
GPS Signal Analysis & Receiver Diagnostics
Diagnose GPS receiver issues and optimize signal quality
What You Can Do
Parse GPS receiver logs, compute satellite geometry metrics (DOP, visibility), and identify signal quality problems. Diagnose receiver hardware and configuration issues, generate actionable troubleshooting steps, and provide signal strength analysis across satellite constellations to restore reliable positioning.
Features
Extract timing, position, and raw signal data from NMEA, u-blox, SiRF formats
Calculate GDOP, PDOP, HDOP, VDOP to assess positioning accuracy potential
Track C/N0 (carrier-to-noise) for GPS, GLONASS, Galileo, and BeiDou satellites
Diagnose clock bias, antenna problems, LNA faults, and RF interference patterns
Map symptoms to root causes with ranked corrective actions
Validate fixes and quantify improvement in signal stability and accuracy
Plot elevation/azimuth windows and track availability over time windows
Create actionable recommendations for antenna relocation, configuration tuning, or hardware replacement
Example Output
Example 1: Signal Quality Diagnosis
Your GPS receiver logs show:
- Median C/N0: 38 dB-Hz (acceptable range: 40–50)
- GDOP: 2.1 (good geometry)
- Issue: Low signal strength on GPS satellites above 45° elevation
- Diagnosis: Likely antenna obstruction or weatherproofing seal failure
- Recommendation: Inspect antenna connector; reseat or replace connector
Example 2: Receiver Configuration Problem
Analyzing 24-hour log:
- Fix Type: 3D Fixed ✓ (expected)
- Position Stability: σ = 1.2 m (unstable — normal: 0.5 m)
- Timing Drift: +45 PPM over 12 hours (excessive — clock bias likely)
- Root Cause: Receiver oscillator aging or PLL bandwidth misconfiguration
- Action: Recalibrate receiver time reference; check PLL filter settings
What's Included
- SKILL.md: Full GPS analysis workflow and diagnostic decision logic
- Log Parser Template: Handles NMEA, u-blox, and SiRF receiver formats
- Diagnostic Decision Tree: Step-by-step checklist for symptom-to-root-cause mapping
- Signal Quality Worksheet: C/N0 analysis, DOP calculation, and geometry assessment
- Satellite Visibility Plotter: HTML/JavaScript template to visualize elevation/azimuth windows
- Before/After Comparison Template: Track metrics across diagnostic sessions
- Report Generator: Markdown template for exporting findings with recommendations
Who It's For
- GPS/GNSS Receiver Engineers — Troubleshoot embedded receiver firmware and hardware
- UAV/Drone Developers — Diagnose positioning accuracy loss during flight testing
- IoT/LoT Platform Teams — Debug location service failures in edge devices
- Cellular & Telecom Engineers — Optimize base station timing and signal distribution
- Autonomous Vehicle Perception Teams — Validate GNSS subsystem performance in pre-deployment testing
Best For
- Troubleshooting persistent GPS lock loss — Rapid diagnosis from receiver logs
- Validating receiver firmware updates — Benchmark signal quality before and after tuning parameter changes
- Pre-deployment antenna site surveys — Assess obstruction, multipath, and signal strength at proposed locations
- Diagnosing multi-constellation interference — Analyze GPS/GLONASS/Galileo signal conflicts and band conflicts
- Root-cause analysis during field testing — Extract actionable insights from 24–48 hour log captures






