Ground Track / Orbital Period vs Altitude implementation

Binding contract

This record describes what an executable surface must bind and validate. It does not claim that a public calculator, package, or production route is deployed.

Record owner

Guth Instruments

Lifecycle

verified-clean

Evidence ID

t4-256

Effect

Computation or source lookup only

Input and validation requirements

A zero supplied period makes the orbits-per-day calculation undefined, and an unspecified altitude unit permits materially different outputs for the same numeric input.

Required corrections

No binding erratum is attached to this unique-name record. Implementers must still preserve the declared units, domain, and failure behavior.

Inspectable interface fixture

The sample below is evidence for interface and validation tests, not a production implementation.

{
  "inputs": {
    "altitude_km": 0,
    "mu_km3_s2": 398600.4418,
    "earth_radius_km": 6378.137
  },
  "expected_outputs": {
    "period_s": 5069.34,
    "orbits_per_day": 17.0436
  },
  "working": "a = Rₑ + h = 6378.137 + 0 = 6378.137 km. T = 2π√(a³/μ) = 2π√(6378.137³ / 398600.4418) ≈ 5069.34 s. Orbits/day = 86400 / 5069.34 ≈ 17.0436."
}

Other records

Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

• VERIFIED_LEDGER.json
• evidence-tranche4/tranche4-results.json