Reader Directives

The following table lists the keywords processed by the ASTER (HDF4) reader. The suffixes shown are prefixed by the current <ReaderKeyword> in a mapping file. By default, the <ReaderKeyword> for the ASTER (HDF4) reader is HDF4_ASTER.

DATASET

The value for this keyword is the name of the top-level file in the ASTER hierarchy. The typical extension for ASTER is .hdf.

Required/Optional

Required

Mapping File Syntax

HDF4_ASTER_DATASET “C:\DATA\HDF\GSUB1.A2001124.0855.003.200219309451.hdf.”

Workbench Parameter

Source Hierarchical Data Format 4 (HDF4) ASTER File(s)

FEATURE_TYPE_NAME

The values for this directive are listed in the table below. The Feature Type Name depends on the value used.

Value Feature Type Name Example

FORMAT_NAME

(default value)

<reader_type_name>

HDF4_ASTER

FILE_NAME <filename>

CURRENT_DHW

SUBDATASET_NAME <subdataset_name>

HDF4_EOS_EOS_SWATH_VNIR_Swath_ImageData1

FILE_NAME_AND_SUBDATASET_NAME <filename_subdataset_ name>

CURRENT_DHW_HDF4_EOS_EOS_SWATH_VNIR_Swath_ImageData1

Required/Optional

Required

Mapping File Syntax

FEATURE_TYPE_NAME FORMAT_NAME

Workbench Parameter

Feature Type Name(s)

APPLY_GCPS

Required/Optional: Required

The value for this keyword is either Yes or No. If set to Yes, then GCP information, including a GCP projection, will be read from the file and applied to the raster data as an affine transformation. If set to No, the GCP information is preserved as properties on the raster geometry. The default value for this directive is No.

Example:

APPLY_GCPS “YES”

Workbench Parameter: Apply GCPs

GCP_INTERPOLATION_METHOD

Required/Optional: Required

The value for this keyword is one of NearestNeighbor, Bilinear or Bicubic. If APPLY_GCPS is set to Yes, this directive must be specified. The default value for this directive is NearestNeighbor.

Example:

GCP_INTERPOLATION_METHOD “Bilinear”

Workbench Parameter: GCP Interpolation Method

SEARCH_ENVELOPE

Using the minimum and maximum x and y parameters, define a bounding box that will be used to filter the input features. Only features that interact with the bounding box are returned.

If all four coordinates of the search envelope are specified as 0, the search envelope will be disabled.

Mapping File Syntax

<ReaderKeyword>_SEARCH_ENVELOPE <minX> <minY> <maxX> <maxY>

Note: If all four coordinates of the search envelope are specified as zero, the search envelope will be disabled.

Required/Optional

Optional

Workbench Parameter

Minimum X, Minimum Y, Maximum X, Maximum Y

SEARCH_ENVELOPE_COORDINATE_SYSTEM

This directive specifies the coordinate system of the search envelope if it is different than the coordinate system of the data.

The COORDINATE_SYSTEM directive, which specifies the coordinate system associated with the data to be read, must always be set if the SEARCH_ENVELOPE_COORDINATE_SYSTEM directive is set.

If this directive is set, the minimum and maximum points of the search envelope are reprojected from the SEARCH_ENVELOPE_COORDINATE_SYSTEM to the reader COORDINATE_SYSTEM prior to applying the envelope.

Required/Optional

Optional

Mapping File Syntax

<ReaderKeyword>_SEARCH_ENVELOPE_COORDINATE_SYSTEM <coordinate system>

Workbench Parameter

Search Envelope Coordinate System

CLIP_TO_ENVELOPE

This directive specifies whether or not FME should clip features to the envelope specified in the SEARCH_ENVELOPE directive.

Values

YES | NO (default)

Mapping File Syntax

<ReaderKeyword>_CLIP_TO_ENVELOPE [yes | no]

Workbench Parameter

Clip To Envelope

EXPOSED_ATTRS

This directive allows the selection of format attributes to be explicitly added to the reader feature type.

This is similar to exposing format attributes on a reader feature type once it has been generated; however, it is even more powerful because it enables schema-driven applications other than Workbench to access and leverage these attributes as if they were explicitly on the schema as user attributes.

The result of picking a list of attributes is a comma-separated list of attribute names and types that will be added to the schema features. Currently all reader feature types will receive the same set of additional schema attributes for a given instance of the reader.

Required/Optional

Optional

Mapping File Syntax

Not applicable.

While it is possible for FME Objects applications to invoke this directive, the required format is not documented.

This directive is intended for use in our GUI applications (for example, Workbench) only.

Workbench Parameter

Additional Attributes to Expose