Continuous Global Positioning System (GPS) observations have been logged at the Finnish Antarctic research station (Aboa) since February 2003. The station is located in Dronning Maud Land, East Antarctica. Almost 5000 daily observation files have been archived based on yearly scientific expeditions. These files have not been fully analysed until now. This study reports for the first time on the consistent and homogeneous data processing and analysis of the 15-year long time series. Daily coordinates are obtained using Precise Point Positioning (PPP) processing based on two approaches. The first approach is based on the Kalman filter and uses the RTKLIB open source library to produce daily solutions by unconventionally running the filter in the forward and backward direction. The second approach uses APPS web service and is based on GIPSY scientific processing engine. The two approaches show an excellent agreement with less than 3 mm rms error horizontally and 6 mm rms error vertically. The derived position time series is analysed in terms of trend, periodicity and noise characteristics. The noise of the time series was found to be power-law noise model with spectral index closer to flicker noise. In addition, several periodic signals were found at 5, 14, 183 and 362 days. Furthermore, most of the horizontal movement was found to be in the North direction at a rate of 11.23 ± 0.09 mm/y, whereas the rate in the East direction was estimated to be 1.46 ± 0.05 mm/y. Lastly, the 15-year long time series revealed a movement upwards at a rate of 0.79 ± 0.35 mm/y. Despite being an unattended station, Aboa provides one of the most continuous and longest GPS time series in Antarctica. Therefore, we believe that this research increases the awareness of local geophysical phenomena in a less reported area of the Antarctic continent.

The Sagaing Fault is a major tectonic structure between the Indian Plate and Sunda Plate. The fault measures 1200 km along north–south and cuts through the centre of Myanmar. Many urban areas lie along the fault. As a result, Myanmar has established a continuous Global Positioning System (cGPS) network across the Sagaing Fault since 2011. The cGPS network consists of eight cGPS stations that form two transects across the fault. The data analysis covers a period of four years from 2011 to 2014. GAMIT, GLOBK, and TRACK software suite packages are used for GPS data processing and analysis. This study consists of two main objectives. The first objective is to analyse the Myanmar cGPS network observations in order to measure the moving rate and direction of movement for each cGPS station using GAMIT/GLOBK software packages. The second objective is to investigate the co-seismic moving rate associated with the earthquake event using TRACK kinematic positioning program. The analysis results indicate that the east side of the Sagaing Fault moves southeastward at the average rate of approximately 32–40 mm/a, whereas the west side of the fault moves northeastward at the rate of about 31–35 mm/a. For co-seismic analysis, two cGPS stations are analysed in connection with the 2012 M6.8 Thabeikkyin earthquake. These stations are located 50–60 km away from the epicentre. The GPS data analysis clearly showed that the station at the east side of the Sagaing Fault immediately moved south by 15.0 cm, whereas the station at the west side of the fault moved north by 3.0 cm. In conclusion, this study demonstrates that the Sagaing Fault's tectonic activities can be monitored by cGPS observations using geodetic processing techniques. We believe that such investigation brings contribution to better understand of the tectonic activities in Myanmar and South East Asia

Accurate positioning is an important issue to enhance the reality and immersion of 3D urban navigation. The most common positioning technology is GPS, but it can't provide a continuous and accurate solution in dense urban canyons and indoor environments due to signal blockage, interference, or jamming, etc. This paper proposes an integrated GPS and multisensor pedestrian positioning system to bridge the gaps of GPS signal outages. It includes an OEM GPS receiver, a MEMS 3-axis accelerometer and a 2-axis digital compass. The positioning algorithm is a loosely coupled integration of GPS and Pedestrian Dead Reckoning sensors via a Kalman filter. Considering the future applications in embedded systems, the paper gives the minimum sampling rate of accelerometers for the step detection algorithm, which is a combination of three approaches: sliding window, peak detection and zero-crossing. Some field tests were conducted to evaluate the system performance.

The market for Global Navigation Satellite System (GNSS) based applications requiring accurate positioning information has been steadily growing over the recent years. As a consequence of technological advances in GNSS technology, single-frequency, navigation-grade receivers capable to provide carrier phase data can be a cost-effective alternative to the high-professional, geodetic-grade receivers. Navigation-grade receivers are mainly attractive as their cost ranges around of few hundred euros. In addition, the carrier phase measurements are the most accurate observables collected from a GNSS system. As a result, the positioning accuracy obtained with navigation-grade receivers can reach levels that may raise interest various communities that use positioning information. The main purpose of this study is to analyze the performance of high-sensitivity carrier phase-based positioning using navigation-grade equipment. A few static tests covering different time intervals and various baselines with different lengths are investigated. In addition, several kinematic tests are also conducted. The obtained positioning solutions and baseline lengths are compared to the corresponding ones derived from observations collected with professional equipment. The test results demonstrate that cm-level accuracy can be achieved with navigation-grade equipment when it can output carrier phase data. This level of accuracy may be attractive to various applications, such as land, marine or aerial surveying, structural monitoring or early warning systems.

On 12 February 2020, the latest four Galileo satellites had completed one full year of space operational service. The satellites were launched on 25 July 2018. The quartet increased the operational capacity of the Galileo constellation to 22 satellites. This study reports on three signal-in-space (SiS) performance indicators - status, availability, and ranging accuracy - from 11 February 2019 to 12 February 2020. In addition, the study looks also at how the on-board satellite clocks have performed. The data analysis shows 100% data validity and signal health status for three our of the four satellites, whereas NAPA (No Accuracy Prediction Available) events accounted for about 2% of the time. In addition, SiS availability was higher than 95% in the first operational year. Furthermore, the 95th percentile of the global average of the instantaneous signal in space error is found to vary between 0.17 to 0.33 m on monthly basis. Lastly, the precise satellite clock biases show high short-term performance with 0.1 ps/s (10 ^-13 s/s) standard deviations during the first operational year. The numerical results indicate a robust performance and high reliability for the youngest Galileo satellites in the constellation. They increase the number of operational satellites in the constellation and thus contribute to the Galileo's increased popularity in the satellite-based positioning and navigation user community.