Home -> Features: database and queries

HIS database and queries: Main


The database consists of two main parts:

  • seamless database of depths (soundings) and
  • database of objects.
    The objects for the system are collected and updated from hydrographic surveys -
    survey areas, wrecks, rocks and obstructions.
    For every object extensive information can be stored in HIS,
    containing its location, classification and attributes, and also images.
    The navaids and harbours data are taken from other databases

Queries can be

  • Textual, made, using query builders for any data type in HIS;
  • Spatial, made by keying in coordinates or drawing polygons on a map.
    Defined areas act as additional restriction to textual query if so desired;
  • combined.
Outputs can be redirected to tables on screen or to different types of files.

The HIS stores and displays the following data:

  • Survey areas - borders and meta-data:
    meta-data includes area status, area size, total survey line lengths, amount of survey lines, survey time, equipment, ship, surveyor, data cleaner, data validator, statistical data (min/max depths and coordinates, amount of points), quality estimators (standard deviation, mean, IHO S-44 order evaluations). Quality estimation is based on overlapping depths from different survey lines.
  • Depths in up to 1m resolution:
    Cells store depths in 11 different resolutions from 4m to 200m.
    On a web map, depths are shown from cells, so starting from 4m resolution.
    Cells also store depth contours at 1m intervals.
  • Underwater objects: rocks, wrecks and obstructions.
    Wrecks can have a number of different information ranging from simple dimensions and coordinates through to lengthy records comprising ship's history and different pictures of the wreck and the ship.

The HIS is also linked to some other databases.
Particular version shows information about aids to navigation and harbours. This is useful for getting a complete overview of data in some regions.

The HIS also shows WMS data in the background -
currently Estonian land maps, orthophotos and S-57 cells from PRIMAR.