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Work Assignment 2: Critical Product Mapping Report
Version: 2.6
Date: 22 July 2026
Prepared by: UN-GGCE Technical Consulting Team
Reference: Terms of Reference 2 (ToR2) — Work Assignment 2
Supersedes: Version 2.5 (23 July 2026)
Audience
This report serves two readerships: (1) UN-GGCE leadership and technical counterparts already familiar with this engagement; and (2) UN-GGCE staff and Member State stakeholders new to this specific analysis. Readers new to the engagement should read this Purpose and Reading Guide; the sections that follow provide the full technical detail underlying its conclusions.
Purpose and Reading Guide
This report is one of five deliverables produced under Terms of Reference 2 (ToR2) of the UN-GGCE consultancy engagement, the Global Geodesy Supply Chain Assessment. Work Assignment 2 requires the mapping of the end-to-end delivery workflows for the five critical geodetic products, expressed using the Essential Geodetic Variables (EGV) framework, so that risks and investment priorities can be assessed in Work Assignments 3 through 5.
This assessment builds directly on the State of Geodesy 2026: A baseline maturity assessment (UN-GGCE, 16 March 2026)[^sog2026] — the first comprehensive maturity assessment of the global geodesy supply chain, developed through consultation with more than 130 experts across the international geodetic community. The State of Geodesy 2026 established the capability maturity baseline; this report takes the next step, applying that baseline to the structure of the supply chain itself to identify where risk concentrates and where investment will have the greatest effect.
In plain terms: the global geodesy supply chain is the international network of observatories, data centres, analysis centres, and combination centres that produces the reference frames, satellite orbits, Earth orientation parameters, and gravity models on which satellite navigation, Earth observation, surveying and mapping, and disaster response all depend. This report maps how each of five critical products is actually produced — tier by tier, institution by institution — and scores where each production chain is most exposed to failure.
Companion Documents
For readers who are new to this engagement, four companion documents provide the necessary context:
- Work Assignment 1 Appendix — EGV Data Levels and Supply Chain Tiers — explains how geodetic product workflows are structured into data levels and supply chain tiers. Read this first.
- Work Assignment 1 — Guiding Principles — the six principles against which supply chain design is assessed.
- Work Assignment 1b — Investment Prioritization and Risk Rubric — the two-track framework used to score risk and sequence investment. Every numeric score in this report is produced by that framework.
- Work Assignment 2 Annexes (five Workflow Description documents) — the detailed, tier-by-tier basis for each product's summary in Sections 3–7 below.
Key Terms
| Abbreviation | Full term |
|---|---|
| ACC | Analysis Centre Coordinator (IGS) — combines independent orbit solutions from multiple Analysis Centres into the single official product (Tier 3); distinct from CDDIS, which only archives and distributes data (Tier 1) |
| Bulletin A / Bulletin B | Earth Orientation Parameter products: Bulletin A is a rapid series published weekly by USNO for near-real-time use; Bulletin B is the final, definitive monthly series published by SYRTE (see Section 5) |
| CDDIS | Crustal Dynamics Data Information System (NASA GSFC, USA) — one of three Global Data Centres that archive and distribute raw and processed geodetic data (Tier 1); does not perform combination |
| EGV | Essential Geodetic Variable |
| EOP | Earth Orientation Parameters |
| GNSS | Global Navigation Satellite Systems |
| ICRF | International Celestial Reference Frame |
| IERS | International Earth Rotation and Reference Systems Service |
| IGN | Institut national de l'information géographique et forestière (France) |
| IGS | International GNSS Service |
| ITRF | International Terrestrial Reference Frame |
| IVS | International VLBI Service for Geodesy and Astrometry |
| PPTD | People, Process, Technology, Data (capability maturity dimensions) |
| SLR | Satellite Laser Ranging |
| SPOCC | Satellite orbit combination software operated for the IGS (GFZ Potsdam) |
| VLBI | Very Long Baseline Interferometry |
1. Introduction
This report constitutes the Work Assignment 2 (WA2) deliverable under the Terms of Reference 2 (ToR2) of the UN-GGCE Global Geodesy Supply Chain Assessment engagement. It provides a structured, evidence-based assessment of five critical Essential Geodetic Variable (EGV) product pipelines — Satellite Orbits, the International Terrestrial Reference Frame (ITRF), Earth Orientation Parameters (EOP), the International Celestial Reference Frame (ICRF), and the Global Earth Gravity Field — drawing on the capability maturity baseline published in the State of Geodesy 2026[^sog2026], together with the tier risk scores and workflow topology descriptions developed in this engagement.
The analysis is grounded in the six Guiding Principles established in Work Assignment 1 (Guiding Principles, v2.1, May 2026) and their foundational precedents in the UN-GGIM Integrated Geospatial Information Framework (IGIF)[^igif], the WMO Unified Data Policy[^wmo], and the Sendai Framework for Disaster Risk Reduction[^sendai]. The six principles are:
- Principle 1: Geographic Distribution for Technical Performance
- Principle 2: Political Resilience and Distributed Operational Control
- Principle 3: Centralised Accountability through Multilateral Governance
- Principle 4: Technical Interoperability and Data Accessibility
- Principle 5: Minimum Capability Maturity Standards
- Principle 6: Transparency and Performance Accountability
The five EGV pipelines assessed in this report span EGV Levels 2 and 3 in the GGOS EGV framework (V7.0, January 2026) and collectively constitute the core of the global geodesy supply chain. Their workflows are formally described in the following documents, each updated as part of WA2 with disaggregated PPTD data and Principle citations:
- Satellite Orbits Workflow (Work Assignment 2 Annex, v5.5)
- ITRF Workflow (Work Assignment 2 Annex, v3.5)
- EOP Workflow (Work Assignment 2 Annex, v3.5)
- ICRF Workflow (Work Assignment 2 Annex, v3.5)
- Global Gravity Model Workflow (Work Assignment 2 Annex, v3.3)
All capability maturity scores reported in this document are drawn from the published State of Geodesy 2026[^sog2026]. All tier risk scores were computed using the operational track of the two-track investment prioritisation framework developed in June 2026 and documented in Work Assignment 1b (Investment Prioritisation and Risk Rubric, v3.1). The operational formula is:
Tier Risk Score = PPTD Gap × Step CriticalityWhere PPTD Gap = 5 − tier_PPTD_avg (a straight unweighted average across the four People, Process, Technology, and Data dimensions), and Step Criticality is an integer 1–5 reflecting the degree of single-point-of-failure concentration at that tier. The governance track of the framework assesses each tier qualitatively against Principle 2 (political concentration), Principle 3 (absence of a governing agreement or mandate), Principle 4 (proprietary critical-path software or restricted data), and Principle 6 (absence of independent monitoring). Governance findings are not scored numerically; they are reported in the Key Finding narrative for each workflow and elevate the urgency of tiers whose operational scores are already high.
2. Methodology
2.1 Capability Maturity Framework
The People, Process, Technology, Data (PPTD) capability maturity framework was developed during the first UN-GGCE consultancy engagement (Terms of Reference 1) and applied at full scale in the State of Geodesy 2026: A baseline maturity assessment[^sog2026], which assessed fifty-eight operational capabilities across the four dimensions on a 1–5 scale, where 1 represents no documented process or capacity and 5 represents optimised, continuously improving practice. The maturity results used throughout this report are those published in the State of Geodesy 2026, supplemented where noted by IGS Technical Reports (2013, 2018) and IAG/GGOS primary sources.
The published State of Geodesy 2026 is the authoritative source for all capability maturity scores in this assessment. All 58 scores have been calculated and stored in a database maintained for this engagement, verified 15 June 2026 against the published report.
2.2 Tier Risk Scoring
Tier risk scores were computed using the operational track of the two-track framework (Work Assignment 1b, Investment Prioritisation and Risk Rubric, v3.1), applied to twenty-five supply chain tiers across the five EGV workflows. Each tier's PPTD gap was computed as a straight unweighted average across all four dimensions of the capabilities linked to that tier. Step Criticality was assigned based on the architectural analysis in the workflow description documents, using the canonical reference point that the Satellite Orbits Tier 3 ACC/SPOCC combination engine is the archetype of a Step Criticality 5 single point of failure (validated by U.S. Government Shutdown records 2013, 2018–2019; IGSMAIL-6826[^igsmail]; IGS 2018 Technical Report[^igs2018]).
Governance risk is assessed on a separate, qualitative track. Each tier is examined for gaps against Principle 2 (political concentration), Principle 3 (absence of a governing agreement or mandate), Principle 4 (proprietary critical-path software or restricted data), and Principle 6 (absence of independent monitoring or performance reporting). Two tiers with identical operational scores can have materially different real-world risk profiles depending on the quality of their governance design; governance-track findings are therefore reported alongside every operational score and inform investment urgency, as set out in Part D of the Investment Prioritization and Risk Rubric.
Score classification thresholds:
| Score Range | Classification |
|---|---|
| ≥ 20 | Critical |
| 13–19.99 | High |
| 7–12.99 | Significant |
| 0–6.99 | Minor |
All 25 computed tier risk scores are documented in the UN-GGCE Supply Chain Risk Assessment (2026). Scores were calculated in a single scoring run dated 22 June 2026 and stored in a database maintained for this engagement; every score table in this report is drawn from that database.
2.3 Principle Citations
All principle citations in this report use the nomenclature established in WA1 (Principle N: [name]). Citations are applied wherever a supply chain gap or risk corresponds to a specific design requirement or implementation criterion defined in Work Assignment 1 (Guiding Principles, v2.1).
3. Satellite Orbits (EGV Level 2)
Workflow document: Satellite Orbits Workflow (Work Assignment 2 Annex, v5.5)
The Satellite Orbits supply chain produces the GNSS Satellite Orbits, Clocks and Biases (GOCB) product set — three-dimensional orbital trajectories and sub-nanosecond clock corrections for all operational GNSS satellites. As a Level 2 EGV, it is an upstream prerequisite for ten of fourteen Level 3 EGVs, including the ITRF, EOP, sea level, ice sheets, and terrestrial water storage. A critical circular dependency exists with the ITRF: each requires the other as a processing input, meaning failure in either pipeline degrades both.
The supply chain is structured across five tiers (Tier 0 through Tier 4) and is the subject of the most mature workflow documentation in the assessment, reflecting the depth of Phase 1 analysis. The key finding is that all decentralised resilience built across Tiers 0–2 converges at a single bottleneck: the Analysis Centre Coordinator (ACC) and the Software for Precise Orbit and Clock Combination (SPOCC) at Tier 3. This tier carries the highest tier risk score across all five EGV workflows.
Tier Risk Score Summary:
| Tier | PPTD Gap | Step Criticality | Risk Score | Classification |
|---|---|---|---|---|
| Tier 0 — Observation | 2.67 | 3 | 8.00 | Significant |
| Tier 1 — Data Centres | 2.70 | 4 | 10.80 | Significant |
| Tier 2 — Analysis Centres | 2.67 | 3 | 8.00 | Significant |
| Tier 3 — ACC/SPOCC Combination | 3.65 | 5 | 18.25 | High |
| Tier 4 — Validation & Distribution | 2.33 | 2 | 4.67 | Minor |
(UN-GGCE Supply Chain Risk Assessment, 2026)
Key Finding: Tier 3 (ACC/SPOCC Combination) is the highest-priority investment target in the entire global geodesy supply chain, carrying the highest tier risk score across all 25 assessed tiers: 18.25 (PPTD Gap: 3.65 × Step Criticality: 5). The PPTD gap is the highest of any tier in the assessment, driven by Risk Management (avg 1.00), Knowledge Management (avg 1.30), and Disaster Recovery and Supply Chain Continuity (avg 1.70) — all Phase 1 Priority capabilities. No formal backup ACC exists; SPOCC software knowledge is concentrated at GFZ; and the current ACC transition to NASA GSFC reintroduces U.S. federal political risk that the GA/MIT structure had successfully mitigated. On the governance track, this tier records gaps against Principles 2, 3, 4, and 6 simultaneously — the only tier in the assessment where all four governance-track principles are unmet. Under the rubric, governance findings of this severity elevate a High operational score to urgent: this tier is the unconditional first priority for governance action regardless of its numeric distance from the Critical band.
4. International Terrestrial Reference Frame (EGV Level 3)
Workflow document: ITRF Workflow (Work Assignment 2 Annex, v3.5)
The ITRF is the fundamental coordinate reference system of global geodesy — the Level 3 EGV realisation of the Global Reference Frames product, combining observations from GNSS, VLBI, SLR, and DORIS across a global multi-technique network. It provides the stable three-dimensional coordinate system upon which satellite navigation, Earth observation, sea-level monitoring, and all other geodetic applications depend. The ITRF is produced by the ITRS Product Center at IGN (France) using the CATREF software suite under the governance of the IERS Directing Board.
The supply chain is structured across five tiers. The critical bottleneck is Tier 3 — ITRS Combination at IGN — which carries the highest ITRF tier risk score (13.75) due to acute key-person risk concentrated around a small team at IGN operating proprietary software with no formal backup mandate and no documented succession plan for the combination process itself.
Tier Risk Score Summary:
| Tier | PPTD Gap | Step Criticality | Risk Score | Classification |
|---|---|---|---|---|
| Tier 0 — Multi-Technique Acquisition | 2.07 | 3 | 6.21 | Minor |
| Tier 1 — Global Archiving | 3.00 | 4 | 12.00 | Significant |
| Tier 2 — Technique Services | 2.13 | 4 | 8.50 | Significant |
| Tier 3 — ITRS Combination (IGN) | 2.75 | 5 | 13.75 | High |
| Tier 4 — Validation & Distribution | 2.50 | 2 | 5.00 | Minor |
(UN-GGCE Supply Chain Risk Assessment, 2026)
Key Finding: Tier 3 (ITRS Combination at IGN) is the highest-risk tier in the ITRF pipeline (score: 13.75, High), driven by acute key-person concentration in the IGN team and the proprietary CATREF software with no independent community implementation. Neither DGFI-TUM nor JPL holds a formal operational mandate to substitute for IGN — they are validators, not backups. On the governance track this tier records gaps against Principles 2 and 3, and its capability maturity sits below the Principle 5 minimum standard. Additionally, Tier 1 (Global Archiving) records a Significant score of 12.00 (Step Criticality raised to 4), reflecting both that the GDC network spans only two political jurisdictions (USA, France) — a governance-track gap against Principle 2 — and that the CDDIS/IGN/SIO equalization protocol, while architecturally real, has no documented test or use during any of the three known CDDIS-affecting disruptions; BKG has separately reported having no disaster-recovery capability of its own. No independent performance monitoring of the archiving function exists (Principle 6).
5. Earth Orientation Parameters (EGV Level 3)
Workflow document: EOP Workflow (Work Assignment 2 Annex, v3.5)
The EOP supply chain produces the fundamental transformation parameters linking the International Terrestrial Reference System (ITRS) to the International Celestial Reference System (ICRS). Four sub-products — Celestial Pole Offset (CPO), Universal Time (UT1), Length of Day (LOD), and Polar Motion (PM) — are delivered on two product tracks: a rapid daily series (Bulletin A, USNO) for space operations, and a monthly final series (Bulletin B / IERS C04, SYRTE) for geodetic combination. The EOP pipeline is structurally dependent on VLBI as the sole technique capable of determining UT1 — there is no observational alternative. This single-technique dependency is the defining risk of the EOP pipeline.
The supply chain is structured across five tiers. Tier 3 (EOP Combination) carries the highest EOP tier risk score (12.75), with Tier 1 (Global Archiving and Correlation) a close second (12.00) — reflecting, respectively, the governance exposure of the combination function and a VLBI correlation bottleneck at a single critical junction that directly affects the latency of the Rapid Service product on which space operations depend.
Tier Risk Score Summary:
| Tier | PPTD Gap | Step Criticality | Risk Score | Classification |
|---|---|---|---|---|
| Tier 0 — Multi-Technique Acquisition | 1.92 | 4 | 7.67 | Significant |
| Tier 1 — Archiving & Correlation | 3.00 | 4 | 12.00 | Significant |
| Tier 2 — Technique Analysis Centres | 2.69 | 4 | 10.75 | Significant |
| Tier 3 — EOP Combination | 3.19 | 4 | 12.75 | Significant |
| Tier 4 — Validation & Distribution | 3.38 | 2 | 6.75 | Minor |
(UN-GGCE Supply Chain Risk Assessment, 2026)
Key Finding: Tier 3 (EOP Combination) is the highest-risk tier in the EOP pipeline (score: 12.75). The USNO Rapid Service operates on a best-effort basis with no formal SLA and is subject to U.S. federal appropriations risk — governance-track gaps against Principles 3 and 6. Tier 1 (Archiving and Correlation, score: 12.00) is a closely ranked second, driven by the combination of a VLBI correlation throughput bottleneck at a small number of globally available facilities and the absence of geographic redundancy in the VLBI data archiving infrastructure; a failure at either the Washington or Bonn correlators would directly halt rapid UT1 production with no viable alternative, compromising the Bulletin A product that space operations globally depend upon (governance-track gaps against Principles 2 and 3). No EOP tier reaches the High band under the operational scoring, but the single-technique VLBI dependency for UT1 means the pipeline's structural exposure remains among the most acute in the assessment — the numeric scores should be read together with the governance-track findings.
6. International Celestial Reference Frame (EGV Level 3)
Workflow document: ICRF Workflow (Work Assignment 2 Annex, v3.5)
The ICRF is the quasi-inertial celestial reference frame defined by the precise positions of extragalactic radio sources (quasars), providing the inertial backdrop against which the ITRF is oriented and EOP are determined. The current realisation, ICRF3, was adopted by the IAU in 2018. Unlike other EGV products, the ICRF is an episodically produced scientific catalogue rather than a continuously updated operational product — it is reissued approximately once per decade. VLBI is the sole observational technique for ICRF maintenance; no redundant observational pathway exists.
The supply chain is structured across five tiers. Tier 1 (Archiving and Correlation) carries the highest ICRF tier risk score (15.00) — the second-highest across all five EGV workflows — reflecting the severe correlator throughput bottleneck and single-archive concentration at CDDIS.
Tier Risk Score Summary:
| Tier | PPTD Gap | Step Criticality | Risk Score | Classification |
|---|---|---|---|---|
| Tier 0 — VLBI Network Acquisition | 2.33 | 5 | 11.67 | Significant |
| Tier 1 — Archiving & Correlation | 3.00 | 5 | 15.00 | High |
| Tier 2 — IVS Analysis Centres | 3.31 | 3 | 9.94 | Significant |
| Tier 3 — ICRS Combination | 2.08 | 4 | 8.33 | Significant |
| Tier 4 — Validation & Designation | 2.33 | 1 | 2.33 | Minor |
(UN-GGCE Supply Chain Risk Assessment, 2026)
Key Finding: Tier 1 (Archiving and Correlation) is the highest-risk tier in the ICRF pipeline (score: 15.00, High), reflecting that the global inventory of VLBI correlation capacity is critically low — there are fewer than ten active IVS-affiliated correlators globally, and a failure at a major facility (Washington, Bonn, or Haystack) would halt processing for all sessions scheduled through that facility with no rapid fallback. The Step Criticality of 5 reflects that this is a global single point of failure with no alternative processing pathway. On the governance track this tier records gaps against Principles 2, 3, and 4. Tier 0 (score: 11.67, Significant) also carries Step Criticality 5, driven by the single-technique VLBI dependency and the sparse southern hemisphere network, with gaps against Principles 1 and 2.
7. Global Earth Gravity Field (EGV Level 3)
Workflow document: Global Gravity Model Workflow (Work Assignment 2 Annex, v3.3)
The Global Earth Gravity Field supply chain produces Global Gravity Field Models (GGM) — mathematical representations of the Earth's gravitational potential as spherical harmonic series. These models define the geoid, the physical reference surface for all global height measurements, and are the prerequisite for unified global height systems under UN General Assembly Resolution 69/266. The supply chain bifurcates between satellite gravimetry (GRACE-FO, GOCE) providing long-wavelength global coverage and surface gravimetry providing high-resolution short-wavelength detail. Both streams must be combined to produce operational models. The absence of a confirmed successor to GRACE-FO represents a mission-continuity risk that, if realised, would degrade time-variable gravity monitoring for all downstream EGVs including Terrestrial Water Storage and Ice Sheets.
The supply chain is structured across five tiers. Tier 2 (Gravity Data Processing and Analysis) carries the highest Gravity tier risk score (12.00), with Tier 3 (Geoid Model Development) close behind (11.50) — together reflecting the critically small pool of professionals capable of gravity processing and geoid model development and the institutional concentration of ultra-high-degree combination capacity.
Tier Risk Score Summary:
| Tier | PPTD Gap | Step Criticality | Risk Score | Classification |
|---|---|---|---|---|
| Tier 0 — Gravity Data Acquisition | 2.25 | 4 | 9.00 | Significant |
| Tier 1 — Data Archiving | 2.75 | 2 | 5.50 | Minor |
| Tier 2 — Processing & Analysis | 3.00 | 4 | 12.00 | Significant |
| Tier 3 — Geoid Model Development | 2.88 | 4 | 11.50 | Significant |
| Tier 4 — Validation & Distribution | 2.50 | 2 | 5.00 | Minor |
(UN-GGCE Supply Chain Risk Assessment, 2026)
Key Finding: Tier 2 (Processing and Analysis, score: 12.00) and Tier 3 (Geoid Model Development, score: 11.50) are the two highest-risk tiers in the Gravity pipeline and are best read as a single human-capital concern. The Training and Education capability (avg 1.70 — Phase 1 Priority) and Knowledge Management capability (avg 1.30) together create a structural succession risk: the global pool of professionals capable of producing next-generation ultra-high-degree gravity models is contracting through retirements with no documented replacement pipeline. No institution other than NGA, GFZ, and TU Munich currently possesses the capability to lead a successor to EGM2008, and even this concentration is inadequately documented — governance-track gaps against Principles 3 and 6, with capability maturity below the Principle 5 minimum standard. Tier 0 also records a Significant score (9.00), reflecting the GRACE-FO mission-continuity gap that has no formalised successor arrangement (a Principle 4 gap at the data acquisition tier).
8. Consolidated Capability Gap Table
The following table presents all capabilities that appear in the five assessed EGV workflow pipelines, sorted by average maturity score ascending. Scores are drawn from the published State of Geodesy 2026[^sog2026], verified 15 June 2026 against the published report; the workflows in which each capability appears are drawn from the Work Assignment 2 workflow topology analysis.
(State of Geodesy 2026)
| Capability | People | Process | Technology | Data | Avg | Appears in |
|---|---|---|---|---|---|---|
| Risk Management | 1.00 | 1.00 | 0.00 | 0.00 | 1.00 ⚠ | Satellite Orbits (T3), EOP (T3) |
| Knowledge Management | 1.00 | 2.00 | 1.00 | 1.00 | 1.30 ⚠ | Satellite Orbits (T2, T3), ITRF (T3), EOP (T2), ICRF (T2), Gravity (T3) |
| Research and Development Planning | 2.00 | 1.00 | 2.00 | 1.00 | 1.50 ⚠ | Gravity (T3) |
| Disaster Recovery and Supply Chain Continuity | 2.00 | 2.00 | 1.00 | 0.00 | 1.70 ⚠ | Satellite Orbits (T3), EOP (T4) |
| Training and Education | 2.00 | 1.00 | 2.00 | — | 1.70 ⚠ | ICRF (T2), Gravity (T2) |
| Data Distribution | 2.00 | 2.00 | 1.00 | 3.00 | 2.00 ⚠ | Satellite Orbits (T4), ITRF (T4), EOP (T4), Gravity (T4) |
| Geodetic Services | 2.00 | 2.00 | 2.00 | 2.00 | 2.00 ⚠ | Satellite Orbits (T4), ITRF (T4), EOP (T4), ICRF (T4), Gravity (T4) |
| Geodetic Software and Tools | 2.00 | 3.00 | 1.00 | 2.00 | 2.00 ⚠ | Satellite Orbits (T2), ITRF (T2), EOP (T2), ICRF (T2), Gravity (T2) |
| Data Quality Management | 2.00 | 2.00 | 1.00 | 3.00 | 2.00 ⚠ | Satellite Orbits (T1), ITRF (T1), EOP (T1), ICRF (T1), Gravity (T1) |
| Metadata Management | 2.00 | 2.00 | 1.00 | 3.00 | 2.00 ⚠ | Satellite Orbits (T1), ITRF (T1), EOP (T1), Gravity (T1) |
| Network Operations | 2.00 | 2.00 | 1.00 | 3.00 | 2.00 ⚠ | Satellite Orbits (T1), ITRF (T1), EOP (T1), ICRF (T1) |
| Data Preservation | 2.00 | 2.00 | 2.00 | 2.00 | 2.00 ⚠ | Satellite Orbits (T1), ITRF (T1), EOP (T1), ICRF (T1), Gravity (T1) |
| Performance Management | 2.00 | 2.00 | 0.00 | 0.00 | 2.00 ⚠ | Satellite Orbits (T3), EOP (T3) |
| Local Tie Processing and Analysis | 2.00 | 3.00 | 1.00 | 2.00 | 2.00 ⚠ | ITRF (T2, T3) |
| Local Tie | 2.00 | 2.00 | 1.00 | 3.00 | 2.00 ⚠ | ITRF (T0) |
| VLBI Data Processing and Analysis | 2.00 | 2.00 | 2.00 | 3.00 | 2.30 ⚠ | ITRF (T2), EOP (T2), ICRF (T2) |
| Ground-Based Asset Management | 3.00 | 2.00 | 2.00 | 3.00 | 2.50 ⚠ | Satellite Orbits (T0), ITRF (T0), EOP (T0), ICRF (T0), Gravity (T0) |
| Geodetic Data Products | 2.00 | 3.00 | 3.00 | 3.00 | 2.80 ⚠ | Satellite Orbits (T3), ITRF (T3), EOP (T3), ICRF (T3), Gravity (T3) |
| Gravity Data Processing and Analysis | 3.00 | 3.00 | 2.00 | 3.00 | 2.80 ⚠ | Gravity (T2) |
| Data Sharing | 3.00 | 4.00 | 2.00 | 3.00 | 3.00 | Gravity (T1, T4) |
| Reference Frames | 3.00 | 3.00 | 3.00 | 3.00 | 3.00 | ITRF (T3), EOP (T3), ICRF (T3) |
| Research and Development Prototyping | 3.00 | 3.00 | 3.00 | 3.00 | 3.00 | ICRF (T3), Gravity (T3) |
| Regulatory Compliance | 3.00 | 3.00 | 3.00 | 3.00 | 3.00 | Satellite Orbits (T4), ITRF (T4), ICRF (T4) |
| Standards Development and Promotion | 3.00 | 3.00 | 3.00 | 3.00 | 3.00 | Satellite Orbits (T4), ICRF (T4) |
| SLR Data Acquisition and Storage | 2.00 | 4.00 | 3.00 | 3.00 | 3.00 | Satellite Orbits (T0), ITRF (T0), EOP (T0) |
| VLBI Data Acquisition and Storage | 3.00 | 3.00 | 3.00 | 3.00 | 3.00 | ITRF (T0), EOP (T0), ICRF (T0) |
| Equipment Calibration and Maintenance | 4.00 | 3.00 | 3.00 | — | 3.30 | Satellite Orbits (T0), ITRF (T0), EOP (T0), ICRF (T0), Gravity (T0) |
| Gravity Data Acquisition and Storage | 2.00 | 4.00 | 4.00 | 3.00 | 3.30 | Gravity (T0) |
| GNSS Data Acquisition and Storage | 4.00 | 4.00 | 3.00 | 3.00 | 3.50 | Satellite Orbits (T0), ITRF (T0), EOP (T0) |
| SLR Data Processing and Analysis | 3.00 | 4.00 | 3.00 | 4.00 | 3.50 | ITRF (T2) |
| GNSS Data Processing and Analysis | 4.00 | 4.00 | 3.00 | 4.00 | 3.80 | Satellite Orbits (T2), ITRF (T2), EOP (T2) |
| DORIS Data Processing and Analysis | 4.00 | 4.00 | 3.00 | 4.00 | 3.80 | ITRF (T2) |
| DORIS Data Acquisition and Storage | 4.00 | 4.00 | 4.00 | 4.00 | 4.00 | Satellite Orbits (T0), ITRF (T0), EOP (T0) |
Score conventions: A score of 0.00 indicates a dimension the State of Geodesy 2026 assessment found not applicable to that capability, scored as 0 per the rubric Part A convention (NA = 0); a dash (—) indicates a dimension absent from the assessment record. Data Distribution, previously unscored, was scored in the June 2026 re-verification of the capability scores at an average of 2.00, closing the Tier 4 baseline gap identified in earlier versions of this report.
9. Cross-Workflow Investment Priority Ranking
The following table presents the top-10 tier risk scores across all five EGV workflows, sorted by score descending. This ranking constitutes the primary investment sequencing recommendation from the WA2 analysis. All scores are drawn from the UN-GGCE Supply Chain Risk Assessment (2026).
(UN-GGCE Supply Chain Risk Assessment, 2026)
| Rank | Workflow | Tier | PPTD Gap | Criticality | Score | Classification |
|---|---|---|---|---|---|---|
| 1 | Satellite Orbits | Tier 3 — ACC/SPOCC Combination | 3.65 | 5 | 18.25 | High |
| 2 | ICRF | Tier 1 — Archiving & Correlation | 3.00 | 5 | 15.00 | High |
| 3 | ITRF | Tier 3 — ITRS Combination (IGN) | 2.75 | 5 | 13.75 | High |
| 4 | EOP | Tier 3 — EOP Combination | 3.19 | 4 | 12.75 | Significant |
| 5 | EOP | Tier 1 — Archiving & Correlation | 3.00 | 4 | 12.00 | Significant |
| 6 | Gravity | Tier 2 — Processing & Analysis | 3.00 | 4 | 12.00 | Significant |
| 7 | ITRF | Tier 1 — Global Archiving | 3.00 | 4 | 12.00 | Significant |
| 8 | ICRF | Tier 0 — VLBI Network Acquisition | 2.33 | 5 | 11.67 | Significant |
| 9 | Gravity | Tier 3 — Geoid Model Development | 2.88 | 4 | 11.50 | Significant |
| 10 | Satellite Orbits | Tier 1 — Data Centres | 2.70 | 4 | 10.80 | Significant |
Ranks 5, 6, and 7 are tied at 12.00 with identical factor values. EOP Tier 1 is listed first because its deficit compounds the cross-workflow VLBI correlation dependency shared with ranks 2 and 8. ITRF Tier 1 is listed last because its deficit compounds the cross-workflow GDC archiving redundancy gap shared with rank 10 (Satellite Orbits Tier 1) — both tiers rest on the same CDDIS/IGN/SIO equalization protocol, which has no documented test or use during any of the three known CDDIS-affecting disruptions. EOP Tier 2 (10.75) and ICRF Tier 2 (9.94), previously ranked 9th and 10th, fall outside the top 10 under this revision.
Summary Observations
Satellite Orbits Tier 3 carries the highest risk score in the global geodesy supply chain. At 18.25, the ACC/SPOCC Combination tier leads the ranking by a clear margin (the next-ranked tier scores 15.00). No tier reaches the Critical band (≥ 20) under the operational scoring — but the governance track sharpens the picture: this is the only tier in the assessment with gaps against all four governance-track principles (2, 3, 4, and 6) simultaneously, and under the rubric such findings elevate a High operational score to urgent. Remediation requires a formalised multilateral ACC backup protocol, community access to the SPOCC combination software, and an SLA governing the function itself.
The three High tiers are precisely the three confirmed global single points of failure. Ranks 1, 2, and 3 — Satellite Orbits Tier 3, ICRF Tier 1, and ITRF Tier 3 — are the only tiers to reach the High classification, and all three carry a Step Criticality of 5 with no governed backup pathway. These three tiers collectively underpin the accuracy of every Level 3 EGV. Remediation of the governance gaps at these tiers (specifically: a formalised ACC backup protocol; a multilateral VLBI correlator capacity agreement; and succession and software documentation at the IGN ITRS Product Center) would reduce the supply chain's most severe exposures significantly.
Governance exposure concentrates where the numbers alone understate it. The EOP Combination tier (rank 4, 12.75) sits just below the High band, but its governance profile — no formal SLA, no independent monitoring, and direct exposure to U.S. federal appropriations risk (Principles 3 and 6) — mirrors that of the top-ranked tiers. As Part D of the Investment Prioritization and Risk Rubric directs, policy makers should read the operational score and the governance-track findings together before prioritising investment; a Significant score with severe governance gaps can warrant earlier action than a higher score with sound governance.
VLBI infrastructure requires coordinated investment across three workflows. Ranks 2 (ICRF Tier 1), 5 (EOP Tier 1), and 8 (ICRF Tier 0) all relate to VLBI infrastructure gaps. The underlying capability deficits — Network Operations (avg 2.00), Data Preservation (avg 2.00), and VLBI Data Processing and Analysis (avg 2.30) — appear in the same form across all three VLBI-dependent workflows (ICRF, EOP, ITRF), confirming that investment in VLBI correlator capacity would simultaneously address risk across multiple EGV products.
GDC archiving redundancy is architecturally real but operationally unverified, across two workflows. ITRF Tier 1 (rank 7, 12.00) and Satellite Orbits Tier 1 (rank 10, 10.80) both rest on the same CDDIS/IGN/SIO equalization protocol. This protocol is designed to let Analysis Centres draw identical data from IGN or SIO if CDDIS becomes unavailable, and has been invoked at least once (a 2007 hardware fault). However, no failover drill, disaster-recovery exercise, or documented instance of an Analysis Centre switching from CDDIS to IGN or SIO was found across any of the three confirmed CDDIS-affecting disruptions in this assessment (2013, 2018–2019, 2025); BKG has separately and openly reported having no disaster-recovery capability of its own. Step Criticality for both tiers has been raised from 3 to 4 to reflect that this redundancy has not been demonstrated under stress, though it stops short of the maximum Step Criticality of 5 reserved for tiers with no alternative pathway at all. The remediation is straightforward and low-cost relative to other findings in this report: a scheduled, documented failover exercise, repeated periodically, would convert this from an unverified assumption into a demonstrated capability.
Human capital is the defining supply chain risk. Five of the ten highest-risk tiers — Satellite Orbits Tier 3, ITRF Tier 3, EOP Tier 3, Gravity Tier 2, and Gravity Tier 3 — have Knowledge Management (avg 1.30), Training and Education (avg 1.70), or Risk Management (avg 1.00) as a contributing driver. Risk Management and Training and Education are Phase 1 Priority in the investment rubric; Knowledge Management is Phase 2. No technical remediation at the infrastructure or software layer can compensate for the absence of documented succession plans and trained replacement personnel. (Principle 5: Minimum Capability Maturity Standards) requires that this be addressed as a governance precondition for critical-path designation, not deferred to future investment phases.
Data Distribution is now scored, and confirms a Tier 4 technology gap. The Data Distribution capability — previously unscored, and flagged in earlier versions of this report as a baseline assessment gap — was scored in the June 2026 re-verification of the capability scores at an average of 2.00, with a Technology dimension score of 1.00. This closes the Tier 4 baseline gap and confirms that the distribution endpoints of four workflows (Satellite Orbits, ITRF, EOP, Gravity) rest on ageing, minimally maintained delivery infrastructure. Complete Tier 4 governance characterisation under (Principle 6: Transparency and Performance Accountability) can now proceed in WA3 from a full quantitative baseline.
End of Work Assignment 2 Report
[^sog2026]: United Nations Global Geodetic Centre of Excellence, 2026, State of Geodesy 2026: A Baseline Maturity Assessment, Bonn, Germany, https://www.un.org/globalgeospatial/sites/default/files/2026-05/stateofgeodesy.pdf [^igif]: UN-GGIM, Integrated Geospatial Information Framework (IGIF), https://ggim.un.org/UN-IGIF/ [^wmo]: World Meteorological Organization, 2021, Unified Data Policy (Resolution 1, Cg-Ext 2021), https://library.wmo.int/records/item/58166 [^sendai]: UNDRR, 2015, Sendai Framework for Disaster Risk Reduction 2015--2030, https://www.undrr.org/implementing-sendai-framework/what-sendai-framework [^igsmail]: International GNSS Service, 2013, IGSMAIL-6826, https://lists.igs.org/pipermail/igsmail/2013/000660.html [^igs2018]: International GNSS Service, IGS 2018 Technical Report, https://files.igs.org/pub/resource/technical_reports/2018_techreport.pdf