Page Comparison

Measurement type:

Depth

File format:

GeoTIFF

File:

Data type:

32bit floating point

Data/Pixel units

metres

Band number:

1

Description:

Distance from the seabed to sea surface in metres. Depth is a negative value which displays elevation as a positive value.

No data value:

NaN

Valid data range:

[0 to –12,000]

Tiled with X and Y block sizes:

[512, 512]

Compression:

Deflate, Level-6 predictor-3

Pyramids:

Yes   . Levels will be [8, 16, 32]. Compress the pyramids using deflate.  Bi-linear resampling

Output Coordinate Reference System (CRS):

EPSG 4326 (geographic decimal degrees); except where source is UTM using WGS84

Horizontal Datum:

WGS84

H_Output Units:

Variable (Geographic - decimal degrees, UTM – metres)

Vertical Datum:

EGM2008 height (EPSG:3855)

V_Output Units:

metres

Output name:

filename || _OV.TIFF

Measurement type:

Density

File format:

GeoTIFF

File:

Data type:

16bit Unsigned Integer (UInt16)

Data/Pixel Units

Count (Frequency counts of points per pixel)

Band number:

1

Description:

Number of soundings per cell/node. A node forms a cell in a bathymetry grid with a value displaying density, which is derived from the number of soundings within that node. Sounding density can inform optimal bathymetry data resolution.

No data value:

0

Valid data range:

[0, 65535]

Tiled with X and Y block sizes:

[512, 512]

Compression:

Deflate, Level-6 predictor-2

Pyramids:

None

Output Coordinate Reference System (CRS):

Output Coordinate Reference System (CRS): EPSG 4326 (geographic decimal degrees); except where source is UTM with WGS84 as the datum

Horizontal Datum:

WGS84

H_Output Units:

Variable (Geographic - decimal degrees, UTM – metres)

Vertical Datum:

EGM2008 height (EPSG:3855)

V_Output Units:

metres

Output name:

filename || .TIFF

Measurement type:

Uncertainty

File format:

GeoTIFF (32bit floating point)

File:

Data type:

Float32

Data/Pixel Units

Uncertainty (preferred) and/or Standard Deviation (only if CUBE is used) decimals

Band number:

1

Description:

A measure of a soundings confidence that is a proxy for horizontal and vertical accuracy. A higher density of soundings contributes to lowering uncertainty. Calculated from the distance a sounding is from a cell/node. When filtering, an uncertainty of 2 contains 95% of points closest to a cell/node.

No data value:

NaN

Valid data range:

–  [0, 1], inf

Tiled with X and Y block sizes:

[512, 512]

Compression:

Deflate, Level-6 predictor-3

Pyramids:

None

Output Coordinate Reference System (CRS):

EPSG 4326 (geographic decimal degrees); except where source is UTM with WGS84 as the datum

Horizontal Datum:

WGS84

H_Output Units:

Variable (Geographic - decimal degrees, UTM – metres)

Vertical Datum:

EGM2008 height (EPSG:3855)

V_Output Units:

metres

Output name:

filename || .TIFF

Measurement type:

Hillshade

File format:

GeoTIFF

File:

Data type:

UINT8

Data/Pixel Units

unitless

Band number:

1

Description:

Hillshade

No data value:

0

Valid data range:

1-255

Tiled with X and Y block sizes:

[512, 512]

Compression:

Deflate, Level-6 predictor-3

Pyramids:

Yes   Levels will be [8, 16, 32]. Compress the pyramids using deflate.  Bi-linear resampling

Output Coordinate Reference System (CRS):

Output Coordinate Reference System (CRS): EPSG 4326 (geographic decimal degrees); except where source is UTM with WGS84 as the datum

Horizontal Datum:

WGS84

H_Output Units:

Variable (Geographic - decimal degrees, UTM – metres)

Vertical Datum:

EGM2008 height (EPSG:3855)

V_Output Units:

metres

Output name:

filename || .TIFF