Tech Chat | How accurate can GNSS achieve without base stations?
In most applications of GNSS positioning, we usually use RTK technology to obtain centimeter-level precise positioning. The principle of RTK is to use the correction data from base stations or CORS to correct the positioning data for higher accuracy. But without these base stations, do you know how accurate GNSS can be?
In today's blog, we will introduce the original accuracy of GNSS single-point mode and two optimized methods to obtain higher accuracy without base stations.
1. Single Point Mode
The single-point mode is the positioning accuracy obtained by GNSS without any correction and optimization, which can reach meter-level accuracy. GNSS modules/receivers with better performance on the market can generally achieve an accuracy of about 2-3m.
In our daily life, the built-in GPS chip of our mobile phone adopts the single-point positioning mode, which can meet the needs of daily map navigation.
2. SBAS Mode
The principle of SBAS mode is quite like RTK, it receives GNSS and SBAS signals at the same time, eliminating regional error to obtain higher accuracy.
Learn more about SBAS: Tech Chat | What is SBAS?
Different from the RTK base station that particularly corrects rover in certain range (>20km), the SBAS mode is a regional correction that can cover multiple countries or a continent. Therefore, the improvement of SBAS accuracy cannot reach the level of RTK.
Normally the accuracy of SBAS mode can reach <1m 3D RMS, which can be used for some GIS projects or agricultural navigation systems that do not strictly require high accuracy.
Learn more about SingularXYZ products that support SBAS mode.
https://www.singularxyz.com/Y1.html
https://www.singularxyz.com/P1.html
https://www.singularxyz.com/SV100.html
https://www.singularxyz.com/SAgro100_Automated_Steering_System.html
3. Doppler Smooth Mode
Except using correction data to improve the accuracy, there is also other way to use Doppler algorithms to improve the positioning accuracy.
During the movement of the terminal, the Doppler algorithm can smooth the GNSS positioning point according to the movement trajectory of the terminal, so as to achieve higher dynamic positioning accuracy. The accuracy of Doppler single-point smooth Mode can reach 15-30cm, which is suitable for some vehicle mounted systems that need dynamic positioning data, such as agricultural guidance systems.
Learn more about SingularXYZ products that support Doppler smooth mode,
https://www.singularxyz.com/SAgro10_GNSS_Guidance_System.html
https://www.singularxyz.com/S10.html
https://www.singularxyz.com/Single_Point_Smooth_Positioning_Solution.html
