Downtime expected shortly as all LEDAS services are moved to a new server.
HDS is a file-based hierarchical data system designed for the storage of
a wide variety of information. It is particularly suited to the storage
of large multi-dimensional arrays (with their ancillary data) where
efficient access is needed.
HDS organises data into hierarchies, broadly similar to the directory
structure of a hierarchical filing system, but contained within a
single HDS container file. The structures stored in these files are
self-describing and flexible; HDS supports modification and extension of
structures previously created, as well as deletion, copying, renaming,
All information stored in HDS files is portable between the machines on
which HDS is implemented. Thus, there are no format conversion problems
when moving between machines.
Further information on HDS files can be obtained from Starlink.