GNSS FOR PRECISION GEOMONITORING
GNSS Fundamentals
Global Navigation Satellite System (GNSS) technology enables precise positioning by measuring signals transmitted from orbiting satellites. It underpins applications ranging from navigation and surveying to deformation and stability monitoring.
What is GNSS?
GNSS is a satellite-based positioning technology that determines location using signals from multiple global satellite constellations, including GPS (United States), GLONASS (Russia), Galileo (European Union), and BeiDou (China).
Each constellation consists of dozens of satellites orbiting Earth, allowing receivers to track many satellites simultaneously.
By combining these signals, GNSS receivers compute:
- Position (X, Y, Z)
- Time
- Movement over time
Unlike optical systems, GNSS does not require line-of-sight between monitored points, making it well suited to large or distributed environments.
How GNSS Enables Precision Monitoring
GNSS satellites broadcast signals containing their position and precise timing. Ground receivers analyse these signals to estimate distance, 3D position (X, Y, Z), and time.
While basic positioning supports navigation, high-precision GNSS refines measurements by analysing carrier wave signals and combining observations over time.
Advances in constellations, receiver technology, and geodetic processing have transformed GNSS into a technique capable of detecting subtle positional change.
This enables engineers to determine whether a point has moved, by how much, and in what direction.
Achievable precision depends on equipment quality, observation strategy, network design, and data processing.
What GNSS Does Well
GNSS is uniquely suited to monitoring applications because it measures true 3D position directly, rather than inferring movement from imagery or relative geometry.
When designed and processed correctly, GNSS provides:
Why Methodology Matters
There are two primary GNSS methods used for high-precision positioning in mining and civil monitoring:
(often referred to as Real-Time Kinematic or RTK)
Provides rapid positioning using real-time corrections transmitted from a base station.
- Surveying & machine control
- Short observation periods
- Fast, in-field positioning
Accuracy is typically centimetre-level. Short observation windows and reliance on real-time corrections can make results more sensitive to signal noise and environmental conditions.
(often referred to as Post-Processed Kinematic (PPK) or Post-Processed Static)
Positions are derived by processing stored GNSS observations over longer durations.
- Millimetre-scale precision
- Higher statistical confidence
- Improved ambiguity resolution
- Stronger trend detection over time
Longer observation periods provide greater signal redundancy, enabling more robust positioning and improved resistance to noise.
Kurloo applies near-real-time post-processing to transform GNSS observations into stable, validated displacement time series, delivered within minutes of each observation period.
By preserving raw observations and applying rigorous geodetic processing, statistical quality control, and expert oversight, Kurloo ensures measurements remain precise, consistent, and defensible by design.
This approach provides a more robust foundation for monitoring than real-time positioning alone, particularly where measurement integrity and trend reliability are critical.
Environmental & Practical Considerations
GNSS is a powerful measurement technology, but like any precision instrumentation, performance depends on environmental and design factors.
The critical influence of design and methodology on GNSS outcomes is well understood. When network design, site selection, hardware, and processing methods are carefully selected and managed over time, GNSS delivers highly stable, accurate results.
Sky Visibility & Obstructions
GNSS receivers calculate position using simultaneous signals from multiple satellites distributed across the sky. Terrain, high walls, structures, and dense vegetation can partially block these signals.
Obstruction of low-elevation satellites may reduce solution stability, particularly where satellite geometry becomes constrained.
Why this matters
Reduced satellite visibility can increase noise, slow ambiguity resolution, and affect short-term precision if not accounted for.
How Kurloo manages this
Kurloo specialists assess sky visibility during site design, selecting device locations, monumentation for monitoring, and reference stations that optimise satellite availability.
Where obstructions are unavoidable, Kurloo’s longer observation windows and statistical processing help maintain optimal accuracy and consistency.
Signal Reflections (Multipath)
Reflected GNSS signals, rather than direct signals to the antenna phase centre, can occur due to vegetation, deep excavation, or benching. They can also be caused by man-made structures like steelwork, buildings, tanks, or heavy machinery. These reflected signals travel longer paths before reaching the antenna, causing the positioning quality to degrade. Shorter observation segments are more susceptible to variations due to a higher multipath.
Why this matters
Multipath is a major contributor to errors in GNSS positioning, particularly over shorter observation methods such as RTK. Multipath can introduce small biases and increased variability in position estimates, especially in highly reflective environments.
Kurloo mitigates multipath through
- Careful antenna placement and mounting design
- Avoidance of high-risk reflective surfaces where practical
- Use of professional-grade GNSS antennas and hardware designed to reduce multipath interference (reflections of signals)
- Advanced post-processing algorithms that identify and suppress multipath artifacts
Kurloo’s expert post-processing and data validation delivers defensible results. Multipath impacts can be more thoroughly quantified and mitigated than with RTK or edge processing without oversight.
Atmospheric Effects
GNSS signals travel through the ionosphere and troposphere, where atmospheric variability causes small signal delays.
Why this matters
Unmodelled atmospheric effects reduce achievable precision and may introduce apparent short-term movement.
How Kurloo manages this
Kurloo’s processing workflows mitigate atmospheric effects
- Multi-frequency observations
- Established atmospheric modelling techniques, where Kurloo’s post-processing methodology allows atmospheric effects to be inspected and compared over longer periods. This provides greater resilience to atmospheric fluctuations than real-time methods.
- Long-duration observation windows
- Reference station differencing
These methods cancel common errors and stabilise millimetre-scale displacement estimates.
Network Geometry & Baseline Design
GNSS precision depends on the geometric relationship between monitoring stations and reference stations.
Long baselines or poor geometry can reduce precision and consistency across a site.
Why this matters
Accuracy potential shown in data sheet specifications assumes appropriate network design.
How Kurloo manages this
Kurloo designs site-specific geodetic networks, optimising:
- Baseline lengths
- Reference station positioning
- Redundancy and stability
- Monitoring geometry aligned to failure mechanisms
For high-precision applications, Kurloo typically maintains monitoring stations within defined distances (e.g. ~2 km) of reference stations to preserve millimetre performance.
Point-Based Measurement
GNSS measures movement at discrete sensor locations. It does not directly capture behaviour between those points.
Why this matters
Sparse sensor placement may miss localised deformation.
How Kurloo manages this
Kurloo applies risk-based network density design, considering:
- Failure mechanisms
- Structural geometry
- Historical behaviour
- Critical assets
GNSS is integrated with complementary technologies (radar, InSAR, laser scanning, LiDAR, drones, and routine visual inspection) where broader coverage or spatial context is required.
Interference & Signal Quality
GNSS signals are low-power radio transmissions. Interference, accidental or deliberate, may degrade GNSS signal quality.
Why this matters
Undetected interference can reduce data reliability.
How Kurloo manages this
Unlike RTK results, Kurloo’s post processing methods are more resilient to the presence of jamming and spoofing in results. These effects are evident in the raw GNSS signal data Kurloo collects.
Kurloo systems include:
- Signal quality monitoring
- Interference detection indicators
- Automated quality controls
- Expert review of anomalies
Data irregularities are assessed in context before influencing movement interpretation.
Access, Installation & Operational Constraints
Ideal monitoring locations may present safety, access, or operational challenges.
Why this matters
Practical deployment constraints influence sensor placement strategy.
How Kurloo manages this
Kurloo delivers greater simplicity and practicality through hardware designed to deploy easily in minutes.
Kurloo balances:
- Measurement objectives
- Site safety requirements
- Access limitations
- Operational workflows
Alternative placements, mounting strategies, and network adjustments maintain data integrity while supporting safe installation.
Sensors can be moved or repurposed as site conditions change, reducing time spent in hazardous areas and avoiding constraints cause by fixed instrumentation.
Kurloo achieves high-precision geomonitoring through expert system design, not sensors alone.
As a geomonitoring system that manages data integrity, Kurloo ensures factors that would otherwise limit the reliability and accuracy of GNSS technology are continuously addressed. delivering validated displacement trends suitable for defensible engineering decisions.
Why Managed GNSS Matters
Reliable monitoring outcomes depend on far more than GNSS technology.
Extracting consistent, positional data requires specialist expertise in network design, signal quality management, and advanced geodetic processing, disciplines not typically embedded within standard GNSS deployments.
Kurloo’s integrated managed GNSS service makes your data defensible by design.
Continuous Monitoring
Autonomously captures position at defined intervals to reveal subtle movement trends over time.
True 3D Displacement
Measures vertical and horizontal movement to resolve full vectors of motion.
Absolute Reference Frame
Anchors measurements to a global coordinate system for consistent comparison across time and datasets.
All-Weather Operation
Unaffected by rain, dust, fog, or lighting conditions.
Scalable Site Coverage
Works across large or distributed areas without requiring line-of-sight between sensors.
Trend-Based Insight
Supports detection of gradual change, not just threshold breaches.
GNSS as a Reference Layer
Complex ground motion will require a combination of instrumentation and methods based on site conditions and risk profile.
Kurloo’s GNSS geomonitoring at key points provide a stable reference layer, strengthening confidence when integrating multiple data sources.
| Technology | Primary Contribution |
|---|---|
| GNSS | Continuous high-precision absolute 3D measurements |
| Total Stations | High-precision relative 3D measurements |
| InSAR | Wide-area deformation patterns |
| In-situ instruments | Localised high-precision subsurface sensor data |