Spectral bands for Earth observation applications are selected on the basis of:
- spectral response-that is, the specific nature of signals reflected or emitted across a range of wavelengths-of features of interest, for example rocks and soils, vegetation, deserts, snow, moisture and urban areas
- atmospheric transparency and transmission stability, which can only be sufficiently ensured within certain spectral "windows"
SPOT 5 bands in the visible and short-wave infrared portions of the spectrum are identical to those on SPOT 4:
- panchromatic (wide band): 0.49 to 0.69 µm
- visible B0: 0.43 to 0.47 µm (on VEGETATION only)
- visible B1: 0.50 to 0.59 µm
- visible B2: 0.61 to 0.68 µm
- visible B3: 0.78 to 0.89 µm
- short-wave infrared (SWIR): 1.58 to 1.75 µm
The new HRS instrument acquires images in the panchromatic band only.
| Spectral band |
HRG
|
VEGETATION
|
HRS
|
| PA 0.49 -0.69 µm |
2.5 m* ou 5 m
|
-
|
10 m
|
| B0 0.43 - 0.47 µm |
-
|
1 km
|
-
|
| B1 0.49 - 0.61 µm |
10 m
|
-
|
-
|
| B2 0.61 - 0.68 µm |
10 m
|
1 km
|
-
|
| B3 0.78 - 0.89 µm |
10 m
|
1 km
|
-
|
| SWIR 1.58 - 1.75 µm |
20 m
|
1 km
|
-
|
| Swath |
60 km
|
2250 km
|
120 km
|
Spectral bands and resolution of SPOT 5 instruments
*Imagery at a resolution of 2.5 metres in the panchromatic band is obtained
using a sampling concept unique to SPOT 5, called Supermode. This concept
processes two 5-metre panchromatic images acquired simultaneously to generate
a single image at a resolution of 2.5 metres.
