Spectrum AtlasU.S. · 3 kHz – 300 GHz
Sources & methodology

What this atlas knows, and how

Every colored lane comes from one official, machine-readable table. Everything else is labeled as context, with its own citations.

Edition 2026-08-11

Regulatory data as of
2026-08-11 (NTIA Redbook web edition: “Updated: August 11, 2026”)
Coverage
Complete U.S. Table Federal and non-Federal columns, 0 Hz – 3,000 GHz in the data; the atlas shows 3 kHz – 300 GHz.
Records
1,044 jurisdiction blocks · 32 technology bands · 16 landmarks
Review status
Every row of the Federal and non-Federal columns in NTIA’s machine-readable Table of Frequency Allocations, 0 Hz to 3,000 GHz. Imported automatically and cross-checked at 33 boundaries against the FCC’s own table (data/fixtures/boundaries.json, an AI-assisted reading). A human review of representative ranges is still pending.
Audit notes
  • 1044 jurisdiction blocks imported from 612 source rows.
  • 3 referenced footnotes have no text in the footnote source: US265, US474D, US78.
  • federal: 501 blocks spanning 0–3000000000000 Hz, 0 gaps, 0 overlaps
  • non_federal: 543 blocks spanning 0–3000000000000 Hz, 0 gaps, 0 overlaps

Regulatory source

Fetched files

FileBytesSHA-256
TableOfAllocations.zip27,368c693f65225699d463bc5c8074a52bc3da5f321476b4c21272206d95706b3df2b
allocations.xml544,021c7def25f7db789307370a9fb025d419ae6c0d1267507b5d6b30ca1b027927247
allocations.xsd3,378192269bf653a456a5c40abbd9d3ab00fb403ef19941fb93fd457547abd87c04c
footnotes.html3,361,4800a7163be6f9137a5ef9f565618a00d8a9dd983a22fa3e90026323d27dc1da339

Method

  1. Acquire. 47 CFR § 2.106 is the regulatory text of record, but eCFR publishes the table itself as images. NTIA’s Redbook publishes the same U.S. Table as structured XML with a schema, so that is what we import. pnpm data:fetch downloads it with hashes.
  2. Normalize. pnpm data:build parses each row’s Federal, non-Federal and shared columns into half-open intervals in integer hertz, keeping exact service wording, primary/secondary status, footnotes and FCC rule parts. Unknown services or categories stop the build rather than being guessed. International (ITU Region) columns are not shown.
  3. Validate. pnpm data:validate rejects bad endpoints, unknown sources and duplicate IDs, and audits each jurisdiction column for gaps and overlaps. Both columns partition 0 Hz – 3 THz with no gaps or overlaps.
  4. Cross-check. 33 boundaries across all eight bands (VLF to EHF) were compared against the FCC’s own PDF table (an independent publication, revised July 2022). All match. Known differences: 3450-3700 MHz non-Federal: the July 2022 FCC PDF predates later rule changes reflected in NTIA's 2026 edition (3.45 GHz Service split at 3450/3600 MHz). Not used as a fixture. 1800-2000 kHz: the FCC PDF's column layout is ambiguous in text extraction, so it was excluded rather than guessed.
  5. Render. One scene graph draws the web chart (canvas) and the poster (SVG). Boundaries are never moved for looks; labels are dropped when they do not fit.

Reading the Table

Federal / non-Federal
The U.S. Table has two columns. Federal allocations are managed by NTIA for government users; non-Federal by the FCC for everyone else. Many bands are shared and appear identical in both.
Primary / secondary
Primary services are protected from harmful interference. Secondary services must not cause harmful interference to primary services and cannot claim protection from them. The Table prints primary services in capitals, as the atlas does.
Footnotes
5.xxx are international (ITU Radio Regulations); USxxx apply to both U.S. columns; NGxxx to non-Federal only; Gxxx to Federal only. They often change what a band permits; read them in the detail panel.

Curated layers

Technology bands (Wi-Fi, LTE and NR bands, GPS, broadcast services), landmarks and the radios in the Device X-ray are written by hand from the sources below. They are context, not allocations, and are marked provisional until independently reviewed. The Physics page uses textbook relations and cites the ITU-R recommendations they follow; its absorption curve is approximate. The sound on the Tune page is synthesized from the allocations, not recorded.

History timeline

The history page highlights the frequencies each turning point concerned on today’s Table. Its events are curated from the primary sources below and marked provisional.

The story’s world

The story is set in Wellfleet on Cape Cod, where Marconi’s South Wellfleet station stood. Its ground is real and baked by pnpm world:bake: elevation from the AWS Terrain Tiles (USGS 3DEP and NOAA data), and the coastline, ponds, marsh, woods, roads, railway and building footprints from © OpenStreetMap contributors (ODbL). When each building went up, most towers, the ships and the drawing are illustration. The station’s history follows the National Park Service.

Limits and disclaimer

Fonts: Instrument Serif, Geist and Geist Mono, SIL Open Font License 1.1. Government sources are public domain works of the U.S. Government.