Create a HyperGrid (HGD) from a Grid

The HGDIMG GX will create a hypergrid (HGD) file from a large grid or image file.

Create an HGD (HyperGrid) from a Grid

Grid/Image file

Select a grid or image file from which to create a HyperGrid.

Application Notes

A HyperGrid is an optimized read-only grid format for DAP servers and supports compression, extremely fast windowing, and multithreading. We recommend that very large grids or images that require frequent windowing to support client requests be provided to a DAP server in HyperGrid format.

The actual HyperGrid is made up of a set of compressed files as follows:

• .hgd:  the base grid index file.
• .hgd.gi: contains the georeferencing information.
• .hgd#: where ‘#’ is 0, 1, 2, 3, etc. These are individual compressed grids of the original data at resolutions that are factors of two differences in size.

All hgd files must be placed in a data directory in the DAP server data area for the DAP server to catalog the data.