About Clarke

Clarke's table is the positions it can support from the UCS catalog, Space-Track TLEs, and FCC records. ITU filings are not in this product. This page does not state a count of ITU filings.

An FCC authorization and a satellite in the ±0.4° window are stored separately. A filing with no satellite in the window stays a paper filing. A satellite with no FCC row stays on station, unlicensed.

The UCS catalog and the Space-Track TLE can give different longitudes for the same satellite. Clarke occupies at the TLE when the quality gates pass, keeps the catalog longitude beside it, and flags a disagreement above 2°. A catalog longitude of 0, or a missing catalog longitude, is not a position and does not create a dispute.

476 positions, 469 on station. Positions are registry rows, one per slug. On station means at least one satellite in the ±0.4° occupancy window. The UCS snapshot has 590 GEO rows. 565 GEO satellites have an occupancy longitude, including station-kept payloads launched after that snapshot. The belt draws 532 TLE occupancy marks.

Occupancy clustering prefers a Space-Track TLE sub-satellite longitude when the TLE was fresh at ingest and passes GEO-payload quality gates (active payload, eccentricity, mean motion). UCS longitude remains the catalog value and is shown next to the TLE with a delta and a disputed flag when they differ by more than 2°. TLE longitude is not an FCC license location or ITU filing. The count of disagreements moves with each TLE ingest and is not a fixed registry total.

The UCS database includes NORAD catalog numbers and COSPAR international designators for each satellite. These identifiers are stored in Clarke's database but are not displayed to users. A spot-check of nine satellites against independent Celestrak records found that five had incorrect NORAD IDs, with some pointing to entirely different satellites at different orbital positions and one pointing to decayed re-entry debris. The satellite names, operator names, and orbital positions were generally accurate in the same check. Identifiers will be surfaced once they have been validated against an authoritative source.

The 167 FCC authorizations in Clarke cover US-licensed operators and foreign operators with FCC-granted US market access. Satellites licensed entirely under non-US administrations, including most European, Russian, Chinese, and Asian operators, do not appear in FCC records and will show no authorization data on their position pages. This is a reflection of jurisdiction, not a gap in data collection.

Position status labels in the registry (On station, Paper filing, On station unlicensed, Inactive) are derived from the UCS classification, which marks satellites as active based on reported operational status at the time of the snapshot. The UCS does not independently verify operational status in real time, and updates follow its twice-yearly cadence, so decommissions and new launches typically take up to six months to show up after they are publicly announced.

Viasat and SES both have current SEC financial data (Viasat through its most recent 10-Q, SES through its FY2025 20-F). Telesat's structured XBRL data caps at fiscal year 2021, the SEC's system has no more recent tagged financial facts for the entity on file, despite Telesat's ongoing 6-K filings since then. Treat Telesat's revenue and income figures as historical reference points, not current financials.

The registry's satellite layer comes from the UCS Satellite Database (see Data Sources above). This build has 7,551 UCS satellite rows across GEO, LEO, and MEO, of which 590 are GEO. 476 positions, 469 on station. Positions are registry rows, one per slug. On station means at least one satellite in the ±0.4° occupancy window. LEO and MEO stay out of the GEO registry table.

FCC authorization records from the Approved Space Station List are ingested as a second layer on top of the UCS satellite data. For each GEO position, Clarke queries the FCC table for any authorization within 0.6 degrees of the nominal longitude. Where a match exists, the detail page for that position shows the FCC call sign, licensee name, authorized frequency bands, administration, and in-orbit date. Where no match exists, the position has no US FCC authorization, which is expected for satellites licensed under non-US administrations.

Multiple satellites operating at the same nominal longitude are grouped together using a tolerance of 0.4 degrees on the occupancy longitude (Space-Track TLE when usable, otherwise UCS). This matches ITU co-location practice. The grouping is physical occupancy, not an FCC or ITU assignment: SES-1 stays at 101°W because its TLE agrees with UCS; MUOS-2, whose UCS row still says 100.1°W, occupies at its TLE near 172°E.

Congestion v0 is a labeled model on the Slot Terminal, not a recorded fact and not a registry column. It is a normalized 0 to 100 index blending three signals at a position: arc density (GEO satellites whose occupancy longitude is within 2 degrees), direct co-location (within 0.4 degrees), and contention (distinct operators). Occupancy longitude is TLE-primary, with the UCS catalog as fallback. Density contributes up to 50 points, co-location up to 30, and operator contention up to 20. A position packed by a single operator scores lower on contention than an equally dense arc contested by many operators, because multi-operator arcs carry a heavier interference-coordination burden. The tiers are Sparse for 0 to 14, Low for 15 to 34, Moderate for 35 to 54, High for 55 to 74, and Critical for 75 to 100. Scores reflect tracked hardware, not filed ITU positions, so they understate coordination pressure in arcs with heavy filing or squatting activity.

Each position carries a heuristic implied valuation, expressed as a range rather than a point figure because it is derived from public data, not transaction records. A $30M baseline is multiplied by arc desirability, a GDP/population coverage proxy by longitude band, occupancy (co-located satellites), remaining-life quality from UCS lifetime fields, operator tier, spectrum (when known), scarcity (congestion score), and FCC/license plus paper-vs-brought-into-use signals. Every factor and its multiplier is shown on the Slot Terminal (Pro) so the estimate can be inspected. Confidence is high for curated positions, medium for active positions with a known operator, and low for sparsely-attributed UCS-derived entries; the range widens as confidence falls. History is a seeded 30-day model path in data/terminal.db, not observed trades. This is an analytical model, not an appraisal, a quote, or investment advice.