C-squares concept: hierarchical text-based identifiers for global grid squares

Example 10x10 deg. square ID: 3414

Example 5x5 deg. square ID: 3414:1

Example 1x1 deg. square ID: 3414:100

Example 0.5x0.5 deg. square ID: 3414:100:1

(etc.)

Identifiers are meaningful, e.g. “3414” indicates the following:

-- global quadrant “3” (SE) – 3414

-- 40+ degrees of latitude (S) – 3414

-- 140+ degrees of longitude (E) – 3414

The spatial footprint of any data item can be represented as a list of the square IDs (c-square codes) that it intersects.

C-squares workflow optionsData items / Base Data with associated spatial extents (points, lines, polygons, multi-points,

etc.)

Spatial Index(stored list of c-squares

for every data item)

Point data encoder

Line data encoder

Polygon data encoder

Manual (GUI) data encoder

Spatial query interface

Spatial search result

Clickable map - can function as new spatial query interface

C-squares mapper

(decoder built in)

Non c-squares mapper (s) – e.g.

Google Earth, WMS, others...

C-squares decoder ( ->

GML, KML, other)spatial

indexing on-the-fly mapping

mapping from the spatial index

Data extract

data request (spatial subset)

c-squares encoding

http://www.marine.csiro.au/csquares/

item retrieval request

data “footprints” export / import

Desktop GIS