Spatial Coverage

Definition

Syntax

Group: Spatial_Coverage
   Southernmost_Latitude:
   Northernmost_Latitude:
   Westernmost_Longitude:
   Easternmost_Longitude:
   Minimum_Altitude:
   Maximum_Altitude:
   Minimum_Depth:
   Maximum_Depth:
End_Group

Specifications

• The group may be used as often as necessary.
• Each field in the group may appear only once.
• Longitude must be specified in whole degrees, 0-180 east or west of the Prime Meridian (Greenwich). To indicate direction from the Prime Meridian, either the letters E or W should come right after the number with no space in between, or the symbols + or - should come right before the number with no space in between.
• Latitude must be specified in whole degrees, 0-90 north or south of the Equator. To indicate direction from the Equator, either the letters N or S should come right after the number with no space in between, or the symbols + or - should come right before the number with no space in between.
• Either +/- or N,S,E,W must always be specified. It is not permitted to assume that absence of direction implies + (i.e., N for latitude or E for longitude).
• If latitude or longitude are specified, all four values must be specified.
• Up to 80 characters are permitted for the altitude and depth fields. Characters may be selected from the printable ASCII character set.

More Definitions

• Minimum Altitude: the altitude level which represents the lower limit of data coverage, as measured from mean sea level.
• Maximum Altitude: the altitude level which represents the higher limit of data coverage, as measured from mean sea level.
• Minimum Depth: the depth level which represents the upper-most depth of data coverage, as measured from mean sea level.
• Maximum Depth: the depth level which represents the lowest depth of data coverage, as measured from mean sea level.

Recommendations

• Pay careful attention to coordinates when specifying the bounding box of the data set. Remember that the Southernmost_Latitude may be in the Northern Hemisphere. Likewise for the other coordinates: Northernmost_Latitude may be in the Southern Hemisphere, Westernmost_Longitude may be in the Eastern Hemisphere, and Easternmost_Longitude may be in the Western Hemisphere.
• If data coverage extends over the North Pole, the Northernmost_Latitude is 90N (or +90), the Southernmost_Latitude is the southernmost extent of the data, the Easternmost_Longitude is 180E (or +180), and the Westernmost_Longitude is 180W (or -180).
• If data coverage extends over the South Pole, the Southernmost_Latitude is 90S (or -90), the Northernmost_Latitude is the northernmost extent of the data, the Easternmost_Longitude is 180E (or +180), and the Westernmost_Longitude is 180W (or -180).
• If data coverage extends over the International Date Line (180deg Longitude), the Easternmost_Longitude of the data will likely be in the Western Hemisphere, and the Westernmost_Longitude will likely be in the Eastern Hemisphere.
• Some examples of altitude and depth units are 'm' (meters), 'km' (kilometers), 'ft' (feet), 'surface', 'hPA' (hecto Pascals), and 'mb' (millibars).

Examples

Group: Spatial_Coverage
   Southernmost_Latitude: 20N
   Northernmost_Latitude: 40N
   Westernmost_Longitude: 60E
   Easternmost_Longitude: 120E
   Minimum_Altitude: 1000 mb
   Maximum_Altitude: 50 mb
End_Group

Group: Spatial_Coverage
   Southernmost_Latitude: -90
   Northernmost_Latitude: -63
   Westernmost_Longitude: -180
   Easternmost_Longitude: +180
End_Group

Group: Spatial_Coverage
   Southernmost_Latitude: 40S
   Northernmost_Latitude: 50N
   Westernmost_Longitude: 160E
   Easternmost_Longitude: 130W
   Minimum_Depth: surface
   Maximum_Depth: 1500 m
End_Group

Group: Spatial_Coverage
   Southernmost_Latitude: -90
   Northernmost_Latitude: +90
   Westernmost_Longitude: -180
   Easternmost_Longitude: +180
End_Group