GCRI · 宇宙と地球観測
通信と航法
Satellite communications connect remote areas, ships, aircraft and disaster zones, and navigation satellites provide the position and timing that transport, telecom, finance and power grids depend on. Large new constellations are changing both. This page sets out how satellite communication and navigation services work, how society’s dependence on them can be mapped, and what evidence serves the regulators and operators who plan for their loss.
Communications and navigation on the record.
Communications and navigation: how the risk develops.
GNSS, satcom and dependency. The dossier below sets out how the risk develops, what is measured, where the data come from, how it is modelled and who decides.
Constellations change connectivity
Large low Earth orbit constellations offer lower latency broadband, extending coverage but concentrating it with a few operators.
Timing is a hidden dependency
Telecom networks, power grid measurement and financial システム use satellite time signals. Many users do not know they depend on them.
Navigation underpins transport
Aviation, shipping, road logistics and agriculture rely on satellite positioning, with augmentation systems for higher accuracy and integrity.
Backups are often missing
Alternative positioning and timing, such as terrestrial systems or holdover clocks, are unevenly deployed, so outages can cascade.
How communications and navigation is modelled, measured and tested.
モデル、その仮定、データ、不確実性を、科学者やエンジニアが確認する形で示します。構造は公表された手法に従っています。描かれた値は例示であり、知見ではありません。
地球観測の連鎖
How a satellite or sensor record becomes evidence on communications and navigation, and where each step adds uncertainty.
- 01・取得軌道、センサー、再訪頻度不確実性：雲と軌道による欠測
- 02・較正放射量的および幾何学的不確実性：センサードリフト
- 03・訂正大気と地形不確実性：エアロゾルと斜面の前提
- 04・検索または分類変数またはクラス不確実性：モデルと学習の誤差
- 05・検証実測値との照合不確実性：標本設計と標本サイズ
- 06・公開誤差範囲と系譜つき不確実性：明示し、隠さない
Satellite communication and navigation reach every domain.
Findings are designed for the 戦略システム・シリーズ. Spectrum is governed by the ITU Radio Regulations; the Global Centre for Risk and Innovation (GCRI) recommends no provider.
- Interference and outage records.
- Connectivity studies in remote areas.
何を、どの程度うまく測定しているか。
各指標には、その単位、更新頻度、背後にある出典の種類、値が持つことになるエビデンスのラベルが付いています。値は表示しません：プログラムが自らの権限のもとで値を提供します。
| 指標 | 単位 | 周期 | 出典の種類 | ラベル |
|---|---|---|---|---|
| Population covered by satellite broadband | percent of population | 年次 | Regulator and operator data | 推定 |
| Critical sectors using GNSS timing | count of sectors | 評価ごと | Dependency studies | 推定 |
| Timing holdover capability | hours | per system | Operator documentation | 申告済み |
| Satellite broadband subscribers | 件数 | 年次 | Regulator statistics | 公表統計 |
| Satellite-based augmentation coverage | status by region | 評価ごと | Augmentation system documentation | 公表統計 |
| Navigation outages and degradations | count and duration | 年次 | Service notices | 公表統計 |
エビデンスの出所。
名前の明示された公開データセットと機関の記録。それぞれにライセンス区分があります。合意に基づく出典は、その条件のもとでのみ使用し、再公開することはありません。
| 出典 | 提供するもの | ライセンス区分 |
|---|---|---|
| ITU satellite network filings and Radio Regulations | Spectrum and orbit filings | Public, ITU terms |
| GNSS service performance reports (GPS, Galileo, GLONASS, BeiDou) | Service performance and notices | Public, terms per provider |
| Government studies of GNSS dependence, such as the UK and US economic impact studies | Sectors depending on positioning and timing | Public records, licence per government |
| National telecom regulator statistics | Satellite broadband adoption | Public records, licence per regulator |
| ICAO and IMO documentation on navigation | Navigation requirements in aviation and shipping | Public, terms per organisation |
誰が決め、エビデンスが何に役立つか。
Space and Earth Observation prepares evidence. The decisions below are taken by the authorities named, under their own rules, and never by the platform.
| 誰が決定するか | 質問 | このページが提供するエビデンス |
|---|---|---|
| Telecom and transport regulators | What backup timing and navigation to require | Dependency maps; backup reviews |
| 重要インフラ operators | How long they can operate without satellite timing | Holdover evidence |
| Governments planning connectivity | Where satellite broadband fills gaps | Connectivity gap analyses |
このトピックが生み出す成果物
- Dependency maps of positioning and timing
- Backup capability reviews
- Connectivity gap analyses including satellite options
- Evidence notes for resilience planning
専門家が問うこと。
Specialists in navigation and satellite communications ask how dependent システム are and how they fail.
- Which sectors rely on satellite timing and positioning, and do they know it?
- How vulnerable are receivers to jamming, spoofing and interference?
- What alternative time and position sources exist, and are they in use?
- How do satellite communications support emergency response and remote areas, and how resilient are they?
- How does the growth of large communications constellations change dependency and risk?
Weak signals, wide dependence.
Navigation satellites broadcast signals that receivers use to calculate position and time. The signals are very weak by the time they reach the ground, which makes them easy to drown out with jamming or imitate with spoofing. Beyond navigation for transport and agriculture, the timing function is embedded in telecommunications networks, electricity grid synchronisation and the time-stamping of financial transactions, often without operators being aware of it.
Satellite communications carry data, voice and broadband to ships, aircraft, remote communities and disaster zones where terrestrial networks are absent or damaged. They are themselves exposed to interference, ground-segment faults and space weather. Resilience comes from diversity: multiple constellations, terrestrial backups, holdover clocks that maintain time during outages, and receivers that detect anomalies.
エビデンスがどのように築かれ、どこで止まるか。
- 01
Dependency surveys
Identifying where timing and positioning are used in critical services. Embedded dependencies are often undocumented.
- 02
Interference monitoring
Detecting jamming and spoofing through receiver networks and communications and network technology. Coverage of monitoring is limited.
- 03
レジリエンス・テスト
Testing how システム behave when signals are lost or falsified. Live testing is constrained by regulation and safety.
- 04
Signal and orbit physics
Modelling signal propagation and errors, grounded in 物理学. Atmospheric effects vary in ways that are hard to predict locally.
どのように研究され、手法が言えないことは何か。
Where this page’s references lead.
このページの読解の基準となる機関と文書。状態と版は変わります。各リンクは発行機関へ移動します。
質問と回答。
What is GNSS?
Why do power grids and banks depend on satellites?
What is a low Earth orbit constellation?
Why does finance depend on satellite navigation?
What is spoofing?
Are there alternatives to satellite timing?
このページからエビデンスを提供する。
報告書 is the Consortium’s quarterly publication. What you know about this subject can become evidence, a case or a correction in the next edition, credited to you and published under CC BY 4.0 where it is your own work.
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