🛰️ OSNMA-Enabled Satellite Signals for PIC2BIM iOS — Detailed Analysis#
This document provides a comprehensive analysis of how OSNMA (Open Service Navigation Message Authentication) is used in the PIC2BIM iOS application to enable trusted GNSS-based geolocation.
🔍 Document Objective#
The document aims to outline the integration of OSNMA into the PIC2BIM iOS application by:
- Identifying the relevant Galileo signals and satellites (PRNs).
- Explaining the purpose and functionality of OSNMA.
- Providing a UK-specific context for visibility and use.
- Describing its technical integration into PIC2BIM iOS.
🧩 Functional Analysis#
✅ OSNMA Support in Galileo#
- Technology: OSNMA is a cryptographic authentication scheme provided by the Galileo GNSS.
- Signal: OSNMA is transmitted via Galileo E1B on 1575.42 MHz.
- Purpose: Ensures the authenticity of navigation messages, protecting against spoofing.
🛰️ Satellite-Specific Usage#
📋 PRNs Supporting OSNMA (in UK Context)#
| PRN | Satellite | Notes |
|---|---|---|
| E11 | GSAT0101 | ✅ OSNMA Capable |
| E12 | GSAT0102 | ✅ OSNMA Capable |
| E19 | GSAT0103 | ✅ OSNMA Capable |
| E20 | GSAT0104 | ✅ OSNMA Capable |
| E24 | GSAT0201 | ✅ OSNMA Capable |
| E25 | GSAT0202 | ✅ OSNMA Capable |
| E26 | GSAT0203 | ✅ OSNMA Capable |
| E27 | GSAT0204 | ✅ OSNMA Capable |
| E30 | GSAT0205 | ✅ OSNMA Capable |
| E31 | GSAT0206 | ✅ OSNMA Capable |
These satellites frequently appear above the horizon in the UK and are compatible with OSNMA. Visibility depends on constellation health, user location, and satellite geometry.
📱 Integration in PIC2BIM iOS#
App-Specific Workflow#
- Signal Capture: Receives E1B signals from the Galileo satellites.
- Message Parsing: Extracts navigation and authentication content.
- Validation: Verifies digital signatures via OSNMA protocol.
- Integration: - Validated signals are logged. - OSNMA status is embedded in geotagged photo metadata. - Used for trusted location documentation.
🛡️ Security & Integrity Benefits#
| Feature | Description |
|---|---|
| Spoofing Detection | Ensures authenticity of satellite signal |
| Message Integrity | Confirms trust in positioning messages |
| Data Confidence | Adds assurance in audits and regulatory reporting |
🌍 Use in the UK#
- OSNMA-enabled satellites are frequently visible across the UK.
- Suitable for field use in infrastructure inspection, construction, and geospatial asset management.
GNSS planning tools like GPSTest or GNSS View can validate current PRNs overhead.
📌 Summary#
- Signal Used: Galileo E1B
- Satellites: PRNs E11–E31
- App Role: Enables trusted, secure geotagging in PIC2BIM iOS
- Security Outcome: Authentication of navigation messages using OSNMA ensures data integrity and spoofing resistance in critical GNSS applications.