FITS (Flexible Image Transport System) Reader/Writer

FME Format Type Identifier

FITS

Reader/Writer

Both

Typical File Extensions

.fits, .fit, .fts

The FITS Reader/Writer allows FME to read and write data in the Flexible Image Transport System format version 4.0, an open standard used primarily in astronomy.

FITS Product and System Requirements

Format

FME Platform

Operating System

Reader/Writer

FME Form

FME Flow

FME Flow Hosted

Windows 64-bit

Linux

Mac

Reader

Yes

Yes

Yes

Yes

Yes

Yes

Writer

Yes

Yes

Yes

Yes

Yes

Yes

FITS can contain any number of multispectral raster images, non-spatial ASCII tables, and non-spatial binary tables. Each of these is its own HDU (Header and Data Unit), so each can have its own set of metadata attributes.

FITS images can be georeferenced, but we currently only support georeferencing for images which use latitude and longitude and have this planetary extension, and not celestial referencing. Even so, this often will result in custom coordinate systems in FME, constructed from the coordinate system parameters, rather than existing named coordinate systems. Regardless of mapping to a custom FME coordinate system or not, the original celestial or WCS source reference system information is preserved by the reader in the form of format attributes.

The FITS writer supports update and delete operations on rows in the ASCII or binary tables using the implied row number specified by an input attribute. By default, the FITS reader will produce a fits_id attribute that indicates the internal file row number from which a feature was read.

Note  The FITS writer will write all header data as long strings and not maintain numeric data types – this may cause problems for other FITS readers.

Terminology Notes

Definition or FME Representation

FITS Equivalent Definition

dataset

FITS file

feature
  • data table row
  • single raster image (possibly with several bands)

feature type
  • data table (ASCII or binary)
  • either all the rasters or one raster, depending on the choice of the Feature Type Name option

Reader Overview

FME considers a single FITS file to be a dataset.

Writer Overview

The writer will store images into individual HDUs, and each non-spatial feature type will be represented by a table, all in one FITS file.

The writer has the following capabilities:

  • Raster Creation
  • Table Creation
  • Table Update

FME Raster Features

FME raster features represent raster data and use several concepts that are unlike those used in the handling of vector data.

For comprehensive information about how FME processes raster data, see Rasters.

FITS supports rasters with any number of bands.