Attitude Determination using Single Frequency GNSS Receivers for Small UAVs

2015 ◽  
Vol 2015.6 (0) ◽  
pp. 112 ◽  
Author(s):  
Taro Suzuki ◽  
Takeshi Akehi ◽  
Takuma Massubuchi ◽  
Yoshiharu Amano
Keyword(s):  
Attitude Determination ◽  
Single Frequency ◽  
Gnss Receivers

Reducing multipath effect of low-cost GNSS receivers for monitoring by considering temporal correlations

2020 ◽  
Vol 14 (2) ◽  
pp. 167-175
Author(s):  
Li Zhang ◽  
Volker Schwieger
Keyword(s):  
Low Cost ◽  
Ground Plane ◽  
Single Frequency ◽  
Spatial Correlations ◽  
Raw Data ◽  
Multipath Effect ◽  
Temporal Correlations ◽  
Multipath Effects ◽  
Gnss Receivers ◽  
Multipath Signals

AbstractThe investigations on low-cost single frequency GNSS receivers at the Institute of Engineering Geodesy (IIGS) show that u-blox GNSS receivers combined with low-cost antennas and self-constructed L1-optimized choke rings can reach an accuracy which almost meets the requirements of geodetic applications (see Zhang and Schwieger [25]). However, the quality (accuracy and reliability) of low-cost GNSS receiver data should still be improved, particularly in environments with obstructions. The multipath effects are a major error source for the short baselines. The ground plate or the choke ring ground plane can reduce the multipath signals from the horizontal reflector (e. g. ground). However, the shieldings cannot reduce the multipath signals from the vertical reflectors (e. g. walls).Because multipath effects are spatially and temporally correlated, an algorithm is developed for reducing the multipath effect by considering the spatial correlations of the adjoined stations (see Zhang and Schwieger [24]). In this paper, an algorithm based on the temporal correlations will be introduced. The developed algorithm is based on the periodic behavior of the estimated coordinates and not on carrier phase raw data, which is easy to use. Because, for the users, coordinates are more accessible than the raw data. The multipath effect can cause periodic oscillations but the periods change over time. Besides this, the multipath effect’s influence on the coordinates is a mixture of different multipath signals from different satellites and different reflectors. These two properties will be used to reduce the multipath effect. The algorithm runs in two steps and iteratively. Test measurements were carried out in a multipath intensive environment; the accuracies of the measurements are improved by about 50 % and the results can be delivered in near-real-time (in ca. 30 minutes), therefore the algorithm is suitable for structural health monitoring applications.

A remark on the GNSS single difference model with common clock scheme for attitude determination

2016 ◽  
Vol 10 (3) ◽  
Author(s):  
Wantong Chen
Keyword(s):  
Attitude Determination ◽  
Phase Measurement ◽  
Qualitative Assessment ◽  
Actual System ◽  
Carrier Phase Measurement ◽  
Gnss Receivers ◽  
Single Difference ◽  
Important Field ◽  
The Common ◽  
Specific Care

AbstractGNSS-based attitude determination technique is an important field of study, in which two schemes can be used to construct the actual system: the common clock scheme and the non-common clock scheme. Compared with the non-common clock scheme, the common clock scheme can strongly improve both the reliability and the accuracy. However, in order to gain these advantages, specific care must be taken in the implementation. The cares are thus discussed, based on the generating technique of carrier phase measurement in GNSS receivers. A qualitative assessment of potential phase bias contributes is also carried out. Possible technical difficulties are pointed out for the development of single-board multi-antenna GNSS attitude systems with a common clock.

The use of low-cost, single-frequency GNSS receivers in mapping surveys

Survey Review ◽  
2016 ◽  
Vol 50 (358) ◽  
pp. 46-56 ◽  
Author(s):  
M. Tsakiri ◽  
A. Sioulis ◽  
G. Piniotis
Keyword(s):  
Low Cost ◽  
Single Frequency ◽  
Gnss Receivers

scholarly journals Potential of Cost-Efficient Single Frequency GNSS Receivers for Water Vapor Monitoring

2018 ◽  
Vol 10 (9) ◽  
pp. 1493 ◽  
Author(s):  
Andreas Krietemeyer ◽  
Marie-claire ten Veldhuis ◽  
Hans van der Marel ◽  
Eugenio Realini ◽  
Nick van de Giesen
Keyword(s):  
Water Vapor ◽  
Low Cost ◽  
Global Navigation Satellite Systems ◽  
Single Frequency ◽  
Small Scale ◽  
Reference Network ◽  
Tropospheric Delay ◽  
Dual Frequency ◽  
Gnss Receivers ◽  
Cost Efficient

Dual-frequency Global Navigation Satellite Systems (GNSSs) enable the estimation of Zenith Tropospheric Delay (ZTD) which can be converted to Precipitable Water Vapor (PWV). The density of existing GNSS monitoring networks is insufficient to capture small-scale water vapor variations that are especially important for extreme weather forecasting. A densification with geodetic-grade dual-frequency receivers is not economically feasible. Cost-efficient single-frequency receivers offer a possible alternative. This paper studies the feasibility of using low-cost receivers to increase the density of GNSS networks for retrieval of PWV. We processed one year of GNSS data from an IGS station and two co-located single-frequency stations. Additionally, in another experiment, the Radio Frequency (RF) signal from a geodetic-grade dual-frequency antenna was split to a geodetic receiver and two low-cost receivers. To process the single-frequency observations in Precise Point Positioning (PPP) mode, we apply the Satellite-specific Epoch-differenced Ionospheric Delay (SEID) model using two different reference network configurations of 50–80 km and 200–300 km mean station distances, respectively. Our research setup can distinguish between the antenna, ionospheric interpolation, and software-related impacts on the quality of PWV retrievals. The study shows that single-frequency GNSS receivers can achieve a quality similar to that of geodetic receivers in terms of RMSE for ZTD estimations. We demonstrate that modeling of the ionosphere and the antenna type are the main sources influencing the ZTD precision.

scholarly journals An Improved Single-Epoch Attitude Determination Method for Low-Cost Single-Frequency GNSS Receivers

2021 ◽  
Vol 13 (14) ◽  
pp. 2746
Author(s):  
Xinzhe Wang ◽  
Yinbin Yao ◽  
Chaoqian Xu ◽  
Yinzhi Zhao ◽  
Huan Zhang
Keyword(s):  
Degrees Of Freedom ◽  
High Efficiency ◽  
Attitude Determination ◽  
Search Algorithm ◽  
Low Cost ◽  
Single Frequency ◽  
Baseline Length ◽  
Short Baseline ◽  
Cycle Slips ◽  
Ambiguity Fixing

GNSS attitude determination has been widely used in various navigation and positioning applications, due to its advantages of low cost and high efficiency. The navigation positioning and attitude determination modules in the consumer market mostly use low-cost receivers and face many problems such as large multipath effects, frequent cycle slips and even loss of locks. Ambiguity fixing is the key to GNSS attitude determination and will face more challenges in the complex urban environment. Based on the CLAMBDA algorithm, this paper proposes a CLAMBDA-search algorithm based on the multi-baseline GNSS model. This algorithm improves the existing CLAMBDA method through a fixed geometry constraint among baselines in the vehicle coordinate system. A fixed single-baseline solution reduces two degrees of freedom of vehicle rigid body, and a global minimization search for the ambiguity objective function in the other degree of freedom is conducted to calculate the baseline vector and its Euler angles. In addition, in order to make up for the shortcomings of short baseline ambiguity in complex environments, this paper proposes different validation strategies. Using three low-cost receivers (ublox M8T) and patch antennas, static and dynamic on-board experiments with different baseline length set-ups were carried out in different environments. Both the experiments prove that the method proposed in this paper has greatly improved the ambiguity fixing performance and also the Euler angle calculation accuracy, with an acceptable calculation burden. It is a practical vehicle-mounted attitude determination algorithm.

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