SRID, datum and accuracy

One authoritative reference

Every project carries an authoritative spatial reference — for example GDA2020 / MGA zone 56 (EPSG:28356). Assets created in that project inherit it. Display uses a web projection (EPSG:3857); the stored geometry is never changed to suit the map.

What is recorded

• geometry_srid — the reference the stored geometry is expressed in
• source_srid — the reference the data arrived in, from an editing client or an import file
• display_srid — the reference used for web display
• spatial_accuracy — the stated accuracy in metres

Rule of thumb

If a source file supplies eastings and northings, it must also state its CRS. With no CRS, Spatial7 will not guess: the values are kept for review and geometry is left unset until someone confirms the reference.