navigation equipment, airline crew and ground stations can determine an aircraft's precise position relatively easily. In fact, commercial aircraft have features which automatically communicate with ground stations at regular intervals. And yet in March of 2014, a state-of-the-art commercial jetliner carrying 239 souls disappeared over the Pacific, and once again, despite the best efforts of several nations, the crash site has yet to be discovered. Similar to the disappearance of Amelia Earhart almost 80 years ago, determining the most likely trajectory and final position is a complex mathematical problem. This Education section features a self-contained module by John Zweck that walks through the mathematics underlying the search for the crash site of MH370. Since MH370 flew for more than six hours after the last known communication between the pilot and air traffic control, the primary evidence in the search is the pings from the automated Aircraft Communications Addressing and Reporting System. Since these pings travel to a satellite and then to a ground station, analysis of ping travel time and Doppler shift provides some information about the aircraft position and speed. The article contains a very understandable derivation that maps the aircraft trajectory on a sphere and satellite positions to ping duration and Doppler shift. Each model for the aircraft's trajectory needs to be reconciled with actual data to determine model parameters, ultimately leading to a classic optimization problem. Using the ideas in this article together with official data from MH370, one can compute something very close to the priority search area used by the Australian Transportation Safety Board, the organization that is coordinating the underwater search. In the time since this article was received, wreckage from MH370 has washed ashore on Réunion Island and later other scattered locations, consistent with Lagrangian trajectories from the priority search area. The underwater search still continues and hopefully will be more successful than the search for Earhart's missing Lockheed Electra 10E, bringing closure to the families of the victims and to a public that still wonders what happened. This article is self-contained and appropriate for an advanced undergraduate course or a project. One interesting feature of the official inquiry into the MH370 disappearance is that the investigation team publicly released the data and their reasoning. This allowed many groups to explore the data and verify the official determination of the most likely trajectory. In addition to the scientific and public relations benefits to this approach, the release of the data had the unforeseen benefit of allowing exciting problems like these to quickly enter the classroom and inspire students with compelling problems.

O возможности построения бесплатформенных систем управления ракет-носителей с использованием аппаратуры спутниковой навигации GPS

O возможности построения бесплатформенных систем управления ракет-носителей с использованием аппаратуры спутниковой навигации GPS

Phase methods for measuring the spatial orientation of objects using satellite navigation equipment

This paper discusses phase methods for measuring the spatial orientation of objects using satellite navigation equipment. An analysis of methods for resolving phase ambiguity is presented in the paper. The effectiveness and applicability of the single-step methods are discussed in detail. The authors have shown that applying the exhaustive method requires a constellation of 5 - 6 visible satellites. The measurement of signals, having a base length of 1 m transmitted from 8 satellites, demonstrates that an unambiguous solution is achieved practically in all cases.