|
 |
Irs
Products
|
Processing Level
IRS data are typically available processed as System Corrected. This means that the products are radiometrically and geometrically corrected to the user-specified parameters including output map projection, image orientation, and resampling kernel (see after).
Geometric Corrections include Earth rotation, Earth ellipsoid and map projection, satellite attitude and internal sensor distorsion
From Euromap products are also available corrected only Radiometrically (not geometrically) for PAN and LISS-III.
System Corrected images can be produced with 2 different orientations: path oriented, displaying on the same rows the satellite acquisition scan lines, or map oriented, with north-up display.
From Euromap it is possible to have for LISS-III a synthetic blue band. Euromap has developed a model to derive a synthetic blue band on the basis of the 3 recorded LISS bands covering the green, red and near IR portion of the spectrum and a library of signatures. The resulting natural color renditions have proven to be of excellent quality and are particularly useful for the production of IRS PAN/LISS merged scenes. The blue band can be ordered as an option.
No atmospheric corrections are applied to the images.
Resampling algorithm
Level 1G images, during the geometric correction, are resampled to a regular output grid. The resampling kernel specifies how the input pixels are sampled: how many and how they are weighted. The available algorithms are:
Nearest Neighbour: in the transformed geometry the radiometric value of the output pixel is set equal to the value of the nearest input pixel in the original geometry. This algorithm preserves at its maximum the original radiance values.
Cubic Convolution: in the transformed geometry
the radiometric value of the output pixel
is interpolated using the values of its
16 nearest neighbours in the original geometry.
This algorithm produces a better looking
image, but changes the original satellite
radiometry.
IRS products and
formats by Ground Station
|
| |
Map Projections and Ellipsoids
UTM/WGS84 are available from all ground stations. |
| |
|
|
|
|
