Related Experiment Video
Updated: Jul 30, 2026
10:00
Calibration of Vector Network Analyzer for Measurements in Radio Frequency Propagation Channels
Published on: June 2, 2020
Absolute calibration of a geodetic time transfer system
John Plumb1, Kristine M Larson, Joe White
1University of Colorado, Department of Aerospace Engineering Sciences, Boulder, CO 80309, USA.
Summary
A new absolute calibration technique enhances geodetic Global Positioning System (GPS) receiver accuracy. This method achieves high precision, with uncertainty budgets of 1.1 ns and experimental agreement of 0.8-1.2 ns.
Area of Science:
- Geodesy and Geophysics
- Satellite Navigation Systems
Background:
- Accurate timing is crucial for geodetic Global Positioning System (GPS) applications.
- Existing calibration methods may lack sufficient precision for high-accuracy positioning.
Purpose of the Study:
- To develop and validate an absolute calibration technique for geodetic GPS receivers.
- To quantify the uncertainty associated with the calibration system.
Main Methods:
- Development of an absolute calibration system including receiver, cables, connectors, and antenna.
- Evaluation of the system's uncertainty budget across different frequencies.
- Analysis of calibration data using a short baseline experiment.
Main Results:
- The system's uncertainty budget was determined to be 1.1 nanoseconds (ns) at each frequency.
- A two-receiver experiment yielded an uncertainty of 1.6 ns.
- Data analysis on a short baseline showed agreement of 0.8 ns for P1 and 1.2 ns for P2.
Conclusions:
- The developed absolute calibration technique provides high accuracy for geodetic GPS receivers.
- The uncertainty budget analysis confirms the system's reliability for precise measurements.
- Experimental validation demonstrates the technique's effectiveness in achieving precise timing agreements.
Related Concept Videos
01:12Instrument Calibration
Instrument calibration is essential for ensuring that instruments produce accurate and consistent results. It is vital in manufacturing, healthcare, testing laboratories, and scientific research. Calibration processes are specific to each instrument and help enhance data accuracy. Each instrument has a unique calibration process tailored to its design and function to improve data accuracy.
Analytical Balance Calibration
An analytical balance measures mass and requires regular calibration to...
Analytical Balance Calibration
An analytical balance measures mass and requires regular calibration to...
01:15Distance Corrections
To achieve precise distance measurements, especially in surveying and construction, certain corrections must be applied to account for potential sources of error like the standardization errors, temperature variations, and slope adjustments.Standardization error emerges when measurement equipment undergoes changes, such as wear, repairs, or weather impacts. To address this, surveyors compare the equipment’s readings to a standard. This process identifies any deviation that might lead to...
01:30Introduction to Global Positioning System
The Global Positioning System (GPS) revolutionized positioning on Earth, providing precise location data through satellite ranging. The GPS system was developed in 1978 by the U.S. Department of Defense for military use, and it became available for civilian applications in 1983, transforming fields including navigation, fleet management, and time synchronization for telecommunications systems.GPS consists of satellites in medium Earth orbit, about 20,200 kilometers above the surface,...
01:28Geoid and Ellipsoid
The Earth's shape is best described as an ellipsoid, a slightly flattened sphere created by rotating an ellipse around its minor axis. This flattening results in the polar axis being about 21 kilometers shorter than the equatorial axis. In contrast, the geoid represents the Earth's gravitational shape and aligns with the mean sea level (MSL). The geoid is an irregular equipotential surface where gravity is perpendicular at every point. Variations in Earth's mass distribution cause geoid...
01:30Types of Global Positioning System Surveys
GPS surveying methods vary in application, accuracy, and data collection techniques, catering to diverse surveying and mapping needs. Static GPS, kinematic GPS, and real-time kinematic (RTK) surveying are widely used. Each technique offers distinct advantages.Static GPS involves placing one receiver at a known reference point and another at the target point. It collects exact positional data by observing multiple satellite ranges over an extended period, achieving centimeter-level accuracy for...
01:30Design Example: Identifying the Locations of Monuments in the Field Using Global Positioning System Device
Surveyors use Global Positioning System (GPS) technology to measure the precise location and elevation of points on Earth. In a recent survey, GPS receivers were used to determine the coordinates and elevations of two park monuments. The process involved careful mission planning, data collection, and correction to ensure accuracy. The survey began with mission planning to identify optimal satellite visibility and minimize Position Dilution of Precision (PDOP). A geodetic control point served as...