Synthetic Aperture Radar for Rapid Flood Extent Mapping

Transcription

1 National Aeronautics and Space Administration ARSET Applied Remote Sensing Training Synthetic Aperture Radar for Rapid Flood Extent Mapping Sang-Ho Yun ARIA Team Jet Propulsion Laboratory California Institute of Technology

2 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

3 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

4 And Half Dark At any given time, 50% of the earth is dark. National Aeronautics and Space Administration Applied Remote Sensing Training Program 4

5 Radiation Pattern Radiation pattern Antenna y U θ y x θ x National Aeronautics and Space Administration Applied Remote Sensing Training Program 5

6 Some Imaging Radar Jargon SAR antenna -3dB look angle swath footprint National Aeronautics and Space Administration Applied Remote Sensing Training Program 6

7 Synthetic Aperture Radar (SAR) Real Aperture Radar Synthetic Aperture Radar National Aeronautics and Space Administration Applied Remote Sensing Training Program 7

8 Synthetic Aperture Radar (SAR) Synthetic Aperture Radar Real Aperture Radar National Aeronautics and Space Administration Applied Remote Sensing Training Program 8

9 SAR image (amplitude) Raw data (complex) SAR processing Amplitude Phase National Aeronautics and Space Administration Applied Remote Sensing Training Program 9

10 Microwave Scattering (Smooth) λ h < λ/2 Dark National Aeronautics and Space Administration Applied Remote Sensing Training Program 10

11 Microwave Scattering (Rough) λ h < λ/2 Bright National Aeronautics and Space Administration Applied Remote Sensing Training Program 11

12 Floods Form Smooth Surface Darker National Aeronautics and Space Administration Applied Remote Sensing Training Program 12

13 Floods with Tall Vegetation Brighter National Aeronautics and Space Administration Applied Remote Sensing Training Program 13

14 Floods with Artificial Structure Brighter National Aeronautics and Space Administration Applied Remote Sensing Training Program 14

15 SAR Image (Before) ALOS ALOS-2 Operation and Data Distribution Consortium, Original Data provided by JAXA National Aeronautics and Space Administration Applied Remote Sensing Training Program 15

16 SAR Image (After) ALOS ALOS-2 Operation and Data Distribution Consortium, Original Data provided by JAXA National Aeronautics and Space Administration Applied Remote Sensing Training Program 16

17 Flood Extent Maps Derived from ALOS-2 SAR Data data compared to 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/ us_midwest_floods/ Original data provided by JAXA Applied Remote Sensing Training Program 17

18 Flood Extent Map Google Earth NASA Flood Map National Aeronautics and Space Administration Applied Remote Sensing Training Program 18

19 Flood Extent Map JAXA Flood Map NASA Flood Map National Aeronautics and Space Administration Applied Remote Sensing Training Program 19

20 SAR Data Acquisition Latency Days RADARSAT 1 (C/24) 4 ERS 2 (C/35) ERS 1 (C/35) 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) Year National Aeronautics and Space Administration Applied Remote Sensing Training Program 20

21 Summary Radar sensors see through clouds day and night. Synthetic Aperture Radar achieves high resolution (3 20 m) over a wide swath ( 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