open sar toolkit (ost)eoopenscience.esa.int/files/presentation213.pdflightning talk on sepal today:...
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ESA UNCLASSIFIED - For Official Use
Open SAR Toolkit (OST)The simple way of processing SAR data for Land Applications
Andreas Vollrath, Erik Lindquist & Daniel Wiell
27.09.2017
ESA UNCLASSIFIED - For Official Use Vollrath et al. | ESRIN | 27/09/2017 | Slide 2
• based on free and open source software components• provide easy access to freely available SAR datasets• allow non-SAR experts to pre-process SAR data• automatized routines to produce analysis ready data• provide additional information on SAR remote sensing
What is the Open SAR Toolkit?
NOTE:Lightning talk on SepalToday: 17:39
ESA UNCLASSIFIED - For Official Use Vollrath et al. | ESRIN | 27/09/2017 | Slide 3
1. Based on top of:• SNAP (SAR related operations)• GDAL, python, R (GIS functionalities)
• Orfeo (mosaicking)
2. Accessibility• GUI (R-Shiny)• CLI (bash)
3. Runs on:• Linux (natively, developed on Ubuntu 16.04)• Mac OS, Windows 10 (via docker, not widely tested yet)
Design & Concept
ESA UNCLASSIFIED - For Official Use Vollrath et al. | ESRIN | 27/09/2017 | Slide 4
1. Sentinel-1• search and download for all kind of S1 products
2. ALOS Kyoto & Carbon mosaics• ease access to ftp server• free for non-commercial use• yearly global mosaics (25 m resolution)
• JERS-1: 1996• ALOS PALSAR-1: 2007, 2008, 2009, 2010• ALOS PALSAR-2: 2015, 2016, ongoing
Easy access
ESA UNCLASSIFIED - For Official Use Vollrath et al. | ESRIN | 27/09/2017 | Slide 5
1. Download by:• AOI Shapefile• Country boundaries
2. Processing:• Mosaicking of tiles• HH/HV ratio and RFDI creation• Shapefile with acquisition dates• Layover/Shadow mask• Speckle filter (optional)
ALOS K&C mosaics
ESA UNCLASSIFIED - For Official Use Vollrath et al. | ESRIN | 27/09/2017 | Slide 6
1. Search by:• AOI Shapefile• Country boundaries
2. Refinement by:• OST inventory shapefile• contains relevant information on acquisitions
3. Download by:• OST inventory shapefile• Predefined folder structure for subsequent
bulk processing
Sentinel-1
ESA UNCLASSIFIED - For Official Use Vollrath et al. | ESRIN | 27/09/2017 | Slide 7
1. Supported Products for processing:• Interferometric WS mode• VV & VV/VH polarization• Level-1 GRD
2. Automatized Processors:• 1a: GRD to GTC• 1b: GRD to RTC• 2: Time-series preparation• 3: Timescan composites• 4: Mosaicking
Sentinel-1
ESA UNCLASSIFIED - For Official Use Vollrath et al. | ESRIN | 27/09/2017 | Slide 8
1. Supported Products for processing:• Interferometric WS mode• VV & VV/VH polarization• Level-1 GRD
2. Automatized Processors:• 1a: GRD to GTC• 1b: GRD to RTC• 2: Time-series preparation• 3: Timescan composites• 4: Mosaicking
Sentinel-1
ESA UNCLASSIFIED - For Official Use Vollrath et al. | ESRIN | 27/09/2017 | Slide 9
GRD to RTC processorSingle images Time-series preparation
Sentinel-1
ESA UNCLASSIFIED - For Official Use Vollrath et al. | ESRIN | 27/09/2017 | Slide 10
GRD to RTC processorSingle images Time-series preparation
Sentinel-1
ESA UNCLASSIFIED - For Official Use Vollrath et al. | ESRIN | 27/09/2017 | Slide 11
Time-series processor
Sentinel-1
ESA UNCLASSIFIED - For Official Use Vollrath et al. | ESRIN | 27/09/2017 | Slide 12
Time-series processorExample: Bolivia (VV-pol)• co-registered• same extent and
resolution• temporal dynamics• disturbances by heavy
rainfall
Sentinel-1
ESA UNCLASSIFIED - For Official Use Vollrath et al. | ESRIN | 27/09/2017 | Slide 13
Timescan processor• Calculate basic descriptive statistics in time• Mean, Min, Max, SD, CoV• Advantages:
• Reduction in storage needs• Reduction of noise / enhance information• Capture temporal dynamics
Sentinel-1
ESA UNCLASSIFIED - For Official Use Vollrath et al. | ESRIN | 27/09/2017 | Slide 14
Example single-pol (VV)Bolivia Timescan composite• 22 acquisitions per swath• Timescan composite
• Red: VV-max• Green: VV-min• Blue: VV-SD
• Temporal dynamics related to Land cover:
• Urban, Forest --> stable• Bare, Agric. --> dynamic
Sentinel-1
ESA UNCLASSIFIED - For Official Use Vollrath et al. | ESRIN | 27/09/2017 | Slide 15
Temporal Outlier removalIssues with heavy rainfall events
Sentinel-1
ESA UNCLASSIFIED - For Official Use Vollrath et al. | ESRIN | 27/09/2017 | Slide 16
Temporal Outlier removalIssues with heavy rainfall events (TRMM data overlay)
Sentinel-1
ESA UNCLASSIFIED - For Official Use Vollrath et al. | ESRIN | 27/09/2017 | Slide 17
Temporal Outlier removalTimescan creation without (left) and with (right) outlier removal
Sentinel-1
ESA UNCLASSIFIED - For Official Use Vollrath et al. | ESRIN | 27/09/2017 | Slide 18
MosaickingTime-series• Mosaicking of 8 swaths• Standard RGB
composites of Ethiopia• Red: VV• Green: VH• Blue: VV/VH
• with new 12 day repeat global: large-scale, bi-weekly mosaics possible
Sentinel-1
ESA UNCLASSIFIED - For Official Use Vollrath et al. | ESRIN | 27/09/2017 | Slide 20
MosaickingTimescan• Dual-pol composite
(VV & VH)• Red: VV-min• Green: VH-min• Blue: VH-SD
• 7 acq. per 8 swaths• Includes info from
about 310 scenes• 30 m resolution
(63677 x 46161 pixels per band)
Sentinel-1
ESA UNCLASSIFIED - For Official Use Vollrath et al. | ESRIN | 27/09/2017 | Slide 21
Multi-Sensor Integration
Future
Cloud-free spectral Temporal/Structural Structural
Landsat 8 best pixel composite / False Color
Sentinel-1 Timescan ALOS K&C (JAXA courtesy)
ESA UNCLASSIFIED - For Official Use
Thank you!
Contact: [email protected] code: https://github.com/openforis/opensarkit