Hash %name_for_map_series

The keys are the single letter codes used for each map series. The values are the descriptive names of each series. Currently we have:

  A : OS Landranger
  B : OS Explorer
  C : OS One-Inch 7th series
  H : Harvey British Mountain Maps
  J : Harvey Superwalker

Hash %maps

The keys are short identifiers for each sheet or inset. Where a map has more than one side, or includes insets then, there will be a separate entry for each side and inset.

The value for each key is another hash containing the following items

bbox

The bounding box of the sheet as a list of two pairs of coordinates (in metres from the grid origin)

polygon

A list of pairs of coordinates (in metres from grid origin) that define the corners of the sheet. The list starts at the SW corner (approximately, some do not have an obvious place to start), and works round anticlockwise. In all cases the last pair is the same as the first pair.

area

The calculated area of the sheet in square kilometres.

series

A single letter series identifier -- this will be one of the keys from the "name_for_map_series" hash.

number

The identifier for this map within the series, not including any suffix for a sheet or an inset. The two sides of a single map have the same number. The number is not always an integer - Outdoor Leisure maps are designated "OL14" etc. Those maps known by two numbers have a "number" consisting of both numbers divided by a "/"; such as "418/OL60" in the Explorer series.

parent

The key of the parent map for an inset. Main sheets of a map will have "parent" equal to their own key.

title

The title of the map. Different sheets and insets from the same map will have the same title.