Motomasa Daigo

A new vegetation index based on the universal pattern decomposition method

This study examined a new vegetation index, based on the universal pattern decomposition method (VIUPD). The universal pattern decomposition method (UPDM) allows for sensor‐independent spectral analysis. Each pixel is expressed as the linear sum of standard spectral patterns for water, vegetation and soil, with supplementary patterns included when necessary. Pattern decomposition coefficients for each pixel contain almost all the sensor‐derived information, while having the benefit of sensor independence. The VIUPD is expressed as a linear sum of the pattern decomposition coefficients; thus, the VIUPD is a sensor‐independent index. Here, the VIUPD was used to examine vegetation amounts and degree of terrestrial vegetation vigor; VIUPD results were compared with results by the normalized difference vegetation index (NDVI), an enhanced vegetation index (EVI) and a conventional vegetation index based on pattern decomposition (VIPD). The results showed that the VIUPD reflects vegetation and vegetation activity more sensitively than the NDVI and EVI. Present address: Institute of Remote Sensing and Geographical Information System, Peking University, Beijing, 100871, China. Present address: Laboratory of Nature Information Science, Department of Information and Computer Sciences, Nara Industrial University, Nara, Japan.

Double-sided microstrip sensor for the barrel of the SDC silicon tracker

Abstract A full-size prototype microstrip sensor for the silicon tracker of the SDC detector to be used at the Superconducting Super Collider has been fabricated at Hamamatsu Photonics. The sensor is double-sided, using an AC-coupled readout with 50 μm pitch strips. The sensor size is 3.4 × 6.0 cm 2 . Polycrystalline silicon is used as a bias feeding resistor on both surfaces. Each ohmic strip is isolated by a p + blocking line. The detailed requirements for the silicon tracker and the corresponding specifications as well as how to achieve them are discussed. The static performances of this prototype sensor are presented.

Sensor‐independent analysis method for hyperspectral data based on the pattern decomposition method

This paper describes a modified pattern decomposition method with a supplementary pattern. The proposed approach can be regarded either as a type of spectral mixing analysis or as a kind of multivariate analysis; the later explanation is more suitable considering the presence of the additional supplementary patterns. The sensor‐independent method developed herein uses the same normalized spectral patterns for any sensor: fixed multi‐band (1260 bands) spectra serve as the universal standard spectral patterns. The resulting pattern decomposition coefficients showed sensor independence. That is, regardless of sensor, the three coefficients had nearly the same values for the same samples. The estimation errors for pattern decomposition coefficients depended on the sensor used. The estimation errors for Landsat/MSS and ALOS/AVNIR‐2 were larger than those of Landsat/TM (ETM+), Terra/MODIS and ADEOS‐II/GLI. The latter three sensors had negligibly small errors.

Measurement of the proton-antiproton pair production from two-photon collisions at TRISTAN

Abstract The cross section of the γγ → p p reaction was measured at two-photon center-of-mass energy (Wγγ) between 2.2 and 3.3 GeV, using the two-photon process at an e+e− collider, TRISTAN. The Wγγ dependence of the cross section integrated over a c.m. angular region of | cos θ ∗ | is in good agreement with the previous measurements and the theoreticalv prediction based on diquark model in the high Wγγ region.

High proton polarization in crystalline naphthalene by dynamic nuclear polarization with laser excitation at room temperature and liquid nitrogen temperature

Abstract We have successfully polarized protons in naphthalene doped with pentacene at room temperature and liquid nitrogen temperature. Pentacene molecules have been excited with a laser beam and protons have been polarized dynamically in the triplet state of pentacene. We have obtained a polarization of about 13% at liquid nitrogen temperature in a field of about 3 kG with an N2 laser of about 150 mW. We expect to obtain a polarization higher than 30% with another type of laser.

Assessment of the universal pattern decomposition method using MODIS and ETM data

The universal pattern decomposition method (UPDM) is a sensor‐independent method in which each satellite pixel is expressed as the linear sum of fixed, standard spectral patterns for water, vegetation and soil. The same normalized spectral patterns can be used for different solar‐reflected spectral satellite sensors. Supplementary patterns are included when necessary. The UPDM has been applied successfully to simulated data for Landsat/ETM+, Terra/MODIS, ADEOS‐II/GLI and 92‐band CONTINUE sensors using ground‐measured data. This study validates the UPDM using MODIS and ETM+ data acquired over the Three Gorges region of China. The reduced χ2 values for selected area D, that with the smallest terrain influences, are 0.000409 (MODIS) and 0.000181 (ETM+), and the average linear regression factor between MODIS and ETM+ is 1.0077, with root mean square (rms) value 0.0082. The linear regression factor for the vegetation index based on the UPDM (VIUPD) between MODIS and ETM+ data for area D is 1.0089 with rms 0.0696. Both UPDM coefficients and VIUPD are sensor independent for the above sensors.

A Vegetation Index to Estimate Terrestrial Gross Primary Production Capacity for the Global Change Observation Mission-Climate (GCOM-C)/Second-Generation Global Imager (SGLI) Satellite Sensor

To estimate global gross primary production (GPP), which is an important parameter for studies of vegetation productivity and the carbon cycle, satellite data are useful. In 2014, the Japan Aerospace Exploration Agency (JAXA) plans to launch the Global Change Observation Mission-Climate (GCOM-C) satellite carrying the second-generation global imager (SGLI). The data obtained will be used to estimate global GPP. The rate of photosynthesis depends on photosynthesis reduction and photosynthetic capacity, which is the maximum photosynthetic velocity at light saturation under adequate environmental conditions. Photosynthesis reduction is influenced by weather conditions, and photosynthetic capacity is influenced by chlorophyll and RuBisCo content. To develop the GPP estimation algorithm, we focus on photosynthetic capacity because chlorophyll content can be detected by optical sensors. We hypothesized that the maximum rate of low-stress GPP (called “GPP capacity”) is mainly dependent on the chlorophyll content that can be detected by a vegetation index (VI). The objective of this study was to select an appropriate VI with which to estimate global GPP capacity with the GCOM-C/SGLI. We analyzed reflectance data to select the VI that has the best linear correlation with chlorophyll content at the leaf scale and with GPP capacity at canopy and satellite scales. At the satellite scale, flux data of seven dominant plant functional types and reflectance data obtained by the Moderate-resolution Imaging Spectroradiometer (MODIS) were used because SGLI data were not available. The results indicated that the green chlorophyll index, CIgreen(ρNIR/ρgreen-1), had a strong linear correlation with chlorophyll content at the leaf scale (R2 = 0.87, p < 0.001) and with GPP capacity at the canopy (R2 = 0.78, p < 0.001) and satellite scales (R2 = 0.72, p < 0.01). Therefore, CIgreen is a robust and suitable vegetation index for estimating global GPP capacity.

Time-of-Flight Counters for VENUS Detector

A time-of-flight counter system has been installed in the VENUS detector of the TRISTAN experiment at KEK. A time resolution of about 200 ps was obtained for a long scintillator of 466 cm. The system is being successfully operated in experiments.

Beam tests of a double-sided silicon strip detector with fast binary readout electronics before and after proton-irradiation

Abstract A double-sided silicon strip detector with a radiation-tolerant design was fabricated and characterized in a sequence of beam tests at KEK using 4 GeV/ c pions. The detectors were combined with newly designed, fast, lower power, bipolar amplifier-shaper-discriminator chips and CMOS digital pipeline chips to record hit-no hit signals in the strips. Efficiencies, noise occupancies, and spatial resolutions were measured before and after the proton irradiation at an equivalent fluence of 1 × 10 14 p/cm 2 , depending on angle of track incidence and strip-pitches. The median pulse height distribution, derived from the threshold scans of the efficiency, allowed to extract the response of the detector. A 1 T magnetic field enabled us to determine the Hall mobilities of electrons and holes.

Radiation effects of double-sided silicon strip sensors

Abstract A series of proton-beam irradiations was performed in order to investigate the radiation damage of silicon photodiodes and double-sided silicon strip sensors. Measurements were made for the leakage current, bias resistance, interstrip isolation, annealing and responses to an infrared light pulse and β-rays. Some problems in the production of radiation-hard double-sided strip sensors were observed. However, it has been shown that most of them can be resolved by adequately designing the strip structure, the implantation density and the materials used for various parts of the sensor. It is therefore possible to obtain a double-sided silicon strip sensor which works even after charged-particle irradiation of 20 kGy.