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Engineering reference

Surveying & Site: theory, method, and sources

This civil & structural engineering workspace publishes 9 governing equations, 5 stated assumptions, 1 documented boundary, and 2 sources so the numbers it returns can be checked rather than taken on trust.

Calculations run locallyCalculation & source methodology

How this tool works

Eleven modules cover coordinate geometry, traverse closure, differential levelling, horizontal and vertical curve layout, area and earthwork volume, and grading checks.

Traverse and point lists are entered as text and parsed, so a field book of legs or coordinates can be pasted in directly and the closure error and precision ratio read back.

Calculators and topics covered

  • surveying
  • site development
  • coordinates
  • curves
  • earthwork
  • bearing
  • azimuth
  • traverse closure
  • leveling
  • horizontal curve
  • vertical curve
  • shoelace area
  • stationing

Core equations

inverse:d=ΔE2+ΔN2,  bearing=atan2(ΔE,  ΔN)\text{inverse:}\quad d = \sqrt{\Delta E^{2} + \Delta N^{2}},\; \text{bearing} = \operatorname{atan2} \left(\Delta E,\; \Delta N\right)forward:E2=E1+d  sin(β),  N2=N1+d  cos(β)\text{forward:}\quad E_{2} = E_{1} + d\; \sin \left(\beta \right),\; N_{2} = N_{1} + d\; \cos \left(\beta \right)traverse closure:e=ΔE2+ΔN2,  precision=perimetere\text{traverse closure:}\quad e = \sqrt{\sum \Delta E^{2} + \sum \Delta N^{2}},\; \text{precision} = \frac{\text{perimeter}}{e}differential levelling:elevation=start+BSFS\text{differential levelling:}\quad \text{elevation} = \text{start} + \sum BS - \sum FSgrade:G=riserun×100%\text{grade:}\quad G = \frac{\text{rise}}{run} \times 100 \%circular curve:T=R  tan(Δ2),  L=RΔπ180,  M=R[1cos(Δ2)]\text{circular curve:}\quad T = R\; \tan \left(\frac{\Delta }{2}\right),\; L = \frac{R\Delta \pi }{180},\; M = R \left[1 - \cos \left(\frac{\Delta }{2}\right)\right]vertical curve:y=y0+g1x+(g2g1)x22L\text{vertical curve:}\quad y = y_{0} + g_{1} x \frac{+ \left(g_{2} - g_{1}\right) x^{2}}{2 L}polygon area (shoelace):A=12(xiyi+1xi+1yi)\text{polygon area (shoelace):}\quad A = \frac{1}{2} \left|\sum \left(x_{i} y_{i + 1} - x_{i + 1} y_{i}\right)\right|average end area volume:V=L(A1+A2)2\text{average end area volume:}\quad V = \frac{L \left(A_{1} + A_{2}\right)}{2}

Method and assumptions

Assumptions

  • Coordinates are plane rectangular; no geodetic projection, scale factor, or curvature correction is applied.
  • Bearings are measured clockwise from north in decimal degrees.
  • Levelling assumes balanced sight distances, so collimation and refraction errors are not corrected.
  • Traverse closure is reported only; no Compass Rule or Transit Rule adjustment is distributed.
  • Average end area volumes are approximate and overestimate on curved or rapidly changing sections, where the prismoidal formula is preferred.

Limitations and design boundaries

  • Educational coordinate and geometry tools only. They do not replace calibrated survey equipment, datum and projection handling, control adjustment, legal boundary analysis, or licensed surveying services.

Sources and references

Primary sources are preferred for ratings, standards, manufacturer data, and externally defined constants.

Source policy
  • Ghilani and Wolf, Elementary Surveying
  • Kavanagh, Surveying: Principles and Applications