Table 1 Type identifier (TID) table with codes adhering to the standards of the General Bathymetric Chart of the Oceans (GEBCO), short data type name, description, weight (see also Table 2), and number of linked datasets featured in IBCSO v2.

10

Singlebeam

Depth value collected by a single beam echo-sounder

10

766

11

Multibeam

Depth value collected by a multibeam echo-sounder

5, 15, 20, 25, 30

464

12

Seismic

Depth value collected by seismic methods

10

21

13

Isolated sounding

Depth value that is not part of a regular survey or trackline

5

2

14

ENC sounding

Depth value extracted from an Electronic Navigation Chart (ENC)

5

3

17

Combination of direct measurements

Combination of direct measurement methods

5

2

40

Predicted bathymetry based on satellite-derived gravity data

Depth value is an interpolated value guided by satellite-derived gravity data

no weight

[1]

41

Interpolated based on a computer algorithm

Interpolated based on a computer algorithm - depth value is an interpolated value based on a computer algorithm (e.g. Generic Mapping Tools)

no weight

[1]

42

Digital bathymetric contours from charts

Depth value taken from a bathymetric contour dataset

5

1

45

Predicted bathymetry based on flight-derived gravity data

Depth value is an interpolated value guided by helicopter/flight-derived gravity data

10, 5

3

46

Draft of a grounded iceberg

Depth estimated by calculating the draft of a grounded iceberg using satellite-derived freebord measurement

10

1

70

Pre-generated grid

Depth value is taken from a pre-generated grid that is based on mixed source data types, e.g. single beam, multibeam, interpolation etc.

5

[2]

71

Unknown source

Depth value from an unknown source

5

1

72

Steering points

Steering points - depth value used to constrain the grid in areas of poor data coverage

no weight

[2]