What is the basis for the c-squares codes, and how easy is it to generate them from latitude/longitude data?
C-squares codes have been developed as an extension of an existing global grid, the WMO (World Meteorological Organization) 10 x 10 degree squares, a non-proprietary system for which maps can already be found on the internet (http://www.nodc.noaa.gov/OC5/wmoatlind.html and http://www.nodc.noaa.gov/OC5/wmopacific.html) and which is used (at that scale) to index substantial marine data holdings already (e.g., the NOAA “World Ocean Database”). The WMO grid was chosen because of its clearly defined relationship to principal lines of latitude and longitude at a 10 degree spacing (refer next question for the relevant detail). C-squares extends this notation by a hierarchical subdivision according to 2 sequences: a “main” sequence at 10 x 10, 1 x 1, 0.1 x 0.1 degrees, and an “intermediate” sequence at 5 x 5, 0.5 x 0.5, 0.05 x 0.05 degrees, etc. These two sequences are then “interwoven” to give the c-squares code for a square at any level of the hierarchy. It is possible to generate the c-squa
