Transcript Slide 1

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.
Data items / Base Data
with associated spatial
extents (points, lines,
polygons, multi-points,
etc.)
C-squares workflow options
Non c-squares
mapper (s) – e.g.
Google Earth,
WMS, others...
Point data encoder
Line data encoder
Polygon data encoder
c-squares
encoding
Manual (GUI) data encoder
spatial
indexing
C-squares
decoder ( ->
GML, KML, other)
on-the-fly
mapping
Desktop GIS
Spatial Index
(stored list of c-squares
for every data item)
C-squares
mapper
(decoder built
in)
mapping from the
spatial index
Spatial query interface
Spatial search result
data “footprints”
export / import
item retrieval
request
data request
(spatial
subset)
Clickable map - can function
as new spatial query interface
Data extract
http://www.marine.csiro.au/csquares/