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Landsat 7 ETM
This Landsat 7 ETM data was purchased by either NWT regional office of the Department of Indian Affairs and Northern Development, Canada, Industry Tourism and Investment, Government of the NWT, Environment and Natural Resources, Government of the NWT, or the Canada Centre for Topographic Information. Most of the data files are quite large and could take hours to download over a dial-up connection.
You need to determine the ID number of the image and image format of interest.
Then go to the Downloads and select the appropriate category. See the data history at the bottom of this page for notes on file updates.
Image ID numbers are of the form ixxx which represents the NWTCG index number.
Images that appear to be duplicates are the same image projected into two different UTM zones.
See the metadata inside the zip files for more details.
Tools to help you select the image ID of interest:
- Index map of the image areas jpg
pdf
(updated July 10, 2003).
- A list of image thumbnails image preview (updated Feb 8, 2005).
- Download a shp file from TM7shps.zip (5 MB) (updated July 17, 2003). The shp file shows the area coverage of each image. The zip file also includes the meta-data for most images.
- View or download these reference files of the image centroids TM7Centroids.xls TM7Centroids.htm Tm7Centroids_shp.zip (updated July 7, 2005)
Several image formats of the data are available. The GeoTIF files can be used in most GIS packages.
Some graphics programs and image viewers may be able to display them but they are very large files.
The ECW files can be viewed by most Geographic Information Systems and some other software but you need the appropriate (usually free) extension installed from www.ermapper.com. All files use the NAD 83 datum.
One of the formats available is "pan-sharpened". Pan-sharpening is a process of applying the high resolution panchromatic band to a 3 colour composite.
The resulting high resolution image has elements of the low resolution and high resolutions bands. Click here to see an example jpg pdf
The available versions are:
- Landsat 7 ETM mosaics, The mosaic is compiled from the pan-sharpened 543 band combination files.
Click here to see what they look like
jpg (134KB)
pdf (5.6MB)
ecwp
There are two versions available.
1) A low resolution (90 metre pixel size) image of the entire NWT. The projection is Lambert Conformal Conic, Central Meridian of 115.0 W, origin of 0.0 N, Standard parallels of 63.0 and 75.0. Available as an ECW (143 MB).
2) As UTM tiles of the pan-sharpened images in 543 band combination. The tiles are 6 degrees wide and 5 degrees tall with some overlap.
The index map has the tile boundaries and tile names.
To make downloading easier the tiles are split into top, mid and lower sections with no overlap. They are available in GeoTIFF (1.0 to 1.5 Gbytes each) and ECW formats (30-175 Mbytes).
- Landsat 7 ETM 543_PAN_TIF, 3 band geoTIF pan-sharpened in 543 band combination. These files are 12.5 metre resolution (300-500 Mbytes).
- Landsat 7 ETM 543_TIF , 3 band geoTIF in 543 band combination. Listed as ixxx_543_TIF.zip (100-175 Mbytes)
- Landsat 7 ETM 543_ECW, 3 band ECW in the 543 band combination. Listed as ixxx_543_ECW.zip (10-30 Mbytes)
- Landsat 7 ETM, The original ortho-corrected data as a 9 file geoTIF set as received from the supplier. To use these files you need an image analysis system. (150-400 Mbytes)
Plans
- Updating the mosaic with the new and updated files. The new mosaic will have more
of the gaps filled in, The mosaic will include more of Nunavut mainland and the western arctic islands,
the flaws in the image seams will be removed, the images will be better colour balanced,
the mosaics will have a better overlap profile making it easier to use related mosaic tiles. It will also
have 15 metre pixels instead of 12.5 metre pixels. Still to do on this update are the north end of zone 10 and zone 12 and east.
- Add the pan-sharpened TIF files for the new images.
- Update the related index files to reflect the new images.
Data History
- July 6, 2005, Added 12 pan-sharpened files for existing images.
- April 20, 2005, Updated the NT-NAD83_90_ecw, NT_09_65_1.TIF, NT_09_65.ECW and the NT_09.ecw.
- Feb 28, 2005, Replaced the NT_10_60 ecw and tif files with new versions.
- Feb 16, 2005, Replaced the NT_09_xx ecw and tif files with new versions.
- Feb 8, 2005, Added 57 new images and replacement TM7, TIF and pan-sharpened and ECW files.
- May 27, 2004, Replaced the NT_08_xx and NT_11_xx ecw and tif files with new versions.
- May 27, 2004, Deleted all the old TIF files as these were not usable.
- March 2, 2004, Added 45 new images and replacement TM7, TIF and ECW files.
- July 18, 2003, Updated the ecw and tif files for tiles 08-65, 09-65, 10-65, 13-60 and NT-NAD83_125.
- July 10, 2003, Added 25 TM7 images, TIF, ECW, Pan-sharpened TIFs.
- June 19, 2003, Make 148 Pan-sharpened TIF images available.
- May 14, 2003, Release the Pan-sharpened mosaic files.
- May 9, 2003, Create ECW versions of the UTM zone tiles.
- April 30, 2003, Deleted the 742 band combination files.
- April 15, 2003, Make 148 Pan-sharpened ECW images available.
- April 14, 2003, Updated the TM7.jpg and TM7.pdf with new images.
- April 3, 2003, added the new individual shp files to the TM7shps.zip.
- April 2, 2003, Added new images and updated the preview page.
- Feb 14, 2003, Added 75 images to the TM7_ETM category.
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