Examining quality of DGNSS derived positioning in data in urban city -- A case study of an urban city in India

TL;DR

This study evaluates the accuracy of DGNSS positioning in an Indian urban environment using multiple GNSS constellations and post-processing, achieving centimeter-level precision for ground control points.

Contribution

It presents a comprehensive methodology combining multi-constellation GNSS data, CORS network, and post-processing to attain high-precision DGNSS positioning in urban areas.

Findings

Achieved millimeter to centimeter level positional accuracy.

Utilized multi-constellation GNSS including GPS, GLONASS, Galileo, BeiDou.

Demonstrated effective post-processing techniques for urban DGNSS data.

Abstract

GNSS observations are carried out in static mode/ Differential global navigation satellite system (DGNSS) and dynamic mode / Real time Kinematics (RTK) mainly. RTK mode of observation is useful in case of navigation whereas in order to determine very precise positioning, static / DGNSS/ DGPS mode is recommended. In this study, we have examined the quality of DGNSS survey of an urban city in India over ~300 Ground Control Points. Survey is carried out in DGNSS mode with dual frequency mode. All the observations were recorded using GPS, GLONASS , Galileo and Beidu with GDOP values in the range of 1.4 to 2.5. Beidu was used in broadcast ephemeris mode whereas for other constellations, precise orbit ephemeris were obtained from International GNSS service (IGS) site as per the observation day and month. Further, all the data was post processed in the SW suite and positional and vertical accuracies of millimeter to few centimeter level were obtained. This paper describes the approach of Ground Control Point (GCP) identification, surveying, methodology, use of CORS network and data post-processing in order to achieve such a precise accuracies in the urban city.