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Efficiency of using GNSS-PPP for digital elevation model (DEM) production

Abdallah Ashraf, Saifeldin Amgad, Abomariam Abdelhamid, Ali Reda

Artificial Satellites : Journal of Planetary Geodesy

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2020

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Vol. 55, No. 1

17--28

EN

In the developing countries, cost-effective observation techniques are very important for earthwork estimation, map production, geographic information systems, and hydrographic surveying. One of the most cost-effective techniques is Precise Point Positioning (PPP); it is a Global Navigation Satellite Systems (GNSS) positioning technique to compute precise positions using only a single GNSS receiver. This study aims to evaluate the efficiency of using Global Positioning System (GPS) and GPS/ Globalnaya Navigatsionnaya Sputnikovaya Sistema (GLONASS) post-processed kinematic PPP solution for digital elevation model (DEM) production, which is used in earthwork estimation. For this purpose, a kinematic trajectory has been observed in New Aswan City in an open sky area using dual-frequency GNSS receivers. The results showed that, in case of using GPS/GLONASS PPP solution to estimate volumes, the error in earthwork volume estimation varies between 0.07% and 0.16% according to gridding level. On the other hand, the error in volume estimation from GPS PPP solution varies between 0.40% and 0.99%.

2

Kinematic-PPP using single/dual frequency observations from (GPS, GLONASS and GPS/GLONASS) constellations for hydrography

Farah Ashraf

Artificial Satellites : Journal of Planetary Geodesy

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2018

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Vol. 53, No. 1

37--46

EN

Global Positioning System (GPS) technology is ideally suited for inshore and offshore positioning because of its high accuracy and the short observation time required for a position fix. Precise point positioning (PPP) is a technique used for position computation with a high accuracy using a single GNSS receiver. It relies on highly accurate satellite position and clock data that can be acquired from different sources such as the International GNSS Service (IGS). PPP precision varies based on positioning technique (static or kinematic), observations type (single or dual frequency) and the duration of observations among other factors. PPP offers comparable accuracy to differential GPS with safe in cost and time. For many years, PPP users depended on GPS (American system) which considered the solely reliable system. GLONASS’s contribution in PPP techniques was limited due to fail in maintaining full constellation. Yet, GLONASS limited observations could be integrated into GPS-based PPP to improve availability and precision. As GLONASS reached its full constellation early 2013, there is a wide interest in PPP systems based on GLONASS only and independent of GPS. This paper investigates the performance of kinematic PPP solution for the hydrographic applications in the Nile river (Aswan, Egypt) based on GPS, GLONASS and GPS/GLONASS constellations. The study investigates also the effect of using two different observation types; single-frequency and dual frequency observations from the tested constellations.

3

Sieć TPI NETpro

Mazippus M., Malczewski A.

Geodeta : magazyn geoinformacyjny

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2014

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nr 6

43

4

Analiza dostępności i dokładności pozycjonowania GPS/GLONASS w czasie rzeczywistym w trudnych warunkach obserwacyjnych

Ciećko A., Maliszewski P.

Logistyka

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2011

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nr 6

PL

W niniejszym artykule podjęto próbę zbadania wpływu trudnych warunków obserwacyjnych na pomiary wykonywane techniką RTK (Real Time Kinematic). Badania przeprowadzono w trybie statycznym na trzech stanowiskach w różnych warunkach terenowych. Na każdym z punktów przeprowadzono dwie, godzinne sesje pomiarowe wykorzystując do tego raz satelity systemów GPS i GLONASS natomiast w drugiej uwzględniono tylko satelity GPS. Przeprowadzenie sesji obserwacyjnych o tych samych porach dnia, przy wykorzystaniu odbiornika dwusystemowego pozwoliło na stwierdzenie, czy zwiększenie liczby obserwowanych sygnałów satelitarnych o sygnały systemu GLONASS poprawia dostępność i dokładność pomiaru w miejscach z licznymi zasłonami terenowymi.

EN

The article presents an approach to examine the impact of difficult observation conditions on RTK (Real Time Kinematic) measurements. The study was conducted in static mode on three sites in a variety of field conditions. On each of the points there were two, one-hour test sessions using once the GPS and GLONASS satellites, while the second included only GPS satellites. Carrying out observation sessions in the same times of day, using a dual-system receiver made it possible to determine whether the observed increment of the number of satellite signals by GLONASS signals improves the availability and accuracy in areas with numerous terrain obstructions.