Basis-of-bearing rotation
Rotates deed or plat bearings to a new basis of bearing (like grid north) from one line whose bearing is known in both, and reports the rotation angle.
Experimental: not yet fully verified. How results are checked
Rotate every bearing by +0°02'30.0".
| Record | Rotated |
|---|---|
| S 80°00'00" E | S 79°57'30.0" E |
| N 45°30'00" W | N 45°27'30.0" W |
- Rotation
- Notice
Provenance
- Computed by
- survey.land.basis-rotation 1.0.0, core 0.1.0
- Model
- Rotation = new azimuth − record azimuth; each bearing's azimuth plus the rotation
- Accuracy
- Exact. The rotation is only as good as the common line's two bearings.
- Notes
- 1 shown with the answer
- Cites
- Ghilani, C. D., and Wolf, P. R., Pearson, Elementary Surveying: An Introduction to Geomatics; Robillard, W. G., and Wilson, D. A., Wiley, Brown's Boundary Control and Legal Principles
Something look off?
How we got thisFormula, worked example, sources, and proof
Model: Rotation = new azimuth − record azimuth; each bearing's azimuth plus the rotation
Accuracy: Exact. The rotation is only as good as the common line's two bearings.
Worked example: Record N 10°00'00" E is N 10°02'30" E on grid. Source: add-practitioner-essentials rotation scenario: every call rotates by +0°02'30".
You enter
- Bearings to rotate
- S 80°00'00" E N 45°30'00" W
- Same line on the new basis
- N 10°02'30" E
- Line's record bearing
- N 10°00'00" E
You get
- Rotation
- 0.041667°
- Rotation
- +0°02'30.0"
- Notice
- Parsing and arithmetic aid. Boundary determination requires a licensed surveyor and the governing records.
Review: Not yet independently reviewed by a licensed surveyor.
Last verified: 2026-09-18, when a maintainer last confirmed this tool's sources at the issuer. See the sources ledger.
Status: version 1.0.0, core 0.1.0. See this tool in the verification report.
Checked against: 5 golden test vectors (download the test vectors, each with its source and tolerance). See how results are checked and every source.
Sources
- Elementary Surveying: An Introduction to Geomatics, Ghilani, C. D., and Wolf, P. R., Pearson, 16th edition. Chapters 10 (traverse computations) and 12 (area by coordinates).
- Brown's Boundary Control and Legal Principles, Robillard, W. G., and Wilson, D. A., Wiley, 7th edition. Chapter 5 (metes-and-bounds descriptions, calls, and the order of importance of conflicting elements). Read free.
Experimental means this tool has not yet met the stable bar: at least 20 golden vectors, differential tests, and an independent worked example.