Survey Loop Misclosure Error Calculator

Actual cave loop raw3Dvector closure from distance/azimuth/inclination shots, xEastyNorthzup. Independently matched angular/datum calibration required; closed-loop identity external, not adjusted survey quality or error attribution.

Description

A closed-loop survey ideally returns to its start in the adopted coordinate frame.

A closed-loop survey ideally returns to its start in the adopted coordinate frame.^[1]

The accumulated shot displacement gives a signed closure vector and its magnitude.

When to use Survey Loop Misclosure Error Calculator

Use this tool to obtain signedClosureMeters, observedClosureMagnitudeMeters, observedSurveyedLengthMeters from the supplied records using the stated calculation. Establish the survey or observation scope, reference frame, units and independently applicable calibration or qualified plan.

How to use Survey Loop Misclosure Error Calculator and understand its results

Establish the survey or observation scope, reference frame, units and independently applicable calibration or qualified plan.
Enter actualDistanceAzimuthInclinationShots, using the field meanings and rules below, then run the tool.
Read result.signedClosureMeters, result.observedClosureMagnitudeMeters, result.observedSurveyedLengthMeters. Use the units and sign conventions below, and review any unknown records separately.
Correct any reported input issue and run again. Before using a successful result, check the stated units, signs, reference scope and observation coverage.

Input field	Meaning	Value type	Requirement
actualDistanceAzimuthInclinationShots	Actual distance azimuth inclination shots	numeric matrix	Required

Supply a nonempty matrix of distance/azimuth/inclination triplets. Distances are nonnegative metres, azimuths in [0,360) degrees and inclinations in [−90,90] degrees. Sum east/north/up displacements, return their Euclidean norm and total surveyed length. A nonzero vector is retained; no loop adjustment is performed.

closure=Σ[d×cos(i)×sin(a),d×cos(i)×cos(a),d×sin(i)]; magnitude=norm(closure); length=Σd (radian angles)

Use the matching field units and the exact boundary, ordering and reference rules above.

Output field	Meaning	Value type
result	Qualified observed calculation or explicit reference	object
result.signedClosureMeters	Accumulated shot displacement ordered east/north/up in metres.	list
result.observedClosureMagnitudeMeters	Euclidean magnitude of the accumulated closure vector.	number
result.observedSurveyedLengthMeters	Sum of supplied shot distances in metres.	number

json

{
  "input": {
    "actualDistanceAzimuthInclinationShots": [
      [
        1,
        0,
        0
      ],
      [
        1,
        180,
        0
      ]
    ]
  },
  "output": {
    "result": {
      "signedClosureMeters": [
        1.2246467991473532e-16,
        0,
        0
      ],
      "observedClosureMagnitudeMeters": 1.2246467991473532e-16,
      "observedSurveyedLengthMeters": 2
    }
  }
}

Limitations and assumptions

The actual observation coverage, calibration and qualified plan determine applicability. A numerical result does not establish survey accuracy, route suitability, atmosphere conditions or equipment adequacy beyond the declared comparison.

Missing required fields, unknown fields, wrong types and violated rules return input issues. Numeric values and outputs must be finite. Lists and matrices must be dense, without missing cells. Numeric matrices allow at most 128 rows and 128 columns, subject to the narrower shape requirements above. Extremely large composite outputs are rejected.

Alternative or Complementary methods

For a related step, use Survey Shot 3D Coordinate Calculator: A cave survey shot relates a measured distance, azimuth and inclination to a Cartesian displacement. For a complementary comparison, use Extended Elevation Projection Length Calculator: Extended elevation unfolds a cave survey using independently assigned left and right directions.

References

Survey Loop Misclosure Error Calculator — tool.io

Similar or alternative tools

Survey Shot 3D Coordinate Calculator
A cave survey shot relates a measured distance, azimuth and inclination to a Cartesian displacement.
Extended Elevation Projection Length Calculator
Extended elevation unfolds a cave survey using independently assigned left and right directions.