Study of Reliable Rapid and Ultrarapid Static GNSS Surveying for Determination of the Coordinates of Control Points in Obstructed Conditions

This paper presents a method for the surveying and reliable processing of Global Navigation Satellite System (GNSS) observations in rapid and ultrarapid static surveying for determination of control-point coordinates. The presented technique allows for reliable determination of coordinates, even in the case of highly difficult observation conditions (e.g., for control points situated along forest edges or entirely in the forest, near buildings, or in the vicinity of power-transmission lines). The paper also analyzes different projects of the global positioning system (GPS/GLONASS) networks from the perspective of their credibility and reliability. The control-point coordinates are determined by three GNSS receivers positioned in line on a special base, providing a credible control of GNSS baselines during rapid and ultrarapid static surveys. The GNSS receivers are separated by the distance of 0.5 m. Given the gross errors in baseline coordinates determined that happen in practice, simultaneous use of three receivers for position determination of a control point allows reliable determination of the coordinates even under significantly obstructed access to satellites. The practical surveys were conducted using Topcon and Trimble receivers using real and virtual reference stations. The presented survey and GNSS data-processing methodology allow obtaining centimeter-level accuracy in a few minutes of GPS/GLONASS observations for control points located in obstructed conditions.