Crop fields

Semi Evergreen forest

Deciduous forest

Leaf-off trees (Deciduous)

Fallow crop fields

Semi evergreen trees

cFRS DATA FOR FOREST TYPE DISCRIMINATION

Shimoga (Karnataka) has a good forest cover which comprises a mix of deciduous andsemi evergreen trees. Trees in a deciduous forest normally shed their leaves in thewinter season and again begin with a new set of leaves in spring.

Compact polarimetric data obtained from RISAT-1 FRS beam has the potential todistinguish between full leaf tree and a partial / no leaf tree. This is because the crown ofthe tree which consists of leaves and branches, exhibits different volumes at differenttimes causing the microwave scattering behaviour to be different.

FRS-1 RH,RV data acquired during the leaf-off season shows scattering from trunk andbare branches whereas the full leafy trees exhibit multiple / diffuse scattering .

This is evident from the image which was decomposed into three components of targetsshowing even bounce, diffuse and odd bounce which relate to double scattering (likefrom a pillar), multiple scattering (like multiple reflections from branches, leaves etc) andsurface scattering (like from a surface), respectively.

Even (Double) Bounce Diffuse (Volume/multiple) Odd bounce (surface)

Incident radiation

M-Delta Image: Fallow fields show surface (odd bounce) scattering ; deciduous forest patches show higher contribution of even bounce scattering due to less foliage during leaf-off period; Semi-evergreen forests show more diffuse

scattering due to higher foliage cover.

FCC of LISS-IV data of Jan. 08, 2016 m-delta decomposition composite of RISAT-1 cFRS-1 data of Jan. 01, 2016

(Even Diffuse Odd bounce scatterers)

Fallow Crop fields

Semi Evergreen forest

Deciduous forest

SHIMOGA (KARNATAKA) FOREST : A MULTI SENSOR PERSPECTIVE

The FRS-1 RH, RV data helps in the discrimination of deciduous patches from semievergreen patches of forest.

The LISS-IV FCC which shows low reflectance in the deciduous patches. This can bemisinterpreted as non-vegetated area. However, the same area is seen as orange tingedin FRS-1 processed data, highlighting the component of vertical structures.

The LISS-IV data and FRS-1 data was fused with the expectation of extracting maximuminformation. The intensity of SAR data combined with the Infra red, red and greenspectral bands of LISS-IV data highlights many significant features in the image.

FRS complex data Calibrated data in ground range m-delta decomposed data

Fallow Crop fields

Semi Evergreen forest

Deciduous forest

Fusion of data between LISS-IV and FRS-1.

The crop fields are current fallow.

The deciduous forest is clearly distinct from semi-evergreen forest patches. The dates of acquisition coincide with leaf fall season of the area.

Output image derived from Brovey fusion using Intensity from FRS-1; Infra-red, Red and Green from LISS-IV.