DGPS Survey
High-Accuracy Differential GPS (DGPS) Technology
A Differential Global Positioning System (DGPS) is an upgraded form of GPS that significantly enhances positional accuracy—improving the nominal GPS accuracy of nearly 15 metres to an impressive 1–3 centimetres in advanced implementations. This makes DGPS one of the most reliable technologies for land surveying, mapping, and engineering applications across Delhi, Noida, Gurgaon, and Faridabad.
How DGPS Ensures High-Precision Location Data
Each DGPS system operates through a network of fixed, ground-based reference stations that broadcast correction signals. These signals represent the difference between the GPS satellite-calculated positions and the known fixed coordinates on the ground.
Survey receivers use these corrections to adjust pseudo-range measurements, delivering highly accurate positional data. These digital correction signals are typically transmitted locally via short-range terrestrial transmitters, ensuring real-time and post-processed accuracy.
Principle of DGPS Surveying
A DGPS survey uses two receivers simultaneously to eliminate common GPS errors.
Key components include:
Ground Control Points (GCPs)
GCPs are physical locations on the earth’s surface with precisely known X, Y (latitude, longitude) and Z (elevation above mean sea level) coordinates. These points must be extremely accurate for ortho-rectification, construction layout, engineering design, and all professional survey applications.
Low-cost handheld GPS devices or smartphones cannot deliver the required accuracy. Instead, survey-grade differential GPS devices are essential, as they lock onto multiple satellites and accurately triangulate ground positions.
Baselines
Baselines are three-dimensional lines connecting two GPS antenna locations. Since most GPS errors affect both receivers equally, post-processing or real-time computations eliminate shared errors, resulting in highly precise location data.
RTK (Real Time Kinematic) DGPS
Certain GPS receivers can perform real-time DGPS measurements using RTK technology, where a separate radio receiver provides instant correction signals. This allows for immediate on-site high-accuracy positioning, widely used in land surveying in Delhi, Noida, Gurgaon, and Faridabad.
DGPS Survey Expertise by C&G Survey Technical Services
C&G SURVEY TECHNICAL SERVICES uses 15 survey-grade, dual-frequency Trimble and Leica RTK DGPS receivers to deliver highly accurate survey results.
Key practices include:
Observation of all GCPs in static mode for optimal accuracy
Compliance with industry-standard triangulation methods
High-precision results for topographical surveys, engineering projects, GIS mapping, and infrastructure planning
RTK-based control point generation for satellite image ortho-rectification requiring 2–5 cm accuracy
We provide reliable, high-precision DGPS survey services across Delhi, Noida, Gurgaon, and Faridabad, ensuring accurate measurements for construction, land development, planning, and mapping projects.