CMAR c-squares Mapper - Technical Information

The CSIRO Marine and Atmospheric Research (CMAR) c-squares mapper is a perl utility which plots dataset exents on a range of base maps, selected automatically according to the extent of the dataset. It operates on "c-squares strings" as supplied by relevant data sources (e.g. metadata records). c-squares are units of the earth's surface divided up into 10, 5, 1, 0.5, or 0.1 degree squares (or smaller as desired), and are numbered according to a convention derived from the World Meteorological Organisation (WMO) 10-degree square numbers. c-square strings are text strings giving a list of relevant c-square numbers using a vertical bar ( | ) separator.

The c-squares mapper accepts the following inputs:

• csq - c-squares string, with no spaces - format example: 3416:237|3416:238|3415:132 etc. (1 degree squares) or 3416:238:4|3416:238:3|3415:132:2 etc. (0.5 degree squares)
• title - title for the map presented
• legend - text to be presented below the map, if desired
• color - a colour for the c-squares to be displayed on the map. Default is red if no colour is specified, otherwise choose from red, blue, yellow, black, brown, white, green - or enter a hexadecimal code (e.g. FF00FF) to specify a custom colour.

Advanced input options (new, April 2003):

• csq2 through csq7 - up to six more c-squares strings can be plotted on the same map, if desired.
• color2 through color7 - colours specified for multiple strings (if none supplied, a default series will be used).
• redirect - a web-accessible procedure on your own server which, if supplied as a value, will turn on the "active map" (= "click-on-a square") functionality so that, when the user clicks on a square, it will trigger the relevant spatial query back to your own system.

The c-squares map tester is a new web interface allowing user-defined input to any/all of these parameters for demonstration and testing purposes, with additional explanation on these features as required.

At present, the base maps used for the c-squares mapper cover the globe at low resolution, and the Australian region at higher resolution; the selection will be expanded over the next few months.