Site Grid Coordinate Converter

Explicit local planar site grid similarity transform, not lat/lonprojection, geodesy or unexplained datum shift. Caller independently establishes sample/context/calibration applicability; not definitive chronology, provenance, taxonomy, disease or human identity.

Description

A local site grid can be scaled, rotated and translated into a shared planar frame.

A local site grid can be scaled, rotated and translated into a shared planar frame.^[1]

This transformation is distinct from geodetic projection or deriving survey-control parameters. Use Site Grid Coordinate Converter to evaluate the supplied inputs under the model explained below.

When to use Site Grid Coordinate Converter

Use Site Grid Coordinate Converter to evaluate the supplied inputs under the model explained below. Establish the units, measurement scope and model assumptions before entering values.

How to use Site Grid Coordinate Converter and understand its results

Establish the units, measurement scope and model assumptions before entering values.
Enter Local grid x y, Caller scale meters per grid unit, Caller counterclockwise rotation degrees, Caller planar translation meters using the field table and validation rules below, then run the tool.
Read Site planar coordinates meters; interpret the units, signs, ordering and unknown-value placeholders described below.
Correct reported input errors and rerun. Apply successful results according to their specific meanings and check the assumptions before using them in a decision.

Input field	Meaning	Value type	Requirement
localGridXY	Local grid x y	array of array	Required; constraints below
callerScaleMetersPerGridUnit	Caller scale meters per grid unit	number	Required; constraints below
callerCounterclockwiseRotationDegrees	Caller counterclockwise rotation degrees	number	Required; constraints below
callerPlanarTranslationMeters	Caller planar translation meters	array of number	Required; constraints below

Enter a nonempty matrix of finite local [x,y] coordinates, a positive scale in m/grid-unit, finite counterclockwise angle in degrees and exactly two translation coordinates in m. Scale the standard rotation and add translation to each point in order. No geodetic projection, transformation fit or control-point validation is supplied.

siteX=tx+k(xcosθ−ysinθ); siteY=ty+k(xsinθ+ycosθ)

Use the field order, units and branch conditions described above.

Output field	Meaning	Value type
sitePlanarCoordinatesMeters	Site planar coordinates meters	array of arrays

json

{
  "input": {
    "localGridXY": [
      [
        1,
        0
      ],
      [
        0,
        1
      ]
    ],
    "callerScaleMetersPerGridUnit": 2,
    "callerCounterclockwiseRotationDegrees": 90,
    "callerPlanarTranslationMeters": [
      10,
      20
    ]
  },
  "output": {
    "sitePlanarCoordinatesMeters": [
      [
        10,
        22
      ],
      [
        8,
        20
      ]
    ]
  }
}

Limitations and assumptions

This transformation is distinct from geodetic projection or deriving survey-control parameters. Apply the exact scope and assumptions explained above.

All listed fields require explicit values. Unexpected fields, incorrect types, nonfinite numbers and sparse arrays fail validation. Domain-specific bounds, alignments and supported tokens are explained above; extremely large inputs or outputs can also be rejected. Input errors differ from successful false results, empty match lists and unknown-evidence placeholders.

Alternative or Complementary methods

Use Site Size From Artifact Scatter Calculator for a related task: An artifact scatter's convex hull encloses its measured outer points.

Use Site Catchment Radius Walk-Time Calculator for a related task: A catchment radius can be estimated from a travel budget and effective walking speed.

References

Site Grid Coordinate Converter — tool.io

Similar or alternative tools

Site Size From Artifact Scatter Calculator
An artifact scatter's convex hull encloses its measured outer points.
Site Catchment Radius Walk-Time Calculator
A catchment radius can be estimated from a travel budget and effective walking speed.