Heimdall Research

Research

The evidence behind our work: what satellite imagery shows over time, what the public record looks like once it is gathered in one place, and the standards every figure we publish has to meet.

Evidence

What the data shows

Satellite imagery over time

The question
Many records describe places on the ground that nobody has visited in years, and the recorded locations are often off. Sending crews out is expensive, and imagery on its own won't tell you which feature matches which record.
What we measure
We compare satellite imagery against the records, so teams can see where conditions have changed and decide where to go first.
Satellite radar image of the Diomede Islands in the Bering Strait on 16 November 2024, surrounded by open water.

2024-11-16

The same area on 4 March 2025, with the islands surrounded by fractured pack ice.

2025-03-04

Diomede Islands, Bering Strait, 65.76°N 168.95°W. The same 48 by 27 km radar window, 108 days apart. Open water in November, pack ice by March. Contains modified Copernicus Sentinel data 2024, 2025.

The public record

The question
The record for a single federal decision is spread across many systems, and each one formats it differently. People planning around these decisions often end up relying on anecdotes or numbers they can't trace.
What we measure
We collect that record into one structured dataset, with each figure linked to the document it came from.
Where the record of one federal decision is published
StageWhere it is published
Public noticeFederal publication of record
Draft and final analysisNational document repository
DecisionLead agency files
ChallengeCourt and administrative filings

Standards

What every figure has to meet

These apply to client work and to everything we publish.

  1. Sourced

    Every number links to the document, record, or image it came from.

  2. Validated

    Results are checked against independent records, such as gauge readings or published surveys, and the comparison is kept.

  3. Uncertainty stated

    Figures carry a range and quality flags. A period with no usable data stays blank instead of being filled in.

  4. Versioned

    Each release has a version and a date, and older versions stay available.

  5. Corrected in public

    When we find an error, we fix it in a new version and record the change.

  6. Reviewed by a person

    Automated steps are checked by an analyst before anything is delivered or published.

Publications

Datasets and notes in preparation

  1. Dataset

    Western Terminal Lakes

    Monthly open-water area for six western lakes, with uncertainty ranges. Est. release December 2026.

  2. Dataset

    Exposed Lakebed and Surface State

    How much of each lakebed is exposed each month, and what surface covers it. Est. release December 2026.

  3. Dataset

    Arctic Navigable Window

    Open-water days each season at key Arctic passages. Est. release December 2026.

  4. Notes

    Research notes

    Short write-ups explaining each release and what it shows, published alongside the datasets.