Measure altitude from the reference spheroid
03Altitude is height relative to the WGS84 reference spheroid, a mathematical Earth model used by GPS. The stored integer uses centimeters and an offset.
Separate height−100000.01 m would require a negative unsigned word. The bounded teaching encoder rejects it before writing a record; no wire-level error response is specified here.
Source for this drawing: RFC 1876 · Read RFC section 2 ↗
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“Updates” changes part of an earlier RFC. “Obsoletes” replaces it. This list shows selected related documents.
Add 10000000 centimeters to the signed height relative to WGS84; this places the zero encoded value 100000 meters below that reference.
- Add 10000000 centimeters to the signed height relative to WGS84; this places the zero encoded value 100000 meters below that reference.
- The master-file range is−100000.00 to 42849672.95 meters in steps of 0.01 meter. The upper endpoint fits the unsigned 32-bit field.
- Sea level is only an approximation to this reference. Altitude and/or vertical precision need adjustment where the two differ; this guide performs no geoid conversion.
Examples are fictional, offline teaching fixtures. RFC1876 is Experimental; its classful IPv4 fallback is historical, not universal current geolocation. Follow the linked official sections for full requirements.
Read the RFC section ↗