ACRES GeoTIFF Format specifications

The table below provides details of ACRES GeoTIFF-format Landsat products.

GeoTIFF product specifications

Sensor	Landsat 7 ETM+ and Landsat 5 TM
Spectral bands	All bands of Landsat, one band as one GeoTIFF file
Data type	8 bit unsigned integer supplied as single bands
Processing level	Ortho-corrected and Map oriented image
Projections	UTM and EQUIRECTANGULAR (Geographic)
Datums	AGD66, GDA94 and WGS84
Scene size	Up to Triple scene
Delivery method	CD-ROM, DVD-R and FTP
Price	Same as other Landsat formats
Radiometric characteristics	Original data is maintained and customers should apply their own image stretching

PLEASE NOTE: There is no definitive GeoTIFF format. Not all image processing software will support the geocoding information contained in ACRES GeoTIFF products. The table below identifies the support, by commonly used image processing software, of the geocoding information contained in ACRES GeoTIFF-format products.

Support for geocoding metadata of ACRES GEOTIFF-format Landsat products

Projection	UTM	UTM	UTM	EQUIRECTANGULAR	EQUIRECTANGULAR	EQUIRECTANGULAR
Datum	AGD66	GDA94	WGS84	AGD66	GDA94	WGS84
Imagine 8.6	Y	N	Y	Y	N	Y
ERMapper 6.4	Y	Y	Y	Y	Y	Y
ER Viewer 2.0e	Y	Y	Y	Y	Y	Y
MapInfo	Y	Y	Y	Y	Y	Y
ArcGIS 8.3	Y	N	Y	Y	N	Y
ENVI 4.0	Y	N	Y	Y	Y	Y

To verify GeoTIFF geocoding support by your software, sample GeoTIFF products can be downloaded from the ACRES ftp site. Please check that cursor location and projection information is displayed correctly for the sample GeoTIFF in your processing package. ACRES strongly encourages users to test this prior to placing image orders.

• Details on Map Projection options for ACRES Optical Image products.

File Structure

ACRES GeoTIFF products contain two files, "label.txt" and Qarptchk_opt.txt, and one main directory "scene01".

The "label.txt" contains a brief summary of metadata information.

The "Qarptchk_opt.txt" contains quality assurance information.

The "scene01" directory lists all individual bands of Landsat data (tfw files and tif files), a report.txt, and a jpg file. The report.txt contains detailed metadata information about the product. The jpg file shows a quick thumbnail image for viewing purposes. Also, for the jpg file there is a jgw file containing the coordinate information.

The tfw files only contain the transformation information and tif files contain the image data for each band. A tfw file is a short six line ASCII file. Each ASCII tfw file has six values per line:

pixel x size
rotation about the y axis
rotation about the x axis
- pixel y size
x of upper left pixel
y of upper left pixel

For example:

25 (pixel x size)
0 (rotation about the y axis)
0 (rotation about the x axis)
-25 (- pixel y size)
656414 (x of upper left pixel)
8464763 (y of upper left pixel)

• To keep up to date with the progress and changes to GeoTIFF specifications visit: www.RemoteSensing.org

 

• Back to [ACRES File formats]