Related Experiment Video
Updated: Apr 28, 2026
09:36
Continuous-Wave Propagation Channel-Sounding Measurement System - Testing, Verification, and Measurements
Published on: June 25, 2021
2.7K
Normalized GNSS interference pattern technique for altimetry.
Miguel Angel Ribot1, Jean-Christophe Kucwaj2, Cyril Botteron3
1Electronics and Signal Processing Laboratory (ESPLAB), École Polytechnique Fédéralede Lausanne (EPFL), Maladière 71B (Microcity), CH-2002 Neuchâtel, Switzerland. miguel.ribotsanfelix@epfl.ch.
Sensors (Basel, Switzerland)
|June 13, 2014
Summary
This study introduces a new method using Global Navigation Satellite Systems (GNSS) reflected signals for faster antenna height estimation in altimetry. The technique improves accuracy by normalizing signal-to-noise ratio variations.
Area of Science:
- Geodesy and Geophysics
- Satellite Remote Sensing
Background:
- Global Navigation Satellite Systems (GNSS) reflected signals are utilized for altimetry, including water level and snow height monitoring.
- The interference pattern technique (IPT) uses signal-to-noise ratio (SNR) oscillations to determine distances, but is limited by estimation time.
Purpose of the Study:
- To develop an alternative model for SNR variations using normalized measurements.
- To define a maximum likelihood estimate for antenna height estimation, reducing measurement time.
Main Methods:
- Normalization of GNSS reflected signal measurements.
- Development of a new SNR variation model.
- Maximum likelihood estimation for antenna height.
- Derivation and application of the Cramér-Rao lower bound for sensitivity analysis.
Main Results:
- A novel method for estimating antenna height from GNSS signals is proposed.
- The new method significantly reduces the estimation time required per SNR variation cycle.
- Sensitivity analysis using the Cramér-Rao lower bound provides insights into parameter influence.
Conclusions:
- The proposed normalized measurement approach offers a more efficient method for antenna height estimation using GNSS.
- The technique is validated experimentally using real GPS L1 C/A signals.
- This advancement has implications for various altimetry applications requiring precise height measurements.
Related Concept Videos
01:26Errors in Global Positioning System
460
Global Positioning System (GPS) technology has revolutionized navigation and positioning, but its accuracy is often compromised by various errors. These errors, stemming from environmental, satellite, and receiver-related factors, require careful mitigation to ensure reliable performance across applications.Atmospheric ErrorsGPS signals travel through the Earth’s ionosphere and troposphere, introducing delays which affect accuracy. The ionosphere is strongly influenced by charged particles,...
460
01:29Application of Linearization and Approximation
192
A drone flying through complex terrain often relies on more than one sensing method to estimate small changes in altitude. Along with direct measurements, air pressure provides a useful indirect indicator of vertical movement. Atmospheric pressure decreases as altitude increases, and this relationship is commonly described using an exponential model. Although accurate, converting pressure measurements into altitude values requires calculations that are too complex to perform repeatedly during...
192
01:28Geoid and Ellipsoid
1.3K
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...
1.3K
01:30Design Example: Identifying the Locations of Monuments in the Field Using Global Positioning System Device
453
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...
453
01:28Field Application of Global Positioning System
401
The Global Positioning System (GPS) has become an indispensable tool in fieldwork, offering unparalleled precision and efficiency for surveying, navigation, and infrastructure development. By harnessing signals from a constellation of satellites, GPS receivers determine the location of objects with remarkable speed and accuracy, often completing calculations within a second.Advantages of Modern GPS TechnologyContemporary GPS receivers are designed to meet the practical demands of field...
401
01:17Common Leveling Mistakes and Errors
671
A survey team is tasked with determining the elevation difference between points Point A and Point B, separated by uneven terrain. They use a leveling instrument and a leveling rod.Common MistakesMisreading the Rod: During a backsight reading at Point A, the instrumentman observes the rod partially obscured by tall grass. Instead of reading 1.135 m, they mistakenly record 1.735 m due to the misalignment of the crosshair with the wrong graduation. This error adds 0.600 m to all subsequent...
671