# Coordinate systems — reference vs working grid

> Two CRS settings, what each controls — and why your original coordinates are never touched.

Source: https://geodb.io/guide/topic/coordinate_systems/ · Category: Getting set up
geoDB has two coordinate-system settings, and they answer different
questions. Knowing which is which saves real confusion.

## The reference CRS — "what grid does my data arrive in?"

When you create a project you declare a **reference CRS**: the grid your
incoming coordinates are usually in — a UTM zone, a state plane, or plain
latitude/longitude. It's the default the import screens assume, and each
imported record also remembers the grid it was actually declared in, so
mixed-grid projects work fine.

## Your original coordinates are never touched

Import keeps your coordinate values **exactly as you entered them**, in the
grid you declared — for a UTM import that means an **easting and a
northing**. This is why your data tables label the columns **"Lon/Easting"**
and **"Lat/Northing"**: the pair carries whatever your declared grid uses,
and holds true degrees only when that grid is plain latitude/longitude
(WGS84). The converted WGS84 copy lives separately and is what maps and 3D
read. Nothing is overwritten, so there is nothing to "fix": if data was
imported with the wrong grid declared, re-import it with the right one —
never edit the coordinate values themselves.

## The working grid — "how should 3D and exports lay things out?"

The **coordinate-system page** (Project Settings → Coordinate System, or
step 3 of the setup wizard) sets the binding local grid: the projected CRS,
origin and rotation used for drill-hole desurveying, local coordinates, the
3D scene, and Blender/QGIS/Leapfrog exports. Three ways to set it:

- **Auto-calculate** — picks the right UTM zone from your data's location
  and a tidy southwest origin. Its "coordinate range" check reads point
  features (collars, samples); a project whose extent is polygons-only will
  honestly say it can't judge the range — the CRS and origin are still valid.
- **Manual entry** — choose the CRS with the searchable picker and set the
  origin and rotation yourself.
- **Mine grid calibration** — for historic data recorded in a pre-GPS local
  mine grid. Provide at least three control points known in both the mine
  grid and GPS, and geoDB computes the transformation; data imported as
  "Local Mine Grid" re-projects through it.

## Why skipping it bites

Setting the working grid also computes your project's **coverage bounds**.
Skip it and desurveying, local coordinates and 3D stop working — and the
elevation step can't run ("no coverage area defined") until you come back
to it, from the dashboard's setup card or project settings.