| Whiteshell Provincial Park, Manitoba, near Ontario |
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Natural Resources Canada > Earth Sciences Sector > Priorities > Canada Centre for Remote Sensing
Tour Canada from space Whiteshell Provincial Park, Manitoba, near Ontario
 Here at the Manitoba/Ontario border, we see another more natural boundary, the Canadian Shield. The Shield is quite exposed at the top right part of the image but becomes more hidden with substantial soil overburden on the left and bottom portions of the image. Significantly different land cover features result, and we see these through the remarkable textures, shapes and colours displayed. The exposed Shield is home to a very different type of upland vegetation than the soil-rich areas, which foster large wetlands. The shapes of the lakes also tell the story of the past presence and movement of glaciers. Human impact on the landscape is not as dramatic here, but is still quite visible and telling.
Question: If the vegetation is green, much as we would see it from space, then why do the bare rocks and some wetland vegetation appear in unnatural colours on this image, contrary to how the human eye would see it? [ Answer ]
About this Image
| Location: |
Whiteshell Provincial Park, Manitoba, near Ontario |
| NTS map(s): |
52 E |
 Location Map: |
See a detailed map (1:1M) of the region |
| Image Date: |
October 3, 1995 |
| Satellites/Sensors: |
Landsat TM bands 3, 4, 5 = B, G, R |
| Resolution: |
50 m, image segments: 30 m pixels |
| Image Area: |
33 x 40 km |
| Image Features: |
Wetlands, moisture conditions, height of land, rush, sedge, marsh, bog, fen, macrophytes, highway, service road, golf course, fairways, rock outcrop, kettle lake, soil overburden, hydro line, deciduous, coniferous, road, sediment, lake |
| Related Tour Images: |
Liard River Valley, Yukon; Trepassey, Newfoundland |
| Related Glossary Terms: |
These terms from the CCRS Glossary may help you to understand this image and its interpretation:
additive colour, false colour composite, true colour, plant reflectance, tone |
| Related Tutorial Sections: |
These sections of the "Fundamentals of Remote Sensing" tutorial by CCRS will help you to better understand this image and its interpretation:
2.8 4.2 5.5 5.7.2 |
| Image Credits: |
Received and analyzed by the Canada Centre for Remote Sensing
Preprocessed by RADARSAT International Inc. |
|
Additional
Information: |
The National Wetlands Working Group has produced a Canadian wetland classification system which divides wetlands into five broad classes: bog, fen, swamp, marsh and shallow open water, and these classes are further subdivided into wetland forms. There is also a classification of wetland type based on the general physiology of the vegetation cover. |
| Question: |
If the vegetation is green, much as we would see it from space, then why do the bare rocks and some wetland vegetation appear in unnatural colours on this image, contrary to how the human eye would see it? |
| Answer: |
While most of the vegetation appears a natural green colour, the image is actually a "false colour" composite made from a combination of Landsat TM bands 5, 4 and 3 displayed in red, green and blue light respectively. The original spectral sensitivities of these three bands are:
- 1.55-1.75 micrometres (near infrared)
- 0.76-0.90 micrometres (near infrared)
- 0.63-0.69 micrometres (red)
It is because they are displayed with light that is a different colour than their original spectral sensitivities that the composite is called "false colour". But then it wouldn't do much good to display an infrared-sensitive band in infrared light, since our eyes cannot detect that spectral band. Therefore the "unnatural" colour appearance of rocks and wetland areas in the image is because the image is made up of some spectral bands that we cannot naturally see.
|
TM
Band |
Spectral
Sensitivity
(micrometres) |
Spectral
Sensitivity
(common name) |
Display
Colour |
| 3 |
0.63-0.69 |
red |
blue |
| 4 |
0.76-0.90 |
near infrared |
green |
| 5 |
1.55-1.75 |
near infrared |
red |
|
