M.S. 1

SAR

M.S. 2

SARSAR

M.S. 3

1. SAR system

description

SAR imaging I

History1950s Airborne SAR was developed in USA1978, Seasat L-SAR, digital1980s,1990s USA, EC, Japan, Russia launched SARs2000s:ENVISAT, ALOS were launched, and RADARSAT-2,TERRA-SARX, etc,,,Feature (Advantages)•High resolution Imaging by a two dimensional correlation

several meter•Detection of amplitude and phase•Operable in night/day, weather conditions•Disadvantages•Speckle noise•Foreshortening, layover, shadowing•Interference from the ground radar•Saturation, AGC/STC, antenna pattern error

SAR model JERS-1 SAR artistic view

JERS-1 SAR

PRISMAVNIR-2

PALSAR

Data RelayAntenna

Solar Array Paddle

Star Tracker

GPS Antenna

Velocity

NadirPRISM : Panchromatic Remote-sensing

Instrument for Stereo MappingAVNIR-2: Advanced Visible and Near Infrared Radiometer type 2PALSAR: Phased Array type L-band Synthetic Aperture Radar

ALOS Satellite System

Sun SynchronousOrbit

46 days( 2 days )

Repeat Cycle(Sub-Cycle)

691.65kmAltitude

about 7kWat EOL

Generated Elec. Power

about 4,000kgSpacecraft Mass

H-IIALaunch Vehicle

Jan. 24 2006Launch Date

2.SA R imaging

STRIP mode

Signal reception by a radar

RADAR:Radio Detection and Ranging

transmit

receive

intermediate

Chirp signal case

antenna target

ft = exp 2 jf0t{ }

fr = exp 2 jf0 t2R

c

fr ft = exp 2 jf02R

c

fr ft = exp 2 jf02R

c

+ 2 j

k

2t

2R

c

2

Importance Ris remained.

SAR imaging

Sra R, x( ) = A R, x( )sin c2 Bw R R0( )

C

sin c 2

x x0

L

exp

4 R0 j

Cloud water vapor

Ionosphere

Bw LJERS-1 15M 12mPALSAR 28M 9mPALSAR 14M 9mPi-SAR 50M 1.6m

Correlation

g t '( ) = f (t) f *(t + t ' )dt/ 2

/ 2

f t( ) =t t0

/ 2

exp t t0( )

2

{ }

2 X 1 D correlation processing

SIGMA-SAR

Simulateddata

Sample images of the SCANSAR:Amazon

M.S. 13

3. SAR

3.1

3.2 DEM

M.S. 14

fd =2

u s rp( )rp rs( )rp rs

us

rp

rs

rp

GRS80

h

ERS-1/2JERS-1radarsatENVISATALOSSIR-Cradarsat2

JERS-1

M.S. 15

Doppler

-4000

-3000

-2000

-1000

0

1000

2000

3000

4000

yaw angle

M.S. 16

fd1 =2

us rp '( )rp ' rs( )rp ' rs

r = rp ' rs

xp2

Ra2

+yp

2

Ra2

+zp

2

Rb2

= 1

r =c

2n fprf + toff +

i

fsample

d =f

fdd

vg

• GRS80

•SAR

•

M.S. 17

x =fd

fdd + fd ' vg

vg

iso-Doppler line

M.S. 18

fd1 =2

us rp( )rp rs( )rp rs

r = rp rs

xp2

Ra2

+yp

2

Ra2

+zp

2

Rb2

= 1

Ra = Ra + h ,( ) + hgeoid ,( ){ } 1 e2 sin2

Rb = Ra 1 e2 sin2

e2=

Ra2 Rb

2

Ra2

hhgeoid

M.S. 19

fd1 =2

us rp'( )

rp' rs( )

rp' rs

= fd +d

dxfd dx + fdd

dx

vg

fd = fd1 fd

= fd ' dx + fdd

dx

vg

dx =fd

fdd + fd ' vg

vg

dx

fdd=-650

fd ' vg =fd

h

h

xvg

=18

400010100

6500 = 30.4%

fdd

0.4

M.S. 20

M.S. 21

6 8 m )18Hz

M.S. 22

RGB DEM

R-GG

R-G-B

M.S. 23

DEM

AR

M.S. 24

JERS-1 SAR

(PALSAR)

CR, ARC s location

Validation CR, ARCAmazon

Geometry 100 mRadiometry 1.5 dB (abs.)

1.0 dB (relative)5° (phase)

Standard Products

1.01.11.5

Landsat imagesAmazon images

GPS s positions

Geometry 100 mRadiometry 1.5 dB

5mm

Research ProductDeformationForest mapSoil moisture

Snow mapBiomassSea Ice

CR,ARC s location

GCP,DEMValidation CR,ARC

geometry 50 m (horizon)Radiometry 30 m (vertical)

1.5 dB(ext. layover)

High levelOrtho rectified

DEM

Validation methodAccuracy GoalProducts

M.S. 26

SAR JERS-1

DEM

JERS-1 m

ALOS JERS-1

M.S. 27

M.S. 28

M.S. 29

PALSAR

lat = ai, j line linec( )4 j

pixel pixelc( )4 i

j=0

4

i=0

4

+ latc

lon = bi, j line linec( )4 j

pixel pixelc( )4 i

j=0

4

i=0

4

+ lonc

pixel = ci, j lon lonc( )4 j

lat latc( )4 i

j=0

4

i=0

4

+ pixelc

line = di, j lon lonc( )4 j

lat latc( )4 i

j=0

4

i=0

4

+ linec

ai, j = facter _ m[is1+ j + i 5]

bj ,i = facter _ m[is2 + j + i 5]

cj ,i = facter _ m[is3 + j + i 5]

dj ,i = facter _ m[is4 + j + i 5]

M.S. 30

M.S. 31

M.S. 32

PALSAR Calibration

M.S. 33

M.S. 34

FBS/FBD Evaluation Results

FBD34.3

FBD41.5

FBS21.5

FBS34.3

FBS41.5

FBD FBS

M.S. 35

Geometric calibration using the CRs

Mode and time dependency over last three years

M.S. 36

Summary of the PALSAR CALVAL results

M.S. 37

M.S. 38

M.S. 39

Ortho Rectification and slope correction

Purpose:

1)correct the foreshortening and azimuth shift to co-register

with the map information

2) Additional slope correction reduces the area dependence of

the scattering coefficient mainly.

Geo error (ortho ) > Geo error (slant)

M.S. 40

Slope correction(

0=

0 sin

cos

l = cos 1rs rp( )rs rp

nl

nl =1

hx2

+ hy2

+1hx hy 1( )

t

cos = n f nl =sin l cos l hx

hx2

+ hy2

+1

M.S. 41

Correction of the local incidence dependence

IACF: Illumination area correction factor

LICF:Local Incidence angle Factor

0~ 10d l

M.S. 42

M.S. 43

M.S. 44

M.S. 45

M.S. 46

M.S. 47

M.S. 48

PALSAR