Use this geodetic reference utility when the coordinate system and ellipsoid are explicitly identified and the requested parameter is needed for a larger coordinate calculation.

Realisation

WGS84 realisation; the semi-major axis is identical across realisations.

Return the WGS84 ellipsoid semi-major axis in metres for the requested realisation. The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

Semi-major axis (m)

Ellipsoid semi-major axis a in metres.

• An ellipsoid parameter alone does not define a complete datum or coordinate reference system. Epoch, frame realization, axis order, units, projection, and transformations affect coordinates.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Carry the full CRS identifier and use an authoritative transformation library when converting measured coordinates between frames.

• Scanning Resolution PPI by Original Type Lookup

  Return a recommended scanning resolution in pixels per inch for common archival original types; published guidance varies, so values are a heuristic lookup.

• Particle Board Density Lookup

  Classify a particle board by thickness and return its nominal raw density in kilograms per cubic meter.

• Return Migration Proportion Lookup

  Compute the proportion of in-migration to a place that consists of former residents moving back, as return migrants per hundred total in-migrants.