Development of database andsimulation of vegetation BRF
Yoshiaki HONDA
CEReS, Chiba univ.

New possibilities optical sensor
Toward SGLI algorithm development• BRF of vegetation surface• BRF data will give us new information ofvegetation– Biomass– Vegetation types– Environmental change etc.

Conventional Instruments

Spherical Rail TypeTower Type

Crane Type→ Measurement
view areas
are limited.

-Autonomous Unmanned Helicopter measurement systemTo fill the above requirements , our team selected
Autonomous Unmanned helicopter (YAMAHA R-MAX) as platform.
Attitude Sensor

Measurement
mount SpaceGPS Antenna forhelicopter

Autonomous Unmanned Helicopter･High position accuracy
→DGPS
±10cm
･Acquired Attitude and GPSwith 10Hz
･Can fly up to 150m

This platform fill the requirements.

Images from RC Helicopter
2000/6/22 9:11
Montana

N46.894042°
W113.438993°

2000/6/22 9:43
Montana

N46.894439°
W113.437595°

2000/6/28 11:57
British Colombia

N48.616685°
W123.724244°

2001/8/10 10:05
Mandalgobi

N46.159850°
E106.218593°

Spectral Data

Sensor Angle and ReflectanceFor complete BRF data
• From 17 different points in principalplane• From 17 different points in vertical plane• Total 34 points• 17 minutes flight• At least 15 minutes clear sky (withoutcloud)• Realization is very rare

Calculation of Cover Ratio
2000/7/2 12:43 Oregon
N44.251292°
W122.210735°

Digital Image
from RC Helicopter

Calculationof Cover RatioReflectance and Cover Ratio

Correlation Coefficient
0.929611

Reflectance
NIR(725-850nm)

Regression Line
NIR=0.4232VCR+0.0754
RMS Error 0.013757 (4.68%)
HighCorrelation

Vegetation
Cover RatioReflectance of one Area

Cover Ratio& Reflectanceof Each Component in the View AreaReflectance of one Area

Cover Ratio& Reflectanceof Each Component in the View Area

Distribution
Map
3D Structure
・Shadow・ShadeReflectance of one Area

Cover Ratio& Reflectanceof Each Component in the View Area

Distribution
Map
3D Structure
・Shadow・ShadeDigital Image
DEM(Digital Elevation Map)

Sun Angle
Sensor Angle

Results of Estimation
Regression Line
NIR=0.4232VCR+0.0754

RMS Error : 0.051177(9.05%)

Simulation
Digital Image Sensor Angle
DEM

Sun Angle

RMS Error : 0.022056(6.83%)

BRF simulation using ray tracing
SensorPosition

ReflectanceRay-Tracing
SolarPosition

DSM

BRF
ImageShadowRate

ObjectParameter

Comparison between Simulation
data and MODIS observe data• Target area
– Kobutizawa– Needle leaf forest• Data– TERRA MODIS L1B– IFOV 500m

• Priod– ２４May - ２１July– Thick leaf priod– Cloud free

MODIS & Simulated data

MODISデータとシミュレーションデータの比較 NIR反射率

r:0.901

Condition of observation

Target condition（八ヶ岳観測サイト内カラマツ林）

altitude: 700,000m

Tree height : 22.5m tree canopy radius : 2.0m
Tree interval : 4.5m lowest branch height：6.8m

Field of view angle：0.04 degHow to get parameters• DSM– Laser scanner– Stereo pare image• Object parameters– Digital camera– Digital video– Spectral radiometer

-Autonomous Unmanned Helicopter measurement systemDeveloped measurement system using
Autonomous Unmanned helicopter
Requirements of acquired data
Laptop Computer-ImageDigital Camera-Spectral data

Spectral Meter-3D structure
Digital Video

Laser Scanner

-Autonomous Unmanned Helicopter measurement systemDeveloped measurement system using
Autonomous Unmanned helicopter

Equipment of measurement system
Digital Camera

Canon EOS-KISS

Laser ScannerSpectral meter

SICK LMS291MS-720

FormatCanon RAW formatdistance~ 80m

Number ofpixels

3072×2048pixels

resolution of angle

0.5°Hz20Hz

Focal length

35.0mmRange ofWavelength

350nm ~1080nm

-Observation of Canopy Acquired data
Heli Speed：0.5m/s
Number of flight ：6
Average of Flight time：30min
Number of distance data：3,000,000
shot images ：400

X

150m

Y100m

-Observation of Canopy Acquired data

One of acquired image
Mosaic image

-Observation of Canopy Acquired data
These are the data of the whole observation area.
Z[cm]-Observation of Canopy Acquired data
Using structure data and image, It is able to make a 3D view.

Requirement for helicopter
observation• Spectral observation– At least 5 minutes clear sky• DSM ( digital image, laser scanner )– Even cloudy sky is OK– Rainfall is no good

• Realization became easy

Conclusion
for SGLI ( GLI follow on )

Thank you for your kindattention