RADAR for Biomass Mapping

Transcription

1 RADAR for Biomass Mapping Josef Kellndorfer Wayne Walker, Katie Kirsch, Greg Fiske The Woods Hole Research Center GOFC-GOLD Biomass Workshop Missoula, 15-June-2009

2 Outline Some Radar principles Measurements and Methods for biomass retrieval with radar Current and Planned SAR Missions The U.S. National Biomass and Carbon Dataset 2000: Example of large scale biomass mapping involving radar 15-Jun-09 Josef Kellndorfer, Biomass Workshop, Missoula 2

3 EM Spectrum for Imaging Radar 15-Jun-09 Josef Kellndorfer, Biomass Workshop, Missoula 3

4 Radar imaging is cloud-penetrating All-weather mapping capability Waterford Ireland 9-Aug-1991 ERS: am, Landsat 10:43 am Courtesy: ESA 15-Jun-09 Josef Kellndorfer, Biomass Workshop, Missoula 4

5 Review of Radar Remote Sensing Role of Frequency From: Manual of Remote Sensing Third Edition, Vol 2 15-Jun-09 Josef Kellndorfer, Biomass Workshop, Missoula 5

6 Review of Radar Remote Sensing Role of Polarization C = Crown T = Trunk C C Radar Scattering Intensity Short Wave T T C T C Long Wave T 15-Jun-09 Josef Kellndorfer, Biomass Workshop, Missoula 6

7 Scattering Mechanisms in Vegetation The radar illuminates the vegetation with microwave energy (at an angle) that interacts with vegetation structure and ground in a way that is related to above ground biomass. 15-Jun-09 Josef Kellndorfer, Biomass Workshop, Missoula 7

8 Synthetic Aperture Radar To achieve high resolution from space, a large radar antenna size needs to be synthesized Image formation is typically performed through Doppler range processing Leads to speckle effects 15-Jun-09 Josef Kellndorfer, Biomass Workshop, Missoula 8

9 What is Radar Interferometry anyway? It s s simple trigonometry Surface 15-Jun-09 Josef Kellndorfer, Biomass Workshop, Missoula 9

10 Measurements for Biomass Retrieval with Radar Aboveground Biomass: SAR Backscatter measurements Single and multi-frequency SAR Single and mutli-polarization SAR Interferometric Measurements Coherence measurements Interferometric height retrieval Polarimetric interferometry (PolInSAR) Multi-baseline interferometry SAR tomography Belowground biomass: Ground penetrating radar backscatter 15-Jun-09 Josef Kellndorfer, Biomass Workshop, Missoula 10

11 Biomass Retrieval Methods with Radar Regression models Biomass = a e b(sigma-0, coherence, ) Semi-Emperical models Combining radiative transfer models with biomass- backscatter calibration Macro-ecology modeling Statistically based estimation models Bayesian MLE Ensemble learning regression trees Fusion of radar-based forest change measurements into emissions models 15-Jun-09 Josef Kellndorfer, Biomass Workshop, Missoula 11

12 Current and Planned SAR Satellites ESA Biomass Mission U.S. DESDynI (Radar/ Lidar) Brazil/Chiina CBERSAR Japan - ALOS Follow-on (2012?) Source: ASPRS 2/12/08 Argentina 15-Jun-09 Josef Kellndorfer, Biomass Workshop, Missoula 12

13 A Global Mission: The Shuttle Radar Topography Mission Flown in February 2000 during mission STS-99 on Space Shuttle Endeavor First mission of its kind using radar interferometry Covered 119 million square kilometers in 11 days Goal: Best global 3-D data set of Earth 15-Jun-09 Josef Kellndorfer, Biomass Workshop, Missoula 13

14 SRTM Vegetation Response Mean Mean Canopy Canopy Height Height Mean Mean Scattering Radar Phase Center Measured Height Height A fundamental law of science applies to the SRTM data: One scientist s noise is another scientist s signal! Ground Surface Elevation SRTM Resolution Cell 15-Jun-09 Josef Kellndorfer, Biomass Workshop, Missoula 14

15 SRTM Vegetation Height Retrieval 22.5 Mean Observed Stand Height [m] h can = * h spc Adjusted r 2 = 0.86, n = 12 h can = * h spc Adjusted r 2 = 0.79, n = 15 Samples Averaged >= 50 Samples Averaged >= 20 Samples Averaged >= 50 Samples Averaged >= SRTM Scattering Phase Center Height [m] Kellndorfer, J.M., W.S. Walker and L.E. Pierce, M.C Dobson, J. Fites,, C. Hunsaker,, J. Vona, M. Clutter, "Vegetation" height derivation from Shuttle Radar Topography Mission and National Elevation data sets." " Remote Sensing of Environment, Vol. 93, No. 3, , Jun-09 Josef Kellndorfer, Biomass Workshop, Missoula 15

16 Principal Investigator: Josef Kellndorfer Woods Hole Research Center Research Team: Wayne Walker, Katie Kirsch, Greg Fiske Woods Hole Research Center Elizabeth LaPoint, Mike Hoppus, Jim Westfall USDA Forest Service FIA Program: Four year project to produce -Forest vegetation height -Biomass and -Carbon Estimates -Conterminous U.S. -First attempt at 30 m resolution ever Collaboration: Dean Gesch,, National Elevation Dataset, USGS Collin Homer,, National Land Cover Database 2001 / MRLC, USGS Zhi-Liang Zhu,, LANDFIRE, USGS Funding and Support: NASA Terrestrial Ecology Program LANDFIRE PCI Geomatics Definiens Imaging/eCognition 15-Jun-09 Josef Kellndorfer, Biomass Workshop, Missoula 16

17 Validation Predicted Biomass Regression Tree Modeling Response Variables FIA Data Height Biomass Biomass Predictor Layers Height Predictor Layers Predicted Height MRLC Landsat Tasseled Cap NLCD 2001 Canopy Density NLCD 2001 Land Cover Slope NED Elevation SRTM - NED 15-Jun-09 Josef Kellndorfer, Biomass Workshop, Missoula 17

18 NBCD Basal-Area Weighted Height 15-Jun-09 Josef Kellndorfer, Biomass Workshop, Missoula 18

19 NBCD Aboveground Live Biomass 15-Jun-09 Josef Kellndorfer, Biomass Workshop, Missoula 19

20 Comparison with other Approaches What is the truth? 15-Jun-09 Josef Kellndorfer, Biomass Workshop, Missoula 20

21 The ALOS Satellite Launched by JAXA January on 24 th 2006 Three sensors: PRISM, AVNIR-2 and PALSAR PALSAR: First polarimetric L-band sensor on free-flying Earth RS satellite (PALSAR = Phased Array L-band SAR) 15-Jun-09 Josef Kellndorfer, Biomass Workshop, Missoula 21

22 ALOS PALSAR Observation Plan Fine Beam Mode HH/HV HH Polarimetric 15-Jun-09 Josef Kellndorfer, Biomass Workshop, Missoula 22

23 Pan-Tropical FBD Data Set Baseline: 2007 FBD Data, Gaps filled with 2008 Data (15,000 FBD Frames) Yellow: First target area currently ordered, 5,500 Frames Green: Remaining data, 9,500 Frames 15-Jun-09 Josef Kellndorfer, Biomass Workshop, Missoula 23

24 Pan-Tropical ALOS Mapping: Status 06/09 15-Jun-09 Josef Kellndorfer, Biomass Workshop, Missoula 24

25 ALOS/ PALSAR Radar Image Mosaic of the Xingu Watershed Data Acquistion: 6/8-7/ Number of Scenes: 116 Spacing: 25 m 15-Jun-09 Josef Kellndorfer, Biomass Workshop, Missoula 25

26 1996 JERS Image 15-Jun-09 Josef Kellndorfer, Biomass Workshop, Missoula 26

27 2006 ALOS-PALSAR Image

28 Color Composite Image (R-G-B = JERS-ALOS-Difference) 15-Jun-09 Josef Kellndorfer, Biomass Workshop, Missoula 28

29 Forest Cover Change Map Recent Logging 15-Jun-09 Josef Kellndorfer, Biomass Workshop, Missoula 29

30 Conclusion Advances in recent years in radar remote sensing Processing largely solved Global DEM data available for orthorectification and radiometric correction ALOS is the first L-Band multi-polarimetric operational free-flyer ALOS-2 is approved Continuation of operational C-Band missions (Radarsat,, Sentinel) Tandem-X will provide single-pass interferometric data similar to SRTM Biomass missions on the horizon: BIOMASS (ESA), DESDynI (NASA) 15-Jun-09 Josef Kellndorfer, Biomass Workshop, Missoula 30

31 Forest Visualization NBCD Height Data THANK YOU! 15-Jun-09 Josef Kellndorfer, Biomass Workshop, Missoula 31