Coordinate Format Converter (multi) mechanism

Model scope

The claimed multi-format conversion is standard in principle, but the provided formula description is insufficient to verify correctness. The exact unresolved ambiguity is the MGRS-to-decimal point convention and precision policy; additional unresolved behavior includes UTM zone-boundary/antimeridian handling, special Norway/Svalbard zones, input grammar, and datum declaration. Verdict is NEEDS_REVIEW until these are specified and implemented against authoritative WGS84/MGRS test data.

• The specification only says "chained coordinate transforms" and does not define the actual WGS84 geographic-to-UTM and UTM-to-geographic equations, longitude-zone rule, latitude-band rule, MGRS 100 km-square tables, or precision/truncation behavior.
• The implementation must distinguish UTM hemisphere from the MGRS latitude-band letter; these are not interchangeable labels.
• UTM requires zone selection as floor((longitude + 180) / 6) + 1, with the standard Norway and Svalbard zone exceptions if global coverage is claimed.
• MGRS conversion requires the correct zone-dependent easting-letter sequence and odd/even-zone northing-letter sequence, including omitted letters I and O.
• MGRS is a finite-precision grid reference, not an exact point. The specification does not state whether conversion to decimal uses the southwest corner, cell center, or an interval.
• The specification does not state whether longitude is normalized to [-180,180), how antimeridian coordinates are handled, or whether coordinates exactly on a UTM zone boundary use the eastern or western zone.

Units and conventions

• Decimal latitude and longitude are in degrees, not radians.
• DMS components are degrees, arcminutes, and arcseconds; 1 degree = 60 arcminutes and 1 arcminute = 60 arcseconds.
• Latitude is positive north and longitude is positive east; S and W hemisphere suffixes negate the corresponding signed value.
• UTM uses WGS84 ellipsoid parameters a = 6378137 m and inverse flattening 298.257223563, central scale factor k0 = 0.9996, false easting 500000 m, and false northing 0 m in the northern hemisphere or 10000000 m in the southern hemisphere.
• UTM easting and northing are in metres.
• The MGRS examples use 5 digits for easting and northing, giving 1 m nominal precision.

Inspectable vector

One of 4 source-bound review vectors:

{
  "inputs": {
    "format": "decimal",
    "latitude_deg": 40,
    "longitude_deg": -105
  },
  "expected_outputs": {
    "decimal": {
      "latitude_deg": 40,
      "longitude_deg": -105
    },
    "dms": "40°00'00.000\\\"N, 105°00'00.000\\\"W",
    "utm": {
      "zone": 13,
      "hemisphere": "N",
      "easting_m": 500000,
      "northing_m": 4427757.219
    },
    "mgrs": "13T EE 00000 27757"
  },
  "working": "DMS: 40 + 0/60 + 0/3600 = 40°N; -(105 + 0/60 + 0/3600) = -105°E. UTM zone = floor((-105 + 180)/6) + 1 = floor(12.5) + 1 = 13. Zone 13 central meridian = 6(13) - 183 = -105°. Therefore longitude difference is 0°, so the transverse-Mercator easting is the false easting 500000.000 m. Applying the WGS84 meridional-arc equation at latitude 40° gives northing 4427757.219 m. The 100 km easting square is E (500000 m), and the 4,400,000 m northing row in odd zone 13 is E; the 27,757 m remainder gives 27757. Hence MGRS = 13T EE 00000 27757."
}

Failure boundary

BREAK_CLAIMED · SELF_FLAGGED

The specification leaves zone-boundary ownership, UTM pole rejection, MGRS precision, and directional sign conventions unspecified. A converter that silently accepts the pole or interprets unsigned longitude differently can produce undefined or materially different outputs.

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-tranche6/tranche6-results.json
• BOUNDARY_HAZARD_CATALOG.json