Download presentation
Presentation is loading. Please wait.
Published byLindsay Osborne Modified over 8 years ago
1
1 Work carried out by SCOT and KUL presented at VEGETATION 2000 Conference with the support of CNES and contribution of JRC and VTT
2
2 mAssessment of the capabilities of VEGETATION for mapping forest at regional scale mPreparation of a European forest map prototype mwith simple methods applied to standard VGT products (10 days composites S10) Partners JRC : methodology as developed for FMERS study KUL : alternative approach for stratification SCOT : processing VTT : clustering method
3
3 mData : 21 composites S10 from April 1999 to October 1999 mOther data : CORINE LC, JRC/FIRS stratification of European forest ecosystems mPan-European study area
4
4 mQuality of VEGETATION S10 data Decade #2 October 1999 Status map Clouds in dark blue Ice in light blue Bad SWIR sensors in red However problems of SWIR sensors cloud mask to be improved remaining directional effects High visual quality
5
5 S10 decade #2 October 1999 NIR/SWIR/R
6
6 S10 decade #2 October 1999 NIR/SWIR/R
7
7 m Mapping procedure Stratification utilisation of FIRS strata alternative using landscape criteria Spectral clustering Selection of the most appropriate S10 for forest types discrimination and generation of a multi-spectral monthly composite Stratified clustering of the monthly composite Multi-temporal analysis of NDVI forest types CORINE Land Cover
8
8 Two alternative location of cluster means in three ecosystem regions. A - means similarly distributed - no likely need for pre-clustering stratification. B - cluster means on the average different in different regions - a likely need for pre- clustering stratification.
9
9 FIRS stratification superimposed over VGT S10 # 2 October 1999
10
10 FIRS main regions after regrouping of main strata
11
11 m Stratification alternative using landscape criteria fragmentation patterns, e.g. Shannon index... proportion of main land cover categories Proportion of forest within 5x5 Km bloc from CORINE LC 0 % < 10 % 11-40 % 41-80 % > 81 %
12
12 m Generation of a monthly composite remaining clouds in all S10 products selection of three S10 composites D3 August 1999 D1 September 1999 D2 September 1999 averaging procedure with elimination of bad pixels in the SWIR band and remaining cloudy pixels expected to minimise directional effects
13
13 m Generation of a monthly composite 10 days composite #3 August 1999 monthly composite (#3 Aug / # 1 & 2 September 1999)
14
14 Monthly composite by averaging three decades D3/Aug, D1 and 2/Sept 1999
15
15 m Unsupervised clustering within each stratum into 50 classes algorithm developed by VTT (Finland) and tested in the framework of FMERS for European forest mapping with IRS-WiFS data based on homogeneous signatures within 2x2 pixels automatic sort of the clusters according to their approximate biomass values
16
16 Likely location of the target classes in the spectral range (FMERS/VTT)
17
17 m Unsupervised clustering within each stratum into 50 classes coniferous mixed Broad - leaved coniferous mixed Broad - leaved 15 20 confusion Discrimination with SWIR band
18
18
19
19 m contribution of the SWIR band
20
20 m NDVI temporal profiles definition of temporal indicators distinction of three “seasons” for better discrimination of NDVI profiles related to forest types April-MayJune-AugSept-Oct application to the 21 S10 composites
21
21 Colour composite NDVI three seasons
22
22 m Temporal profiles of main forest cover types
23
23 m Temporal profiles of other land cover types
24
24 m Temporal profiles of CORINE classes Quality of CORINE classes ? Variability of vegetation phenology within broad land cover classes
25
25 Prototype of a European Forest Map derived from VEGETATION data Coniferous forest Broad-leaved forest Mixed forest Evergreen vegetation
26
26 VEGETATION S10 products of very good quality : geometry, radiometry but some improvements are still needed : correction of directional effects, cloud masking… the spectral clustering approach is leading to promising results with simple methods and a few S10 products dramatic potential of NDVI temporal profiles for discriminating vegetation types : combination with spectral clustering ? need to improve and develop new standard products on NDVI profiles, e.g. phenology, … products on land cover changes
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.