A "pyramid" of square tiles. Each level of the pyramid on the way down has four times as many tiles as the previous level.
When SIS draws an Index Overlay with a Pyramid namer, only one level of the pyramid will be drawn. For example, suppose that the bottom level of the pyramid has tiles of 1000m at 1:10000 scale, then the second level of the pyramid will have tiles of 2000m at 1:20000 scale. Now if you zoom in to an effective scale of 1:10000 then SIS will only draw tiles from the bottom level, but when you zoom out to 1:20000 then SIS will only draw tiles from the second level.
The properties of the Pyramid correspond to tiles on its bottom level (e.g. the smallest tiles).
Typical tile name: 0qNNNNNN.ext, where N is between 0 and 3 and specifies a pyramid level quadrant.
The tiles are in a cartesian Coordinate Reference System.
The tiles are in a spherical Coordinate Reference System.
The width and height of each tile, in metres or degrees for cartesian and spherical tiles respectively.
A named Coordinate Reference System stored in a Named Object Library (without quote characters).
The maximum number of digits in a file name, in the range 1 to 24 inclusive. This value also controls the depth of the pyramid.
- Cartesian tiles
- Number of digits in tile name
- Tile height (degrees)
- Tile height (metres)
- Tile span
- Tile width (degrees)
- Tile width (metres)
- Cartesian tiles: _bCartesian&
Are the tiles in a cartesian coordinate reference system?
- Number of digits in tile name: _nDigit&
The number of digits in the tile name.
- Projection: _projection$
The tile naming convention Coordinate Reference System.
- Scale: _scale#
The tile scale.
- Tile height (degrees): _degree_height#
The tile height, in degrees.
- Tile height (metres): _metre_height#
The tile height, in metres.
- Tile span: _span#
The tile span, in metres.
- Tile width (degrees): _degree_width#
The tile width, in degrees.
- Tile width (metres): _metre_width#
The tile width, in metres.