Represents the "PCSM" entry of the geospatial measure dictionary object.

It is an optional entry defined as part of the PDF 2.0 specification.

It contains an array which contains doubles, representing PDF numeric objects.

For definitive details see:.

Adobe Supplement to the ISO 32000, BaseVersion: 1.7, ExtensionLevel: 3; Table: 8.111a, page 50.

The ISO PDF Specification, ISO 32000-2:2017 PDF 2.0; Table: 269, page 599.

The projected coordinate system for measurement expresses distances in linear units rather than degrees, complementing the geographic coordinate system.