National Aeronautics and Space Administration ARSET Applied Remote Sensing Training http://arset.gsfc.nasa.gov @NASAARSET Synthetic Aperture Radar for Rapid Flood Extent Mapping Sang-Ho Yun ARIA Team Jet Propulsion Laboratory California Institute of Technology www.nasa.gov
Atmospheric Windows & Current SAR Missions KOMPSAT-5 TerraSAR-X COSMO-SkyMed Radarsat-2 Sentinel-1A ALOS-2 X-band (3 cm) C-band (6 cm) S-band (12 cm) L-band (24 cm) γ-rays, x-rays visible infrared microwave National Aeronautics and Space Administration Applied Remote Sensing Training Program 2
Earth is Mostly Cloudy Average cloudiness over Earth in April 2015 seen from Aqua Satellite. At any given time, around 70% of the Earth is covered by clouds. National Aeronautics and Space Administration Applied Remote Sensing Training Program 3
And Half Dark At any given time, 50% of the earth is dark. National Aeronautics and Space Administration Applied Remote Sensing Training Program 4
Radiation Pattern Radiation pattern Antenna y U θ y x θ x National Aeronautics and Space Administration Applied Remote Sensing Training Program 5
Some Imaging Radar Jargon SAR antenna -3dB look angle swath footprint National Aeronautics and Space Administration Applied Remote Sensing Training Program 6
Synthetic Aperture Radar (SAR) Real Aperture Radar Synthetic Aperture Radar National Aeronautics and Space Administration Applied Remote Sensing Training Program 7
Synthetic Aperture Radar (SAR) Synthetic Aperture Radar Real Aperture Radar National Aeronautics and Space Administration Applied Remote Sensing Training Program 8
SAR image (amplitude) Raw data (complex) SAR processing Amplitude Phase National Aeronautics and Space Administration Applied Remote Sensing Training Program 9
Microwave Scattering (Smooth) λ h < λ/2 Dark National Aeronautics and Space Administration Applied Remote Sensing Training Program 10
Microwave Scattering (Rough) λ h < λ/2 Bright National Aeronautics and Space Administration Applied Remote Sensing Training Program 11
Floods Form Smooth Surface Darker National Aeronautics and Space Administration Applied Remote Sensing Training Program 12
Floods with Tall Vegetation Brighter National Aeronautics and Space Administration Applied Remote Sensing Training Program 13
Floods with Artificial Structure Brighter National Aeronautics and Space Administration Applied Remote Sensing Training Program 14
SAR Image (Before) ALOS-2 2015-09-30 ALOS-2 Operation and Data Distribution Consortium, Original Data provided by JAXA National Aeronautics and Space Administration Applied Remote Sensing Training Program 15
SAR Image (After) ALOS-2 2016-01-06 ALOS-2 Operation and Data Distribution Consortium, Original Data provided by JAXA National Aeronautics and Space Administration Applied Remote Sensing Training Program 16
Flood Extent Maps Derived from ALOS-2 SAR Data 2016-01-06 data compared to 2015-09-30 Processing Level: 1.5 Coverage: 70 km x 240 km ResoluIon: ~12 m Area of potenial floods: Blue + Red Blue polygons: Floods with smooth surface Red polygons: Floods with tall vegetaion National Aeronautics and Space Administration Product formats KMZ (Polygons) KMZ (PNG image) GeoTiff Shapefile Available to download at h_p://aria-share.jpl.nasa.gov/ events/20160111us_midwest_floods/ Original data provided by JAXA Applied Remote Sensing Training Program 17
Flood Extent Map Google Earth NASA Flood Map National Aeronautics and Space Administration Applied Remote Sensing Training Program 18
Flood Extent Map JAXA Flood Map NASA Flood Map National Aeronautics and Space Administration Applied Remote Sensing Training Program 19
SAR Data Acquisition Latency Days 8 7 6 5 RADARSAT 1 (C/24) 4 ERS 2 (C/35) ERS 1 (C/35) 3 2 1 L - band S - band Envisat (C/35) C - band X - band ALOS 1 (L/46) RADARSAT 2 (C/24) Tandem L 2 (L/8) Tandem L 1 (L/8) SAOCOM 1B (L/16) SAOCOM 1A (L/16) ALOS 3 (L/14) ALOS 2 (L/14) NISAR (LS/12) RADARSAT Constellation 3 (C/12) RADARSAT Constellation 2 (C/12) RADARSAT Constellation 1 (C/12) Sentinel 1D (C/12) Sentinel 1C (C/12) Sentinel 1B (C/12) Sentinel 1A (C/12) Envisat ext (C/30) COSMO SkyMed Sec. Gen. 2 (X/16) COSMO SkyMed Sec. Gen. 1 (X/16) COSMO SkyMed 4 (X/16) COSMO SkyMed 3 (X/16) COSMO SkyMed 2 (X/16) COSMO SkyMed 1 (X/16) KOMPSAT 6 (X/28) KOMPSAT 5 (X/28) HRWS (X/11) TerraSAR X Next Gen. (X/11) PAZ (X/11) TanDEM X (X/11) TerraSAR X (X/11) 0 1993 1998 2004 2009 2015 2020 Year National Aeronautics and Space Administration Applied Remote Sensing Training Program 20
Summary Radar sensors see through clouds day and night. Synthetic Aperture Radar achieves high resolution (3 20 m) over a wide swath (50 250 km). SAR amplitude is sensitive to floods, with pixel values becoming either darker or brighter. Achievable SAR data acquisition latency is already less than a day Copyright 2016 California Institute of Technology. Government sponsorship acknowledged. National Aeronautics and Space Administration Applied Remote Sensing Training Program 21