Pi-SAR was developed jointly by NICT (National Information & Communication Agency) and JAXA (Japan Aerospace Exploration Agency), consisting of two X-band radomes and a single L-band radome. the X-band main radome consists of two antennas. The first antenna is used for H-polarization and the second antenna for V-polarization. The sub-radome was not used for the Naruto data collection. The two antennas inside the first radome is separated by d=20cm, and therefore polarimetric interferometric analysis can be made. It is not, however, full Pol-InSAR, because we only have HH1, HV1, and VV2 data.
CLASSIFICATION OF TYPHOON-DESTROYED FORESTS BASED ON TREE HEIGHT CHANGE DETECTION USING INSAR TECHNOLOGY.ppt
Classification of Typhoon-Destroyed Forests Based on Tree Height Change Detection Using InSAR Technology IGARSS 2011 Haipeng Wang 1 , Kazuo Ouchi 2 , and Ya-Qiu Jin 1 1. Key Laboratory of Wave Scattering and Remote Sensing Fudan University, P.R. China. 2. Department of Computer Science National Defense Academy of Japan, Japan.
<ul><li>The final goal is to establish methodology to estimate the parameters of </li></ul><ul><li>forests from high-resolution SAR data. </li></ul><ul><li>This first study we carried out is to quantify the relation between </li></ul><ul><li>high-resolution polarimetric SAR data and tree biomass of forests. </li></ul><ul><li>This second one is to extract the information of typhoon-damaged forests. </li></ul><ul><li>The methodology is to utilize the texture information, polarimetric analysis </li></ul><ul><li>and interferometric technique. </li></ul><ul><li>The test site is the Tomakomai forests in Hokkaido, Japan. </li></ul><ul><li>The SAR data were collected using the airborne Pi-SAR. </li></ul>Purpose of T his S tudy
Tomakomai National Forests Shikotsu Lake Larch Todo Fir Red Pine Spruce
Pi-SAR Pi-SAR ( P olarimetric i nterferometric - SAR ) is an airborne SAR developed jointly by NICT (National Institute of Information and Communications Technology) and JAXA (Japan Aerospace Exploration Agency). It is equipped with two X-band antennas (frequency 9.55 GHz, wavelength 3.14 cm) and a L-band antenna operating at frequency 1.27 GHz (wavelength 23.6 cm). The nominal resolution is 1.5 x 1.5 m at X-band, and 3 x 3 m at L-band for 4-look azimuth multilooking. L-band antenna X-band main antenna X-band sub-antenna
Pi-SAR Data JAXA/NICT L-band colour composite polarimetric Pi-SAR image azimuth range study area Shikotsu Lake Tomakomai City Tarumae Mt. study area Data acquired:7 th , November, 2002 Data acquired:3rd, November, 2004 azimuth range
Ground-Truth Biomass Data Collection Field measurements were made in 2002, 2003, 2005, and in 2006. Tree species, height, DBH (Diameter at Breast Height), basal area, soil moisture were measured within a 20 x 20 m sample area in each stands, and converted to above-ground biomass using the conversion formula provided by Project department (Stand volume table -East Japan-, Japan Forestry Investigation Committee. Tokyo: Forestry Agency, Oct. 1998)
Typhoon Songda Typhoon Songda (Japanese No.18) Duration:August 28 – September 8 Typhoon Songda killed 20 people and injured 700 others in Japan. In addition, 15 crew members of a vessel were reported missing. Damages from the storm amounted to $7.17 billion (2004 USD) Time arrived at Tomakomai: September 7th, 2004
Scattering Mechanisms From Forests sc attering from crown parts surface scattering from ground multiple reflection betw een ground and tree trunks/branches multiple/volume scattering from branches X/C-bands L/P-bands
Scattering Mechanism Analysis Result Accuracy:77.7%
Pi-SAR L-band antenna X-band main antenna X-band sub-antenna Pi-SAR on Gulf Stream II X-band and L-band radomes Two antennas within X-band main radome Partial Pol-InSAR by X-band main radome (Sub-antenna data not acquired this time)
Pi-SAR Data for Interferometric Analysis X-band VM Pi-SAR image Data acquired:3 rd , August, 2004 Data acquired:3rd, November, 2004
M , N —— Moving window size S —— Data Complex Interferogram Complex Degree of Coherence
Conclusions and Future Work Research was carried out to extract information of typhoo-damaged forests. The accuracies of 64.1% and 77.7% were obtained for amplitude and decomposition data respectively. InSAR processing resutls show it’s potential, but there is no quantitative results yet. Phase unwrapping: other approaches rather than the branch cut. Difficult to see the difference of typhoon-damaged information from the coherence data before and after the typhoon. Next step is to exam the coherence before and after the typhoon Fusion of optical data and SAR data: QuickBird, IKONOS, Geoeye multispectrum optical data, Pi-SAR I&II data.