igarss_2011_breunig_DLR_TDM_water_mask.ppt

Water Body Detection from TanDEM-X Data: concept & first evaluation of an accurate water indication mask A. Wendleder 1) , M. Breunig 1) , K. Martin 2) , B. Wessel 1) , A. Roth 1) 1) German Aerospace Center DLR | 2) Company for Remote Sensing and Environmental Research SLU IGARSS 2011 / Vancouver / 2011-07-28 IGARSS’11, Vancouver

Outline
Introduction
Definition of the TanDEM-X water indication mask
Challenges for TanDEM-X water body detection
Concept & methodology of water body detection
Test site demonstration
Evaluation of classification results
Outlook
Slide

Definition of the TanDEM-X water indication mask
Global mission – global DEM – global water body mask
Water body mask primarily extracted for post-processing DEM editing
ongoing work in flattening of outpoking water bodies
correct orthorectification of remote sensing data
No production of a complete global water body inventory
Slide Kurnool Kadapa Channel / India frozen Lake Taimyr / Russia

Challenges for TanDEM-X water body detection
TanDEM-X mission with 2 global acquisition data sets in 2011 & 2012
The water body detection runs completely data-driven
Processing at Raw DEM level (30*50 km ≈ 8.000*10.000 pixels)
400 up to 800 Raw DEM per day to be processed
Therefore maximum computing time of 3 minutes per product
Applicable for different appearances of water bodies worldwide (coastline, inland lake, river, tropical, arctic, arid or humide climates etc.)
Slide tropical river & coastline in Indonesia small inland water bodies in Minnesota / USA

Concept & Methodology (I)
Input images are amplitude & coherence image
Exclusion of desert & polar regions
SRTM WAM
MODIS/Terra Land Cover Types
Exclusion of steep terrain
SRTM DEM
Slide

Concept & Methodology (II) Slide
Median filter separately applied both to amplitude & coherence image
Threshold method with fix threshold values
Two different thresholds to handle complexity of water appearance
1. threshold: reliable classification
2. threshold: potential classification
Calculation of water body areas via Chain Code and elimination of water bodies < 1 hectare
Fusion of three intermediate water body layers

Test site demonstration
River Elbe, Hamburg, Germany
acquired on January 27, 2011
Incidence angle 43.4° to 45.7°
Slide

Evaluation of classification results (I) Slide
Calculation of completeness and correctness
reference vector layer data of digital landscape models from the Authoritative Topographic Cartographic Information System (ATKIS)

Evaluation of classification results (II) Slide ATKIS: Authoritative Topographic Cartographic Information System Reference Completeness Correctness Amplitude ATKIS 86.9 % 92.6 % ATKIS water bodies > 1hectare 88.1 % 92.5 % Coherence ATKIS 79.8 % 98.7 % ATKIS water bodies > 1hectare 80.9 % 98.7 %

Evaluation of classification results (III)
Water body mask derived of amplitude image
rich in detail
susceptible to misclassifications
Water body mask derived of coherence image
significant and robust results
loss of details of small scale water bodies
Maximum of a correct & complete water mask with combination of both
Slide

Outlook
Accuracy assessment of the water body detection for different climate zones
robustness & global transferability of our approach
Mosaicking of different water bodies (neighboring acquisitions resp. first & second year acquisition) to an intermediate & final TanDEM-X water body mask product
TanDEM-X DEM editing using TanDEM-X water body mask
flattening of outpoking water bodies
Slide

Slide River Elbe, Hamburg, Germany
SAR image
Water indication mask
DEM
edited DEM

Slide Thank you for your attention! Anna Wendleder | Markus Breunig German Remote Sensing Data Center Team SAR Topography Phone: +49 8153 28 3439 Email: Anna.Wendleder@dlr.de | Markus.Breunig@dlr.de

igarss_2011_breunig_DLR_TDM_water_mask.ppt

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igarss_2011_breunig_DLR_TDM_water_mask.ppt Presentation Transcript