GB-SAR 시스템의 영상화 및 간섭기법GB-SAR 시스템의 영상화 및 간섭기법
이훈열, 조성준, 성낙훈이훈열, 조성준, 성낙훈
강원대학교 지구물리학과강원대학교 지구물리학과
한국지질자원연구원 지반안전연구부한국지질자원연구원 지반안전연구부
한국지구물리물리탐사학회 2007 학술대회 6월 7-8일 한국지질자원연구원
ContentsContents
IntroductionIntroduction
GB-SAR SystemGB-SAR System
SAR Focusing and InterferometrySAR Focusing and Interferometry
ApplicationsApplications
ConclusionConclusion
IntroductionIntroduction
GB-SAR: Ground-Based Synthetic Aperture RadarGB-SAR: Ground-Based Synthetic Aperture Radar
Synthetic Aperture RadarSynthetic Aperture Radar
Imaging RadarImaging Radar
Azimuth aperture synthesisAzimuth aperture synthesis
Ground-BasedGround-Based
Fairly versatile system configurationFairly versatile system configuration
Multiple frequency (L, C, X, Ku, Ka, etc)Multiple frequency (L, C, X, Ku, Ka, etc)
Full Polarization (VV, VH, HV, HH)Full Polarization (VV, VH, HV, HH)
Ultimate SAR focusingUltimate SAR focusing
Zero Doppler centroid (stationary vehicle during Tx/Rx)Zero Doppler centroid (stationary vehicle during Tx/Rx)
Accurate estimation of Doppler rate from geometryAccurate estimation of Doppler rate from geometry
Topography Mapping: Cross-Track InSAR or Delta-K InSARTopography Mapping: Cross-Track InSAR or Delta-K InSAR
Surface Motion: Zero-baseline and short atmospheric path for Temporal Coherency, DInSAR andPSInSARSurface Motion: Zero-baseline and short atmospheric path for Temporal Coherency, DInSAR andPSInSAR
Useful for new SAR concept designUseful for new SAR concept design
Previous WorksPrevious Works
LISA (EU) for Avalanche and landslide monitoringLISA (EU) for Avalanche and landslide monitoring
Other laboratory or field tests (UK, Japan)Other laboratory or field tests (UK, Japan)
GB-SAR SystemGB-SAR System
System ConfigurationSystem Configuration
SAR Focusing AlgorithmsSAR Focusing Algorithms
AlgorithmsAlgorithms
AdvantangeAdvantange
DisadvantageDisadvantage
UsageUsage
Range-Doppleror ω-kRange-Doppleror ω-k
Widely used forSARWidely used forSAR
Memoryinefficiency forpartial-focusingMemoryinefficiency forpartial-focusing
Near RangeNear Range
(full-focusing)(full-focusing)
Deramp-FFTDeramp-FFT
Efficient inmemory andCPU timeEfficient inmemory andCPU time
Distortion innear rangeDistortion innear range
Far RangeFar Range
(partial-focusing)(partial-focusing)
Time DomainTime Domain
ExacteverywhereExacteverywhere
Time consumingTime consuming
EverywhereEverywhere
DF vs RD (Indoor)DF vs RD (Indoor)
(a) DF algorithm
(b) RD algorithm
DF vs RD (outdoor)DF vs RD (outdoor)
(a) DF algorithm (2MB Memory)
(b) DF algorithm (geocoded)
(b) RD algorithm (128MB Memory)
GB-SAR ResolutionsGB-SAR Resolutions
(a) Full Focusing
(b) Partial Focusing
Range resolution:
GB-InSAR ConfigurationGB-InSAR Configuration
DInSARDInSAR
Cross-Track InSARCross-Track InSAR
Delta-K InSARDelta-K InSAR
Cross-Track andDelta-K InSARCross-Track andDelta-K InSAR
DInSAR with rangechange
Cross-Track InSAR
GB-SAR InterferometryGB-SAR Interferometry
ChangeChange
Phase DifferencePhase Difference
Range phase rampRange phase ramp
SensitivitySensitivity
DInSARDInSAR
RangeRange
nonenone
Range Range
Cross-TrackInSARCross-TrackInSAR
Vertical baselineVertical baseline
Height Height
Delta-KInSARDelta-KInSAR
Frequency shiftFrequency shift
Height Height
Cross-Track andDelta-KInSARCross-Track andDelta-KInSAR
andand
Height Height
KIGAM Roof-Top TestKIGAM Roof-Top Test
T1T1
Range:
Center frequency=5.3GHzBandwidth=200MHz
Sample=1601
Power=33dBm (2W)
Azimuth:
Scan length=5m
Step=5cm
Sample=101
T2: Temporal baseline of 20minutes(DInSAR)T2: Temporal baseline of 20minutes(DInSAR)
T3: Spatial baseline of -30cm vertical(InSAR DEM)T3: Spatial baseline of -30cm vertical(InSAR DEM)
T4: Frequency shift of -10MHz (Delta-K InSAR)T4: Frequency shift of -10MHz (Delta-K InSAR)
Image AreaImage Area
VVVV
T1
VHVH
T1
HHHH
T1
DInSAR (T2-T1)DInSAR (T2-T1)
VV
Cross-Track InSAR (T3-T2)Cross-Track InSAR (T3-T2)
VV
Delta-K InSAR (T4-T3)Delta-K InSAR (T4-T3)
VV
VV
Cross-Track and Delta-K InSAR(T4-T2)Cross-Track and Delta-K InSAR(T4-T2)
VV
VV
VV
Automatic Acquisition with 2cm Step, 2007. 3. 19 7:22pm- 4:20am, A1~A9Automatic Acquisition with 2cm Step, 2007. 3. 19 7:22pm- 4:20am, A1~A9
HH
VV
Phase ErrorsPhase Errors
Ideal Case
A6-A5, HH
Azimuth scan shift of2cm. A9-A1, HH
Range SystemShift of 2mm
PSInSAR – Temporal CoherencePSInSAR – Temporal Coherence
TC of 9 acquisitions for 2 hours.
Color scheme: black(0) to white(0.9) and blue (0.9) to red(1)
ConclusionConclusion
We made a SAR system.We made a SAR system.
A GB-SAR system was developed, tested, and waiting for applications.A GB-SAR system was developed, tested, and waiting for applications.
Optimal GB-SAR focusing algorithms were tested.Optimal GB-SAR focusing algorithms were tested.
Cross-Track and Delta-K InSAR were tested.Cross-Track and Delta-K InSAR were tested.
DInSAR or PSInSAR were tested: Phase stability of 1° (0.1mm range) wasachieved for several hours for stable reflectors, rendering phase change of10 ° meaningful (1mm range accuracy for DInSAR).DInSAR or PSInSAR were tested: Phase stability of 1° (0.1mm range) wasachieved for several hours for stable reflectors, rendering phase change of10 ° meaningful (1mm range accuracy for DInSAR).
GB-SAR can be used for various applications such as:GB-SAR can be used for various applications such as:
Safety monitoring of natural or anthropogenic structuresSafety monitoring of natural or anthropogenic structures
Microwave backscattering properties of targetMicrowave backscattering properties of target
New SAR system concept designNew SAR system concept design
More robust GB-SAR system optimized to a specific application will bedeveloped.More robust GB-SAR system optimized to a specific application will bedeveloped.
Thank YouThank You