S102 -- S-102 Bathymetric Surface Product

Driver short name

S102

Build dependencies

libhdf5

Added in version 3.8.

This driver provides support for bathymetry data in the S-102 format, which is a specific product profile in an HDF5 file.

S-102 files have two image bands representing depth (band 1), uncertainty (band 2) values for each cell in a raster grid area.

Note that positive values of depth mean values below the reference surface of the vertical datum. The DEPTH_OR_ELEVATION open option can be set to ELEVATION to expose depth values as elevation values, by negating their sign (i.e. positive values of elevation mean values above the reference surface)

Georeferencing is reported.

Nodata, minimum and maximum values for each band are also reported.

For reading, supported versions of the specification are S-102 v2.1, v2.2 and v3.0.

Since GDAL 3.12, multiple feature instance groups per dataset (to encode grids using different vertical datums) are supported. In that case, each feature instance group is exposed as a GDAL subdataset, whose name is of the form S102:"{filename.h5}":BathymetricCoverage.{XX}.

Write support for S-102 v3.0 has been added in GDAL 3.13

Driver capabilities

Supports CreateCopy()

This driver supports the GDALDriver::CreateCopy() operation

Supports Georeferencing

This driver supports georeferencing

Supports VirtualIO

This driver supports virtual I/O operations (/vsimem/, etc.)

Open options

Open options can be specified in command-line tools using the syntax -oo <NAME>=<VALUE> or by providing the appropriate arguments to GDALOpenEx() (C) or gdal.OpenEx (Python). The following open options are supported:

  • DEPTH_OR_ELEVATION=[DEPTH​/​ELEVATION]: Defaults to DEPTH. Whether to report depth or elevation. Positive values of depth mean values below the reference surface of the vertical datum. Positive values of elevation mean values above the reference surface of the vertical datum (which is the convention used by the BAG driver)

  • NORTH_UP=[YES​/​NO]: Defaults to YES. Whether the top line of the dataset should be the northern-most one.

    This is the default behavior of most GDAL formats, but the native organization of the data in S-102 products is to have the first line of the grid being the southern-most one. This native organization can be exposed by the driver by setting this option to NO (in which case the 6th term of the geotransform matrix will be positive)

Spatial metadata support

Starting with GDAL 3.9, GDAL can handle QualityOfSurvey (or QualityOfBathymetryCoverage in S102 v3.0) spatial metadata.

When such spatial metadata is present, the subdataset list will include a name of the form S102:"{filename}":QualityOfSurvey ( or S102:"{filename}":QualityOfBathymetryCoverage in S102 v3.0)

The /QualityOfSurvey/featureAttributeTable (/QualityOfBathymetryCoverage/featureAttributeTable in S102 v3.0) dataset is exposed as a GDAL Raster Attribute Table associated to the GDAL raster band. The pixel values of the raster match the id column of the Raster Attribute Table.

Write support

Added in version 3.13.

Creation of a S-102 v3.0 dataset from another existing GDAL supported dataset is possible using the GDALDriver::CreateCopy() function, or utilities like gdal_translate or gdal raster convert. The input dataset must have one or two bands. The first band must represent depths (positive values are down below the vertical datum surface) in meters, and the optional second band must contain the uncertainty value in meters. If the first band has a description "elevation" (typically for BAG datasets), elevations will be automatically converted to depths by negating the sign of source values.

The input dataset must be in the following CRS:

  • WGS 84 longitude/latitude (EPSG:4326)

  • Any of the 60 north/south UTM projected CRS over WGS 84 (EPSG:32601 to 32660, or 32701 to 32760)

  • "WGS 84 / UPS North (E,N)" (EPSG:5041)

  • "WGS 84 / UPS South (E,N)" (EPSG:5042)

If several vertical datums are needed, the APPEND_SUBDATASET creation option can be set to YES to add an extra feature instance group ("BathymetricCoverage.XX") to an existing S-102 dataset.

The following creation options are available:

  • VERTICAL_DATUM=<string>: Vertical datum. This is a required creation option.

    Possible values are either a S100 vertical datum numeric code in the 1 to 30 range, or value 44. Or their string meaning or abbreviation among the following list:

    • 1: meanLowWaterSprings / MLWS

    • 2: meanLowerLowWaterSprings

    • 3: meanSeaLevel / MSL

    • 4: lowestLowWater

    • 5: meanLowWater / MLW

    • 6: lowestLowWaterSprings

    • 7: approximateMeanLowWaterSprings

    • 8: indianSpringLowWater

    • 9: lowWaterSprings

    • 10: approximateLowestAstronomicalTide

    • 11: nearlyLowestLowWater

    • 12: meanLowerLowWater / MLLW

    • 13: lowWater / LW

    • 14: approximateMeanLowWater

    • 15: approximateMeanLowerLowWater

    • 16: meanHighWater / MHW

    • 17: meanHighWaterSprings / MHWS

    • 18: highWater / HW

    • 19: approximateMeanSeaLevel

    • 20: highWaterSprings

    • 21: meanHigherHighWater / MHHW

    • 22: equinoctialSpringLowWater

    • 23: lowestAstronomicalTide / LAT

    • 24: localDatum

    • 25: internationalGreatLakesDatum1985

    • 26: meanWaterLevel

    • 27: lowerLowWaterLargeTide

    • 28: higherHighWaterLargeTide

    • 29: nearlyHighestHighWater

    • 30: highestAstronomicalTide / HAT

    • 44: balticSeaChartDatum2000

  • ISSUE_DATE=<string> as <YYYYMMDD>: If not specified, defaults to the current date.

  • ISSUE_TIME=<string>: Issue time as <hhmmssZ> or <hhmmss[+-]HHMM>

  • HORIZONTAL_POSITION_UNCERTAINTY=<number>: Horizontal position uncertainty in meter

  • VERTICAL_UNCERTAINTY=<number>: Vertical uncertainty in meter

  • QUALITY_DATASET=<string>: Path to a dataset with the quality of bathymetric coverage (spatial metadata).

    This must point to a GDAL recognized dataset, with a single band of an integer data type, containing quality codes. The band must be associated with a raster attribute table, with an integer column named id for each value in the band pixels, and optional columns among the ones allowed by the S-102 specification:

    • dataAssessment (uint8)

    • featuresDetected.leastDepthOfDetectedFeaturesMeasured (boolean)

    • featuresDetected.significantFeaturesDetected (boolean)

    • featuresDetected.sizeOfFeaturesDetected (float32)

    • featureSizeVar (float32)

    • fullSeafloorCoverageAchieved (boolean)

    • bathyCoverage (boolean)

    • zoneOfConfidence.horizontalPositionUncertainty.uncertaintyFixed (float32)

    • zoneOfConfidence.horizontalPositionUncertainty.uncertaintyVariableFactor (float32)

    • surveyDateRange.dateStart (date)

    • surveyDateRange.dateEnd (date)

    • sourceSurveyID (string)

    • surveyAuthority (string)

    • typeOfBathymetricEstimationUncertainty (enumeration)

  • COMPRESS=[NONE​/​DEFLATE]: Defaults to DEFLATE. Compression for elevation and uncertainty grids.

  • ZLEVEL=1-9: Defaults to 6. Deflate compression level.

  • BLOCK_SIZE=<integer>: Chunking size of the HDF5 arrays. Default to 100, or the maximum dimension of the raster if smaller than 100.

  • APPEND_SUBDATASET=[YES​/​NO]: Defaults to NO. Whether to append the new dataset to an existing S-102 dataset as an extra feature instance group ("BathymetricCoverage.XX")

Validation script

Added in version 3.13.

The Python script validate_s102.py can be used to validate the conformity of a S-102 v3.0 dataset against the specification. It requires the h5py Python module to be installed (typically through "pip install h5py")

Its usage is:

$ python validate_s102.py 102TESTXXXX.h5

Note that the GDAL S-102 reader is more tolerant that the validation script and can read files with slight non-conformities.

Examples

  • Converting a GeoTIFF with depth and uncertainty and another one with quality information to a S-102 dataset

    $ gdal_translate depth_uncertainty.tif 102TESTXXXX.h5 -of S102 -co VERTICAL_DATUM=MMLW -co QUALITY_DATASET=quality.tif

See Also