scholarly journals A New Era in Spatial Data Recording: Low-Cost GNSS

2019 ◽  
Vol 7 (2) ◽  
pp. 169-177 ◽  
Author(s):  
Austin Chad Hill ◽  
Fred Limp ◽  
Jesse Casana ◽  
Elise Jakoby Laugier ◽  
Malcolm Williamson
Keyword(s):  
Spatial Data ◽  
Low Cost ◽  
Three Dimensional ◽  
Global Navigation Satellite Systems ◽  
New Era ◽  
Satellite Systems ◽  
Small Areas ◽  
Rtk Gps ◽  
Global Navigation Satellite ◽  
The Cost

AbstractArchaeologists have long recognized that precise three-dimensional coordinates are critical for recording objects and features across sites and landscapes. Traditionally, for relatively small areas, an optical transit or, more recently, an electronic distance measurement device (EDM) has been used to acquire these three-dimensional points. While effective, such systems have significant limitations in that they require a clear line of site. Real-time kinematic (RTK) GPS/GNSS systems (Global Positioning System/Global Navigation Satellite Systems) have been available for well over a decade, and can provide quick and accurate point measurements over a wide area without many of the limitation of older technologies. The cost of such systems, however, has generally been prohibitive for archaeologists, and so their use has been rare. Recently, a new generation of low-cost systems has become available, making this technology more accessible to a wider user base. This article describes the use, accuracy, and limitations of one such low-cost system, the Emlid Reach RS, to show why this is an important tool for archaeological fieldwork.

scholarly journals Centimeter-Level Recording for All: Field Experimentation with New, Affordable Geolocation Technology

2019 ◽  
Vol 7 (4) ◽  
pp. 353-365 ◽  
Author(s):  
Peter J. Cobb ◽  
Tiffany Earley-Spadoni ◽  
Philip Dames
Keyword(s):  
Spatial Data ◽  
Field Data ◽  
Low Cost ◽  
Field Application ◽  
Global Navigation Satellite Systems ◽  
Precise Location ◽  
Satellite Systems ◽  
Surface Survey ◽  
Field Experimentation ◽  
Global Navigation Satellite

AbstractThe methodical recording and representation of spatial data are central to archaeological fieldwork and research. Until recently, centimeter-level precise geolocation equipment was the exclusive domain of researchers who could afford setups costing tens of thousands of dollars. However, high-quality measurements are being made more accessible by rapidly evolving technologies. These new tools, when used together with mobile technology for efficiently recording field data, open up the possibility of capturing the precise location of every find during an archaeological surface survey. An important step in reaching the desired outcome—centimeter-level recording for all—is experimentation with a variety of emerging low-cost setups. Accordingly, we tested the Reach and Reach RS, differential global navigation satellite systems (dGNSS) equipment produced by the company Emlid, during a surface survey in Armenia in June 2018. Our field application demonstrates that the use of dGNSS is already possible and that the described advances in precision enable improved recording and representation of spatial data.

scholarly journals UAVS ENHANCED NAVIGATION IN OUTDOOR GNSS DENIED ENVIRONMENT USING UWB AND MONOCULAR CAMERA SYSTEMS

2019 ◽  
Vol XLII-2/W13 ◽  
pp. 665-672 ◽  
Author(s):  
S. Zahran ◽  
A. Masiero ◽  
M. M. Mostafa ◽  
A. M. Moussa ◽  
A. Vettore ◽  
...  
Keyword(s):  
Navigation System ◽  
Low Cost ◽  
Global Navigation Satellite Systems ◽  
Ultra Wideband ◽  
Measurement Unit ◽  
Satellite Systems ◽  
Monocular Camera ◽  
Camera Systems ◽  
Global Navigation Satellite ◽  
The Cost

<p><strong>Abstract.</strong> The demand for small Unmanned Aerial Vehicles (UAVs) is massively increasing these days, due to the wide variety of applications utilizing such vehicles to perform tasks that may be dangerous or just to save time, effort, or cost. Small UAVs navigation system mainly depends on the integration between Global Navigation Satellite Systems (GNSS) and Inertial Measurement Unit (INS) to estimate the Positions, Velocities, and Attitudes (PVT) of the vehicle. Without GNSS such UAVs cannot navigate for long periods of time depending on INS alone, as the low-cost INS typically exhibits massive accumulation of errors during GNSS absence. Given the importance of ensuring full operability of the UAVs even during GNSS signals unavailability, other sensors must be used to bound the INS errors and enhance the navigation system performance. This paper proposes an enhanced UAV navigation system based on integration between monocular camera, Ultra-Wideband (UWB) system, and INS. In addition to using variable EKF weighting scheme. The paper also investigates this integration in the case of low density of UWB anchors, to reduce the cost required for such UWB system infrastructure. A GoPro Camera and UWB rover were attached to the belly of a quadcopter, an on the shelf commercial drone (3DR Solo), during the experimental flight. The velocity of the vehicle is estimated with Optical Flow (OF) from camera successive images, while the range measurements between the UWB rover and the stationary UWB anchors, which were distributed on the field, were used to estimate UAV position.</p>

scholarly journals Adjustment of an Integrated Geodetic Network Composed of GNSS Vectors and Classical Terrestrial Linear Pseudo-Observations

2021 ◽  
Vol 11 (10) ◽  
pp. 4352
Author(s):  
Tadeusz Gargula
Keyword(s):  
Three Dimensional ◽  
Geodetic Network ◽  
Global Navigation Satellite Systems ◽  
Adjustment Process ◽  
Dimensional System ◽  
Integrated Network ◽  
Satellite Systems ◽  
Linear Distance ◽  
Easy Integration ◽  
Global Navigation Satellite

The paper proposes a new method for adjusting classical terrestrial observations (total station) together with satellite (GNSS-Global Navigation Satellite Systems) vectors. All the observations are adjusted in a single common three-dimensional system of reference. The proposed method does not require the observations to be projected onto an ellipsoid or converted between reference systems. The adjustment process follows the transformation of a classical geodetic network (distances and horizontal and vertical angles) into a spatial linear (distance) network. This step facilitates easy integration with GNSS vectors when results are numerically processed. The paper offers detailed formulas for calculating pseudo-observations (spatial distances) from input terrestrial observations (horizontal and vertical angles, horizontal distances, height of instrument and height of target). The next stage was to set observation equations and transform them into a linear form (functional adjustment model of geodetic observations). A method was provided as well for determining the mean errors of the pseudo-observations, necessary to assess the accuracy of the values following the adjustment (point coordinates). The proposed algorithm was verified in practice whereby an integrated network made up of a GNSS vector network and a classical linear-angular network was adjusted.

scholarly journals A Surface KInematics Buoy (SKIB) for wave-current interactions studies

2018 ◽  
Author(s):  
Pedro Veras Guimarães ◽  
Fabrice Ardhuin ◽  
Peter Sutherland ◽  
Mickael Accensi ◽  
Michel Hamon ◽  
...  
Keyword(s):  
Low Cost ◽  
Short Wave ◽  
Global Navigation Satellite Systems ◽  
Motion Sensor ◽  
Satellite Systems ◽  
Ocean Surface Waves ◽  
Sensing Applications ◽  
Hull Design ◽  
Sensor Package ◽  
Global Navigation Satellite

Abstract. Global Navigation Satellite Systems (GNSS) and modern motion-sensor packages allow the measurement of ocean surface waves with low-cost drifters. Drifting along or across current gradients provides unique measurements of wave-current interactions. In this study, we investigate the response of several combinations of GNSS receiver, motion-sensor package and hull design in order to define a prototype surface kinematic buoy (SKIB) that is particularly optimized for measuring wave-current interactions, including relatively short wave components (relative frequency around 1 Hz) that are important for air-sea interactions and remote sensing applications. The comparison with existing Datawell Directional Waverider and SWIFT buoys, as well as stereo-video imagery demonstrates the accuracy of SKIB. The use of low-cost accelerometers and a spherical ribbed and skirted hull design provide acceptable heave spectra, while velocity estimates from GNSS receivers yield a mean direction and directional spread. Using a low-power acquisition board allows autonomous deployments over several months with data transmitted by satellite. The capability to measure current-induced wave variations is illustrated with data acquired in a macro-tidal coastal environment.

scholarly journals Low cost GNSS receivers in time synchronization systems

2018 ◽  
Vol 67 (1) ◽  
pp. 65-72
Author(s):  
Grzegorz Czopik ◽  
Tomasz Kraszewski
Keyword(s):  
Time Synchronization ◽  
Low Cost ◽  
Global Navigation Satellite Systems ◽  
Satellite Systems ◽  
Time Frequency ◽  
Delay Times ◽  
Gnss Receivers ◽  
Frequency Counter ◽  
The One ◽  
Global Navigation Satellite

The GNSS (GNSS — Global Navigation Satellite Systems) receivers can be utilized to obtain accurate time markers. The preliminary results of the cheap GNSS receivers’ tests are presented in the paper. The one receiver’s price (including antenna) does not exceed 30 $. The studies on the use of receivers in the time synchronization systems were executed. Three identical models of receiver modules were used. The 1PPS (1PPS — 1 Pulse Per Second) signals available on the receiver’s output were used. The 1PPS’s main time characteristics were described. Delay times between different receivers 1PPS signals were measured. Measurements were taken using 1 GHz oscilloscope and precise time/frequency counter T3200U. Keywords: time synchronization, 1PPS, GNSS, GPS time

scholarly journals Robust Estimators in Geodetic Networks Based on a New Metaheuristic: Independent Vortices Search

Sensors ◽  
2019 ◽  
Vol 19 (20) ◽  
pp. 4535 ◽  
Author(s):  
Ismael Érique Koch ◽  
Ivandro Klein ◽  
Luiz Gonzaga ◽  
Marcelo Tomio Matsuoka ◽  
Vinicius Francisco Rofatto ◽  
...  
Keyword(s):  
Large Scale ◽  
Three Dimensional ◽  
Search Space ◽  
Global Navigation Satellite Systems ◽  
Robust Estimator ◽  
Satellite Systems ◽  
Original Algorithm ◽  
Geodetic Networks ◽  
Global Navigation Satellite ◽  
Better Than

Geodetic networks provide accurate three-dimensional control points for mapping activities, geoinformation, and infrastructure works. Accurate computation and adjustment are necessary, as all data collection is vulnerable to outliers. Applying a Least Squares (LS) process can lead to inaccuracy over many points in such conditions. Robust Estimator (RE) methods are less sensitive to outliers and provide an alternative to conventional LS. To solve the RE functions, we propose a new metaheuristic (MH), based on the Vortex Search (IVS) algorithm, along with a novel search space definition scheme. Numerous scenarios for a Global Navigation Satellite Systems (GNSS)-based network are generated to compare and analyze the behavior of several known REs. A classic iterative RE and an LS process are also tested for comparison. We analyze the median and trim position of several estimators, in order to verify their impact on the estimates. The tests show that IVS performs better than the original algorithm; therefore, we adopted it in all subsequent RE computations. Regarding network adjustments, outcomes in the parameter estimation show that REs achieve better results in large-scale outliers’ scenarios. For detection, both LS and REs identify most outliers in schemes with large outliers.

scholarly journals Enhanced Drone Navigation in GNSS Denied Environment Using VDM and Hall Effect Sensor

2019 ◽  
Vol 8 (4) ◽  
pp. 169 ◽  
Author(s):  
Shady Zahran ◽  
Adel Moussa ◽  
Naser El-Sheimy
Keyword(s):  
Hall Effect ◽  
Low Cost ◽  
Integrated System ◽  
Global Navigation Satellite Systems ◽  
Satellite Systems ◽  
Hall Effect Sensor ◽  
Aerial Vehicle ◽  
Heading Estimation ◽  
Global Navigation Satellite ◽  
Vehicle Dynamic Model

The last decade has witnessed a wide spread of small drones in many civil and military applications. With the massive advancement in the manufacture of small and lightweight Inertial Navigation System (INS), navigation in challenging environments became feasible. Navigation of these small drones mainly depends on the integration of Global Navigation Satellite Systems (GNSS) and INS. However, the navigation performance of these small drones deteriorates quickly when the GNSS signals are lost, due to accumulated errors of the low-cost INS that is typically used in these drones. During GNSS signal outages, another aiding sensor is required to bound the drift exhibited by the INS. Before adding any additional sensor on-board the drones, there are some limitations that must be taken into considerations. These limitations include limited availability of power, space, weight, and size. This paper presents a novel unconventional method, to enhance the navigation of autonomous drones in GNSS denied environment, through a new utilization of hall effect sensor to act as flying odometer “Air-Odo” and vehicle dynamic model (VDM) for heading estimation. The proposed approach enhances the navigational solution by estimating the unmanned aerial vehicle (UAV) velocity, and heading and fusing these measurements in the Extended Kalman Filter (EKF) of the integrated system.

GNSS Guidance for All Phases of Flight: Practical Results

2001 ◽  
Vol 54 (1) ◽  
pp. 1-13
Author(s):  
S. J. Leighton ◽  
A. E. McGregor ◽  
D. Lowe ◽  
A. Wolfe ◽  
A. A. Macaulay
Keyword(s):  
Service Providers ◽  
Low Cost ◽  
Air Traffic ◽  
Global Navigation Satellite Systems ◽  
European Symposium ◽  
Navigation Satellite ◽  
Satellite Systems ◽  
The Third ◽  
Potential Benefits ◽  
Global Navigation Satellite

This, and the following three papers, were first presented at GNSS 2000, the Third European Symposium on Global Navigation Satellite Systems held in Edinburgh, Scotland from 1st to 4th May 2000.GNSS, or more specifically, Satellite Based Augmentation System (SBAS), guidance provides the prospect of a low-cost means for aircraft to become equipped to fly area navigation (RNAV) operations. The implementation of such RNAV operations within UK airspace offers potential benefits to both the airline operators and the Air Traffic Service Providers (ATSPs).

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