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12 July12017 Landsat Science Team, Sioux Falls
Landsat, LGAC and Sentinel-2: disentangling coupled human-
environmental systems
Patrick Griffiths1, Dirk Pflugmacher1, Sebastian van der Linden1
Tobias Kuemmerle2,3
Patrick Hostert1,3
1 Geomatics Lab, Geography Department
2 Biogeography and Cons. Biology Lab, Geography Department
3 Integrative Research Institute on Transformations of
Human Environment Systems (IRI THESys)
Humboldt-Universität zu Berlin
2
Steffen et al. 2015, Science
Land systems analysis
From Land Cover to Land Use
3
Land systems analysis
From Land Cover to Land Use
Phenology related information is key for better understanding land use intensity (e.g. related to irrigation, double-cropping, mowing events…
Sparse cloud-free
Landsat observations in
NE-Germany in 2016
4
Sentinel2 & Landsat integration opportunities
No spatially explicit national scale information source on crop types available - LPIS treaded confidentially
Integration can provide observation frequency required to disentangle crop types and quantify growing season characteristics
5
National scale mapping
North South gradient in elevation and phenology
29 WRS2 frames, 62 MGRS tiles for national coverage
Time period covered: 275-2015 to 365-2016
HLS M30 & S30 products: bandpass adjusted, BRDF normalized, subpixel registered
6
Compositing
Compositing at narrow +/- weekly interval:
Temporal gap filling
Allows for standardized workflows and to prototype higher level product generation (Level-3 & beyond)
Parametric scoring approach provides quality assessment
DOY:
scene based
Cloud/Shadow distance:
pixel based
Sensor:
scene based
Clear sky fraction:
scene based
Si = (WDOY*SDOY)+(Wdist*Sdist)+(Wsen.*Ssen.)+(WHOT*SHOT)+(WskyF*SskyF)
∑(W)
Composite:
pixel based decision
Haze optimized transformation:
pixel based
Griffiths, P. & Hostert, P. Exploring the potential of the combined use of Sentinel2a and Landsat data for land cover and crop type mapping (in prep)
7
Clear observation count: HLS 275-2015 to 365-2016
1 55
Griffiths, P. & Hostert, P. Exploring the potential of the combined use of Sentinel2a and Landsat data for land cover and crop type mapping (in prep)
8
Observation composites
Gap-filled composites
275 2015 – 365 2016
9
Mapping
Detailed temporal & full spectral information required to disentangle e.g. cereal crops; temporal features suffice for other crops (e.g. maize); inclusion of red-edge bands improves results
Strategy: Per pixel 45 x 10-day composites with 9 spectral measurements provided to Random Forest classifier (30% of features considered at split; 500 trees; 3000 samples/class)
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Grassland mowing detection
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Overall accuracy 83.76%
PAC. UAC
Grassland 87.80 76.75
Winter Rye 81.10 71.96
Winter Wheat 68.40 73.79
Winter Barley 87.20 86.17
Maize 91.60 82.60
Winter Rapeseed 96.60 97.77
Summer Cereals 83.40 74.66
Fodder Crops 66.20 84.98
Sugar Beet 96.70 95.36
Sunflower 89.40 91.69
Potatoes 82.10 88.85
Mixed&Deciduous F. 68.57 78.78
Coniferous Forest 84.30 80.90
Built-up 77.40 80.54
Water 95.68 94.73
National scale mapping
12
13
14
15
16
17
18
DOY – First mowing detection
101 326
19
DOY - Second mowing detection
101 330
20
Large area LULC mapping: GeoMultiSens
Beta test: central Europe
• All Landsat TM, ETM+, OLI data
• 4,130 images for 2011-2013 31,243 training samples from EU LUCAS-2012 as
input for RF classification
Objective: Implement pan-European LULC and (forest disturbance) mapping from heterogeneous EO data sources
Europe 1985 – 2015, L 5/7/8 and S2
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EO data
User Data
Tiling
Scenes
Spatial
Reference
System
Tiling
Scheme
Data Cube Data Query
Temporal/Spatial
Extent
Metadata
Query
Surface Reflectance
Cloud Mask and QA
Metadata
Composite-based
feature extraction
Land cover map
Auxiliary
Geodata (z.B.
Bioclimatic
zones) Geodata / Zones
Composite
features
Extract training
samples
Classification
model
Machine learning
(Random Forest)
Model
application
Reference
samples
(LUCAS)
Training data
Vegetation indices,
transformations
Input data Analysis-ready data structure (Data cube creation) User query
Model training
Model application (Mapping)
Compositing (Feature extraction)
Automated workflow
Hostert, P., Pflug-
macher, D. et al.:
Sensor constellations
and big data from
space – from challen-
ges to solutions
(in prep.)
Scheffler, D., Hollstein, A., Diedrich, H., Segl, K., Hostert, P. (2017). AROSICS: An Automated and Robust Open-Source Image
Co-Registration Software for Multi-Sensor Satellite Data. Remote Sensing, 9, 676
22
GeoMultiSens Land Cover 2012
23
25 ha MMU
39 countries involved
3 years production time
Computer Assisted Photo-Interpretation
EU CORINE Land Cover 2012
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CORINE Land Cover
2012
25
GeoMultiSens Land Cover
2012
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Map accuracy (10 classes): 79.4%
Map accuracy (4 classes): 89.7%
Forest: 95.5% accuracy
Cropland: 88.7% accurate - confusion with shrub/grassland
High omission of bare land – but class is under-sampled and rare in Central Europe
Producer’s Accuracy User’s Accuracy
Map accuracy
27
Conclusions
Dense time series and phenology metrics from Landsat and Sentinel2 allow assessing land use, LU management and intensity
Data from sensor constellations is needed for analyzing LULC in data-sparse regions
Landsat science plays a vital
role in providing LULCC
evidence in support of the
UN SDGs
Acknowledgments:
• European Space Agency for Island2VAP
• German Federal Ministry of Education and
Research for GeoMultiSens
• Endorsed by the Global Land Programme
Thanks Landsat
Science Team!
Modified after Romijn et al. (2017): Monitoring progress towards Sustainable Development Goals The role of land monitoring