COMMISSION F : Wave Propagation and Remote Sensing
F1.1 Terrestrial Fixed Radio Systems
Active studies of rain attenuation characteristics are continuing for developing broadband systems above quasi-millimeter wave band. It is based on a trend that the use of microwave band has been changing gradually from the fixed use to the mobile use. Results of those studies will be reflected in developing a multipoint-to-multipoint system, a mesh type wireless network system, a point to multipoint system, and a fixed wireless access system (FWA). In addition to the FWA in a millimeter wave band, FWA systems in UHF band and microwave band have become the object of propagation research.
A. Effects of Rain
Using KIT (Kitami Institute of Technology) databank that contains different integration time rain rate data sets from 54 locations in 23 countries, a new prediction method for the worldwide rain attenuation distribution on terrestrial link is proposed [Ito and Hosoya, 2002, 2004a]. This new method uses the M distribution (simplified Moupfouma distribution) and the rain rate spatial correlation, in which regional climatic parameters such as the thunderstorm ratio are considered. This new method was compared with Rec. ITU-R P.530-8 method that is currently used as the worldwide standard prediction method. From the results, it is shown that significant improvements to existing methods are obtained by this newly proposed prediction method.
Effects of the regional
climatic parameters on Lavergnat-Gole Conversion Method were analyzed, and the
result was incorporated into the extension of this method for the worldwide
application by using KIT databank [Ito and Hosoya, 2004b]. It was found that a
good accuracy in worldwide rain rate conversion could be obtained by using
regional climatic parameters such as thunderstorm ratio and so on, and it was
proved that this model could be expanded to arbitrary integration times and
regions. Moreover, the analysis using this method in
An investigation of a highly accurate method for estimating the one-minute rain rate distribution for various locations throughout Japan using observed precipitation data collected through the Automated Meteorological Data Acquisition System (AMeDAS) is reported [Akimoto et al., 2003a, 2003b]. The method estimates the one-minute rain rate distribution by supplementing the hourly rainfall data with 10-minute rainfall data and shows quantitatively an improvement in the accuracy over existing estimation methods.
Based on the experimental data of rain
attenuation on 3 links at 15 GHz and on 2 links at 22 GHz, and of rain rate at
4 locations in Tokyo urban area, the accumulated number of events of given
duration with rain rate or rain fade exceeding specific level are mainly
investigated [Ishida et al., 2003]. And these data are compared with RAL model
on rain duration and their results obtained in
For realizing Gigabit millimeter wave
broadband wireless access systems using 32 GHz band, propagation tests are
conducted on three converging links of about 2km path length and the rain rate
are measured at 10 locations in
B. Effects of Vegetation
Experimental results of the attenuation through vegetation by using quasi-millimeter wave band FWA system are reported [Ohmoto and Takahashi, 2004]. Excess losses and bit error rate (BER) are measured through several species of trees. The effect of wind is also examined. The impact of the attenuation through vegetation on the FWA system performance is also considered from the viewpoint of probability distribution of the excess loss.
C. Effects of Multipath (Residential/Urban Environment)
A method of estimating the intensity of delayed components using a radar cross-section Ð based on measured delay profiles in 5-GHz and 25-GHz bands in residential area is reported [Yamada, W. et al., 2003]. The relationship between Ð and the path length of the delayed component exhibits a less remarkable dependency on the frequency band. Common estimation method can be applied to both the 25-GHz and 5-GHz bands. The arrival probability of the delayed components for the path length is also studied. The results show that the probability density distribution of delayed components on the path length can be assumed as a Rayleigh distribution in both the 5-GHz and 25-GHz bands.
A 2 dimensional multi-building model and a prediction way of path loss and delay spread characteristics in entrance radio links by using ray-tracing calculation method are presented [Taga, 2002a]. As a result, when the clearance factor for the first Fresnel zone along direct path is more than 5m, the path loss can be taken into account as free space loss; smaller clearance values yield average excess loss values of several dB, and the path loss increases strongly at negative clearance values. These results agree very well with the experimental results.
F1.2 Satellite Radio System
A. Effects of Rain
Earth-space path in both Ku and Ka band are
still important objects for propagation studies. Several propagation measurements
have been carried out also in a tropical area in addition to the inland of
The rain attenuation measurements are
simultaneously performed for both up and down links of the Ku-band satellite
(Superbird C), which connects the Equatorial Atmospheric Radar (EAR) in
attenuation at three different locations about 100 km far away from each other
attenuation in the 12-GHz and the 21-GHz bands for
B. Effects of Other Factors
For high-data rate satellite communications, the bit error rate in Ka-band was calculated under the arrival-angle fluctuation caused by the atmosphere turbulence. It was shown that the turbulence increases degree of the bit error at low elevation angles [Yamada, K. et al., 2002a, 2002b, 2003].
effect on the earth-space path was measured by the VSAT system using JSCAT-1B
Satellite link simulator is one of key tools to develop new protocol or improve existing one for high-data rate and efficient satellite communication systems. A bit error generation algorithm was proposed based on statistical characteristics of received signal level, and produced bit errors agreed well with experimental data [Franklin et al., 2004].
A. Street Microcell Systems
In order to characterize the propagation
phenomena in environments where the antenna height of base stations is lower
than that of the surrounding buildings, experimental and theoretical analyses
were conducted. Propagation measurements were made in metropolitan
B. Macrocell/Microcell Systems
Numerous efforts were devoted in order to
clarify the propagation mechanism and to develop propagation models for
macrocell and microcell mobile radio systems. NLOS and LOS propagations in
microwave frequencies were studied through energetic propagation campaign
assuming a base station antenna situated above the surrounding buildings.
Frequency characteristics for urban path loss in the microwave band were found
to observe 21Log(f), nearly the same as conventional characteristics in the UHF
band. It was made clear that when applying the behavior to the Sakagami model
developed for UHF band and employing mobile-station antenna-height compensation
of the Okumura-Hata model, estimated and measured values agreed well [Sakawa et al., 2002a, 2002b, 2002c, 2002d].
Nishi et al. presented the measured results of propagation
loss characteristics in UHF-TV band in various environments in
A new method for predicting the path loss in
over-rooftop propagation environments in microwave bands is proposed. In the
paper, it is clarified that the path loss due to distance can be divided into
three regions where the direct wave, the reflected wave, and the diffracted
wave are dominant, respectively. The validity of the model is tested by
measuring the path loss at 2.2 GHz and 5.2 GHz (CW) in suburban areas in
D. Indoor Propagation
Numerous experimental and
theoretical studies were done, particularly for WLAN and millimeter-wave
communications. A new method for measuring the quasi-instantaneous broadband frequency-domain
characteristics using an OFDM technique in 5.2-GHz band was introduced and the
results of the indoor measurements using the method were presented. A ray trace
simulation was also conducted for these rooms to evaluate the measured result [Kita
et al., 2002; Itokawa et al., 2002]. The results of an experimental study on
the propagation characteristics for broadband wireless access systems in
5.2-GHz band in an underground mall environment were presented by Itokawa et
al. It was made clear that the influence of the shadowing caused by passersby
can be reflected by an exponential term that includes the density of the
passersby. Also it was presented the maximum delay spread value during the rush
hours is at most 65 nsec [Itokawa et al., 2003]. Tachikawa et al. presented the
optimum tilt and beam width of the terminal antenna for indoor high data-rate
wireless communications for establishing a link between terminals by
considering the situation in which a partition was placed in the middle of an office,
and showed the angle of arrival characteristics of multipath waves. It is revealed that the optimum tilt
angle with the HPBW (Half Power Band Width) of 30 degrees is 50 to 60 degrees
when the data rate is greater than 10 Mbps in the considered situation
[Tachikawa et al., 2001]. The penetration from outdoor to indoor is also of
interest. Miura et al. carried out the outdoor-to-indoor propagation loss
measurements at 8 GHz and proposed a new propagation model to accurately
predict penetration loss [Miura et al., 2002]. On the millimeter-wave
communications, experimental results of indoor propagation characteristics in
60GHz, in Japanese style wooden houses, are described. The values of
wall-attenuation and an estimation method of the received signal level, and the
delay spread in indoor circumstances are discussed [Yoshikawa et al., 2001]. A
series of the studies on millimeter-wave wireless adhoc systems were reported
since 2002. A strict equation for the Fresnel zone radius was introduced. The
applicability of light emission method is presented by the difference angle
between light axis and LOS condition without shadowing the first Fresnel zone
[Hirose et al., 2002]. A detailed investigation of the propagation loss
characteristics along the surface of wooden and metal desk plane at 60 GHz was
described. The study assumes a two-ray propagation model, and shows a strong
match between the theoretical model and the measured data [Kuribayashi et al.,
2002]. RMS delay profile was measured in a wooden house and an office
environment in the millimeter-wave band and the measured results were reported
[Suzuki, T. et al., 2002]. A detailed investigation of the receiving power time
variation characteristics in 70GHz band indoor propagation was described
[Kuribayashi et al., 2003]. A propagation experiment was carried out in an
exhibition hall and the statistical characteristics of shadowing loss in 70GHZ
band was presented [Ohkubo et al., 2003a]. A conventional cafeteria in
E. Spatio-Temporal Channel Modeling and Measurement Method
The importance of the spatio-temporal propagation study has become great as the bandwidth of the wireless systems has become broad. A spatio-temporal channel characterization of a suburban non line-of-sight microcellular environment was studied. In the study azimuth-delay profiles obtained by the experiment are compared with ray-tracing simulation. The results are statistically treated in step by step to extract model parameters in order to characterize the spatio-temporal channel [Takada et al., 2002]. Oda and Taga proposed a clustering mechanism of multipath components in urban environments. Vector channel measurements at 5 GHz in an urban area verified the proposed clustering mechanism [Oda and Taga, 2002]. Ichitsubo et al. proposed a multipath propagation model for microcells in urban areas. The proposed model is a statistical geometric model that explains the propagation characteristics for propagation loss, the power delay profiles, and power azimuth spectra [Ichitsubo et al., 2002]. Imai and Taga proposed a stochastic scatter model in an urban area. The main feature of the model is that an ellipse expresses the effective scattering area. The major axis of the ellipse runs parallel along the street in which the mobile station is located [Imai and Taga, 2003]. Kitao and Ichitsubo proposed an angle profile model observed at base station in urban areas. Angle profile model was investigated to clarify the stochastic characteristics of the difference between the received levels of the sector antenna in order to control handover appropriately [Kitao and Ichitsubo, 2004a]. Okamoto proposed a model of arrival wave distribution for evaluating adaptive array antenna at mobile station. The 3-dimensional measurements were carried out in suburban area to confirm the proposed model [Okamoto, H., 2004]. A time-space path model especially suitable for position determination was proposed. The model explains well actual propagation environments [Omote and Fujii, 2002a]. Omote and Fujii also proposed a new time-space path model, which was an extension of the previous model, taking the arrangement of buildings in the city part into account. And it was also shown that the analysis using the proposed model agrees well with the field measurement results [Omote and Fujii, 2002b and 2003a]. The precision of proposed methods by using the time-space path model was estimated quantitatively [Omote and Fujii, 2003b]. Mathematical foundation of the time-space path model was established through theoretical analyses [Fujii and Omote, 2004; Fujii, 2004].
F. MIMO Channel Modeling and Measurement Method
Effect of multipath fading and its countermeasure for radio communication systems have been of interest for a long time. In recent years, using adaptive array antennas both at the base station (or access point) and user terminal, MIMO (Multiple-Input Multiple-Output) has been popular research field of next-generation mobile communication systems. The increase of system capacity without increasing the transmission power or frequency bandwidth has made the MIMO system unique and efficient in data transmission. Karasawa dealt with MIMO propagation channel modeling which might be one of the important study areas realizing effective MIMO communication systems having higher channel capacities. After tutorial description of a propagation channel model for Rayleigh fading, two recent propagation-related topics on MIMO system, i) MIMO utilizing dual and triple polarization diversity branches and ii) Tx/Rx weight mismatch problem for open-loop control system such as eigen-beamforming data transmission system, are highlighted [Karasawa, 2004; Das et al., 2004a and 2004b]. Based on indoor radio channel measurements, it was shown that the performance of MIMO-SDM in line-of-sight environments is better than that in nonline-of-sight environments. It was also shown that the performance of line-of-sight environments tends to change largely depending on the configuration of antennas [Nishimoto et al., 2004a, 2004b]. The suitability of a complex MIMO channel matrix for spatial multiplexing was verified experimentally in 5.2-GHz band in terms of the Demmel condition number. The instantaneous 2 x 2 MIMO-OFDM channel measurements in several indoor environments indicate the location dependency of the condition number. Wideband frequency characteristics were also analyzed to evaluate the applicability of spatial multiplexing [Kita et al., 2004a, 2004b]. Tachikawa et al. investigated the frequency correlation characteristics of the channel capacity for broadband MIMO channels in NLOS indoor environments. In the paper, the dependency of the element spacing on the frequency correlation characteristics was particularly focused. The calculation results agree well with the measured results in NLOS indoor environments [Tachikawa et al., 2004]. Simulation and experimental evaluation results of a circular and linear polarized antenna array applied to the MIMO system in an indoor environment were presented. A ray-trace simulation is used for the theoretical analysis. Measurements are carried out using a newly developed 2x2 MIMO-OFDM channel measurement system. The analysis results in terms of OFDM sub-carriers were also presented [Yamada, W. et al., 2004a]. Yamada et al. also presented frequency correlation of a MIMO-OFDM channel matrix in a real indoor environment. The eigenvector correlation of the wideband MIMO-OFDM channel matrix obtained from an actual indoor environment was used as an evaluation parameter of the frequency correlation characteristic. The knowledge of the frequency correlation of a MIMO-OFDM channel enables to reduce the calculation of MIMO channel matrix for each OFDM sub-carrier [Yamada, W. et al., 2004b].
G. Ultra Wideband
UWB is also one of the latest interests in the propagation field. Kobayashi and Kouya summarized the features of ultra wideband technologies, their origins, and the recent progress of the research and development, including UWB propagation studies [Kobayashi and Kouya, 2003; Kobayashi, 2003]. Sato and Kobayashi proposed a new UWB line-of-sight path loss formula based on the narrowband two-path (direct and ground reflected waves) model, taking into account the bandwidth of signals. Indoor experimental results verified the validity of this new formula [Sato and Kobayashi, 2004]. Short-range propagation measurements were carried out using UWB (3.1 to 10.6 GHz) and continuous wave (CW) signals on a rectangular metal plate simulating typical desks with and without a low vertical metal partition panels. With the partition panel, the CW reception level showed approximately a 36-dB spatial variation, induced by the interference between the direct and the reflected waves, but the UWB reception level had no particular plunges. They also measured the additional losses when the propagation paths were blocked with a human arm and when the antenna was covered with a human palm [Suzuki and Kobayashi, 2003]. Results of experiments in an anechoic chamber that assessed the reliability of UWB channel sounding system based on a deterministic approach with SAGE algorithm was presented. The system could resolve and detect 10 [deg] separated waves in angle domain, which was near the resolution limit. In the delay domain, 0.67 [ns] separated waves could be resolved where the relation between the bandwidth of subband and spectrum estimation was discovered [Haneda et al., 2004a]. Spatio-temporal analyses of LOS and NLOS home environments based on the deterministic approach were presented. The paths estimated with a SAGE algorithm were classified into several clusters by a heuristic approach. The identified clusters were determined from the physical structures of the environments, i.e. room height, specular directions, and size of scatterers in both the LOS and NLOS environments. The results imply that the spatial and temporal channel characteristics are highly correlated [Haneda et al., 2004b]. Haneda et al. also presented the results from double directional channel measurements in a typical home environment with ultra wideband signal. 100 ray paths were extracted using the SAGE algorithm at the both sides of radio link and they are regarded as dominant propagation phenomena. Then the paths were identified to the real environment, in which clusterization analyses were examined [Haneda et al., 2004c, 2004d]. Another study on UWB propagations was by Suzuki and Kobayashi. The paper described the development and experimental verification of the UWB spatio-temporal channel sounding system with use of a UWB monopulse antenna [Suzuki and Kobayashi, 2004].
The research on
adaptive array processing, DOA (Direction of Arrival) estimation and their
implementations in beamformer circuits using FPGA (Field Programmable Gate
Array) have intensively been made at
Propagation research in millimeter-wave band was made particularly for ITS, Intelligent Transportation System, applications. Propagation loss characteristics for inter vehicle communication system was measured in NLOS condition at 60GHz [Yamamoto et al., 2002]. Millimeter-wave path loss between two cars was also measured by Takahashi et al. to obtain the general applicable distance for inter-vehicle communication systems in real environments [Takahashi, S. et al., 2003]. The path loss measurements were carried out using 60-GHz CW radiowaves with standard horn antennas on metropolitan highways and regular roads. Fading characteristics of 60GHz inter-vehicle communications were also studied [Kawakami et al., 2002]. Kawakami demonstrated the data transmission between the two running vehicles, and the cumulative distribution of received power and fade durations average level crossing rate were measured at the experiment. Transmission loss of windshield and effect of rain drop on windshield surface were measured in the 60 GHz band [Sato and Fujise, 2002]. The transmission loss by the windshield is around 2-5dB and the attenuation by rain drop on windshield is about 5 dB. A Radio-On-Fiber system using millimeter-wave transmission has great potential for future road-vehicle communication. However, very intense fading occurs in the interference region because the same frequency is used for different cells. The availability of diversity to solve this problem is discussed [Sato and Fujise, 2004].
Studies for the reception of mobile satellite systems were also made. A performance of a satellite tracking control system for mobile DBS reception was presented. In order to improve the tracking speed and the stability of this system, a directional sensor function is added to a conventional left-right tracking algorithm [Kim, D. et al., 2002].
Imai proposed a prediction method of propagation loss characteristics in tunnels using ray-tracing method. The prediction effectiveness and accuracy in ray-tracing method was discussed based on the comparison made between the results of ray-tracing and of the actual measurement [Imai, 2002].
F2 Remote Sensing
In this section, remote sensing of atmosphere from the ground to the altitude of about 100 km is reviewed.
GPS (Global Positioning System) meteorology is a sounding technique of the atmosphere, by measuring propagation delay time of radio waves transmitted by GPS satellites. It provides us with information of electron density in the ionosphere, temperature in the stratosphere and humidity (water vapor) in the troposphere. The receiver could be located either on the ground or on board of LEO (low earth orbit) satellite. Experiments with receivers at the top of the mountain or on board aircrafts are also on going (down-looking GPS measurement).
The LEO measurement with CHAMP and SAC-C satellites revealed structure and atmospheric waves such as Kelvin waves and gravity waves in the troposphere and stratosphere [Tsai et al., 2004; de la Torre et al., 2004; Tsuda and Hocke, 2004; Ratnam et al., 2004]. Ground based GPS receiver network measurements has been applied to derive tri-dimensional structure of the water vapor in the troposphere [Noguchi et al., 2004]. The down-looking GPS measurement for tropospheric water vapor measurements are being developed by both analysis technique [Mousa and Tsuda, 2004], and experiment [Aoyama et al., 2004].
B. Various Techniques of Observation in Atmosphere with MST (Mesosphere Stratosphere Troposphere ) and Other Radars
It is common for the ST/MST radars to use bi-phase pulse-code compression in order to obtain a better signal to noise ratio and obtain a better height and time resolution as well as height coverage. New pulse compression codes which show better suppression of the radio interference has been proposed and used in the MU (middle and upper atmosphere) radar [Ghebrebrhan et al., 2004]. Structure-function analysis has been applied to the MU radar spaced antenna observation in the troposphere and variances of horizontal turbulent velocity components and horizontal momentum flux [Praskovsky et al., 2004]. The many beam method has clarified detailed horizontal structure of the tropospheric scatterer [Hirono et al., 2004].
radar (wind profiler) for lower tropospheric observations (Lower Troposphere
Radar: LTR), as an extension of the 1357.5-MHz boundary layer radar (BLR) has
been developed. System gain of this radar is improved due to newly developed
large-sized active phased-array antenna, active transmitting modules with
higher output power, and pulse compression technique (an antenna gain of 33 dBi
with a 4 m x 4 m active phased array antenna, and a peak output power of 2 kW)
[Hashiguchi et al., 2004]. This radar has been applied to various interesting
and important weather disturbances such as tropical typhoon [Teshiba et al.,
2004a] and orographic rain band in Baiu season [Umemoto et al., 2004]. It
should also be noted that this radar has now been distributed over
A 35 GHz radar to observe smaller particles such a as clouds and fogs has been developed and applied to the observation of fog, which was difficult to detect by radars before [Hamazu et al., 2003; Teshiba et al., 2004b].
A low elevation sidelobe suppression algorithm based on the uniform physical theory of diffraction (PTD) is developed to simulate ground clutter prevention fences for boundary layer radars [Rao et al., 2004]. Calibration method of the interferometers in meteor radars has been developed by a statistical approach [Holdsworth et al., 2004].
C. Mesosphere and Lower Thermosphere (MLT) Region
Mesosphere and lower thermosphere region exhibits special interests because it is a transient region between the neutral and ionized atmospheres, and eddy diffusive and molecular diffusive atmospheres. Variability of this region has been studied intensively by using observations, modelings and theoretical works.
As for the observational study, combined radio and optical techniques has contributed significantly. The wind observation using meteor echoes with the MU radar is the most sensitive meteor radar observation in the world and has revealed horizontal structure of the wind field in the MLT region and clarified its effect on the airglow imaging and wave breaking [Nakamura, T., et al., 2002]. Ejiri et al. used two airglow imagers near the MU radar site and measured the height of small-scale ripple structure in the airglow for the first time. In the rocket campaign of airglow structure in the MLT region (WAVE 2000 campaign), observations by ground-based airglow imaging observations as well as the MU and an MF radar wind observation has revealed the tri-dimensional structure of the airglow [Iwagami et al., 2002]. The local-time height variation of the airglow layer has now been understood as one of the reason of the difference of radar derived and optically derived wind velocity, which has been an issue discussed for a long time [Fujii, J., et al., 2004]. Temperature obtained by O2 airglow at around 90 km has been used to discuss the atmospheric density variation by a combined observation with the MU radar [Takahashi, H., et al. 2004].
D. Equatorial Atmosphere Radar (EAR) and CPEA (Coupling Processes in the Equatorial Atmosphere)
The Equatorial Atmosphere Radar is a VHF atmosphere radar at 47 MHz with 100kW output equipped with an active phased array antenna. It is located at Kototabang, West Sumatra (100.3 deg E, 0.2 deg S) and started observation in 2001 [Fukao et al., 2003], and has been very successfully used for the study of equatorial atmosphere dynamics, which is very important study in order to understand the drive source of the whole global atmosphere as well as the environmental change of the earth's atmosphere. A project for studying the coupling processes in the equatorial atmosphere using the EAR and related instruments developed and installed in Indonesia has started as a six year project in 2001, which is on-going now (CPEA: Coupling Processes in the Equatorial Atmosphere).
The tropopause variations due to breaking of Kelvin waves and associated turbulences have been observed in detail with the EAR [Fujiwara, M., et al., 2002]. A tilted echo layer and Kelvin-Helmholtz instability around the equatorial tropopause have been investigated by the EAR observations [Yamamoto, M.K., et al., 2003]. Intraseasonal oscillation in the zonal wind with periods of 20 - 50 days in the mesosphere and its association with the tropical convection and tides have been clarified by a long term meteor and MF radar observation in the equatorial region [Isoda et al., 2004]. Atmospheric wave generation and its propagation have been studied in the DAWEX (Darwin Area Wave Experiment) campaign [Tsuda et al., 2004].
F2.2 Hydrometeors and Other Particles
In this section,
recent research activities in
A. Ground-based Remote Sensing Studies
To study the vertical structure of tropical rainfall, the melting layer model and the vertical drop size distribution (DSD) model both used for TRMM PR algorithm were compared with the zenith-pointing Doppler rain radar observation. It was shown that there existed the agreement between the model and the observation in stratiform rain. However, vertical structure of convective rains is more variable and cannot be explained in the current DSD model [Thurai et al., 2003b].
millimeter-wave radar observations of wintertime thunderstorms are compared with
the C-band radar observations at Mikuni,
B. Space-based Remote Sensing Studies
The Precipitation Radar (PR) of the Tropical Rainfall Measuring Mission (TRMM) and its six-year observation results are summarized [Okamoto, K., 2003, 2004; Okamoto, K., et al., 2004]. The averaged heights of the bright-band are calculated by using 4 year TRMM PR data [Thurai et al. 2003a]. Results of external calibration of the TRMM PR are summarized [Takahashi, N. et al., 2003]. A surface elevation map is generated using the PR data, for the purpose of improving the rejection of ground clutter in the rain observation by a radar from space [Awaka and Takahashi, 2004]. Studies to improve the PR retrieval algorithms were made [Thurai et al, 2003b], [Meneghini et al., 2004]. Correction of the PR beam mismatch after an orbit change was reported [Takahashi and Iguchi, 2004]. Studies on the precipitation radar to be boarded in the Global Precipitation Mission (GPM) have also been made [Kobayashi and Iguchi, 2003; Mardiana et al., 2004a, 2004b].
Multiple scattering properties of random particles at 30 GHz band at the scattering angles in the vicinity of zero degree were investigated in a controlled laboratory measurement using a mirror image technique [Ihara et al., 2004a]. The measurement gave quantitative results on the backscattering enhancement due to random particles in the millimeter-wave band. The scattering angle dependence of scattered power showed its clear peak in the close vicinity of backward scattering direction for both VV and VH polarizations.
F2.3 Ocean and Ice
Methods for measuring characteristics of ocean waves using satellite altimetry were studied, and it was shown, by a simulation study, that there existed a relation between the significant ocean wavelength and pulse-to-pulse correlation coefficient [Fujisaki et al., 2001, 2003].
A technique to detect ships using synthetic aperture radar (SAR) data was studied [Ouchi et al., 2004]. The technique detects ships from the coherence images produced by cross-correlating multilook images of sea surface. Using this processing algorithm, ships that are not clearly visible in radar images can be detected. The principal theory and experimental results using the JERS-1 L-band and RADARSAT-1 C-band SAR data are reported. Analysis of SAR images of ships in pitching motion was also reported [Ouchi et al., 2002a]. It is shown theoretically and experimentally, on the SAR images, that when ships are in pitching motion the image of the hull is not aligned with the direction of propagation, but displaced in a non-linear manner facing different directions.
Method for deriving of sea ice thickness from
SAR image data is one of the major topics in remote sensing of ice. As an attempt to develop an algorithm
for deriving the sea ice thickness from SAR data, thickness of a salinity lake
was examined and successfully retrieved from the multi-incidence angle data of
the RADRASAT [Nakamura et al., 2002]. The results showed very good
correspondences in the whole lake to the bore-hole measurements.
More parametrical study for the sea ice thickness was carried out by using
dual-bands (X and L) polarimetric airborne SAR (Pi-SAR) [Matsuoka, T. et al.,
2002; Wakabayashi et al., 2004]. The study resulted in the finding of an
algorithm which can infer the ice thickness using the VV and HH ratio, being
applied to the real sea ice in the
Semi-automatic detection method of sea ice
motion, using the RADARSAT-1 satellite SAR images observed at two-day interval,
was proposed [Enomoto, et al., 2003]. Motion detection algorithm was commonly
proposed for the arctic sea ice, but the algorithm is not applicable to
detection of the ice movement in the
F2.4 Land, Vegetation, Subsurface Objects, Landmine and Others
A. Land and Vegetation
Fully polarimetric synthetic aperture radar (SAR) sensing has been attracting attention from theory to data analysis, in various areas including land, vegetation, and others.
Polarimetric indices for extracting scattering characteristics of trees were investigated to show that the correlation coefficient in the circular polarization basis best serves to classify conifer trees and broad leaf trees [Murase et al., 2001]. Characteristic polarization states of a scattering object via equi-power curves on the Poincare sphere were derived, and the property of scattering matrix was examined mathematically to derive the periodicity of scattering matrix nature that is applied to classify the targets [Yang et al., 2002a, 2002b]. The image simulations of the spaceborne ALOS-PALSAR to be equipped with fully polarimetric data take function were carried out using airborne Pi-SAR polarimetric data taking into account of radar resolutions, and comparison was made between image data acquired with AIRSAR (JPL) and that with Pi-SAR (CRL/NASDA) during the Pacific-Rim flight campaign [Yamaguchi et al., 2002a, 2002b]. Polarimetric filtering technique to detect objects buried in the underground, using null state to eliminate the surface clutter was also presented [Yamaguchi et al., 2002c]. Generalized optimization (generalized eigenvalue problem) of polarimetric contrast enhancement method was developed to find specific target over the clutter in fully polarimetric SAR image [Yang et al., 2004]. It was attempted to classify terrain target using polarimetric entropy, alpha angle, and total power [Kimura et al., 2004a]. Based on unsupervised maximum likelihood method, it is shown that the method is effective for classification in complex environment. It is shown that the phase of the correlation coefficient in the circular polarization basis is effective for detection of man-made targets such as buildings and building blocks not parallel to SAR flight path [Kimura et al., 2004b]. The correlation coefficients in the various polarization bases were examined and it was shown that the phase in the circular polarization correlation coefficient is effective for feature extraction [Moriyama et al., 2004]. The analysis of SIR-C data was made using a target decomposition method and the scattering mechanisms and their dependence on radar parameters as well as the season of observation were characterized [Fujita and Nakamura, 2003]. Pi-SAR polarimetric data were used for classification of trees, based on the alpha-entropy methods, to discriminate conifer and broad leaf trees [Sato and Iribe, 2003], and for land use classification [Amarsaikhan and Sato, 2004]. It was found that the phase component of the circular polarization of the Pi-SAR data shows a unique behavior that may be closely related to the azimuth orientation of the radar target and can be used for quantitative classification [Iribe and Sato, 2004].
An alternative approach for polarimetric SAR interferometry based on the ESPRIT technique was proposed [Yamada, H. et al., 2002]. The approach has a feature to detect local scattering centers corresponding to the canopy top and the ground and can detect three local scattering centers in the forest at the maximum with fully polarimetric data sets. This feature is applied to improve the tree height estimation [Sato, K. et al., 2003]. It is also shown that strong volume scattering causes the bias in the estimated tree height, so that careful evaluation of the results is necessary for the dense forest analysis [Yamada, H. et al., 2003].
An X-band scatterometer was applied to monitor wheat chlorophyll, to show that polarimetric power ratio varies with wheat growing stage [Singh et al., 2003].
Algorithms of classifying rice paddies and
their applications to monitoring growth of rice plants are presented. The
algorithms were applied to the airborne Pi-SAR data over the Kojima test
SAR techniques were used for a ground-based (GB) system. A prototype of GB-SAR was tested and used for 3-D imaging of trees. Radar polarimetry was also applied for interpretation [Zhou et al., 2004]. GB-SAR was used for detection of small deformation of radar target by interferometry. Deformation of the order of 1cm of a wall of a wooden house was detected [Hamasaki et al., 2004].
Theoretical study of microwave sensing of soil moisture was carried out [Matsuoka and Tateiba, 2003]. In the study, a moist soil was assumed to be three layers of random medium and a radiative transfer theory was applied to evaluate the scattered power. The polarization ratio is useful for estimate of water contents near surface. Diurnal change of backscattering coefficients of Amazon rain forest at Ku-band was studied with the TRMM PR, to find larger backscattering in the morning [Satake and Hanado, 2004].
B. Subsurface Objects
Low frequency induction is used for deep geological exploration for oil and mineral resources. A novel directional induction logging sensor was proposed [Cheryauka and Sato, 2002]. Radar polarimetry was applied to a borehole radar in a deep drilled borehole and it was tested for evaluation of subsurface fractures [Sato and Takeshita, 2002]. The theoretical principle and numerical simulation of a polarimetric borehole radar for subsurface fracture characterization were demonstrated [Sato, 2004]. Sub-grid FDTD method was applied to the simulation of radar scattering of a borehole radar system [Liu et al., 2004]. Small migration of ground water level was determined quantitatively and the vertical profile of ground water content could be estimated by Ground Penetrating Radar (GPR) [Lu and Sato, 2002]. Lu and Sato  also demonstrated the quantitative GPR measurement can estimate the hydraulic parameters of soil, which will leads to the production estimation of grounds water.
C. Landmine Detection
A stepped-frequency radar with wide bandwidth (10MHz-6GHz) and thereby with very high resolution was developed for the use of landmine detection [Sato, M. et al., 2003]. Bistatic ground penetrating radar (GPR) system using a passive optical electric field sensor was also proposed for landmine detection [Sato, M., 2003]. Wide band GPR using an array Vivaldi antenna, that is called SAR-GPR with SAR imaging algorithm incorporated, was demonstrated to show a good performance for landmine detection [Sato, M. et al., 2004].
An earthquake detection system which uses satellites to receive microwaves was proposed [Takano et al., 2004]. The mechanism of the microwave generation in relation to an earthquake is explained on the basis of the experiment of rock-crash in a laboratory. The sensitivity of the satellite sensor and the coverage by a receiving antenna are discussed and clarified.
Microwave emission due to hypervelocity impacts on metallic plates has been found, in the experiment with aluminum plates of various thicknesses and the projectile made of a nylon cylinder with a metal. A heterodyne receiver detected the microwave, a random sequence of pulses with several nanosecond width, at 22 GHz. Since the phenomenon seems to be dependent on the extent of target destruction through the formation of impact craters or penetration, it could be used to better understand the mechanical destruction process [Takano, et al. 2002]. The dependence of emitted frequency (22 GHz and 2 GHz), the time sequence of the signal generation, the correlation with the light emission and the emitted energy was investigated [Maki et al. 2002]. The emission characteristics are studied for several kinds of targets of aluminum, an alumina ceramic, a red brick and a polyurethane rubber. The strength of the emission has correlation to the electric conductivity, the fragility and the density of the targets [Maki et al. 2003]. To understand the features of the phenomena and to clarify the mechanism of the radio-wave generation, the simultaneous observation of the phenomena by the micro-wave detection and the optical imaging method to compare the both methods was carried out [Maki et al., 2004].
The scattered patterns of light-wave from several materials have been measured. Acrylic plastic has Lambertian pattern due to strong internal scattering and a reflection pattern from the surface [Toyoshima, et al. 2004].
Akeyama, A., F. Ohkubo, M. Ida, A. Kanazawa and H. Ogawa , Millimeter-wave ad-hoc wireless access system -(5)propagation characteristics in indoor environments-, Proc. of 2003 IEEE TCWCT, Honolulu, Hawaii, 21-5.
Akimoto, M., K. Harada, and K. Watanabe [2003a], Long-term changes in rainfall tendency and estimation method of one-minute rain rate distribution in Japan, Proc. of IEEE Wireless Communications and Networking Conference 2003 (WCNC2003), New Orleans, USA, vol.1, pp. 162-166.
Akimoto, M., K. Harada, K. Watanabe, T. Ichikawa [2003b], Long-term changes in rainfall tendency and estimation method of one-minute rain rate distribution in Japan, Trans. IEICE Japan, vol. J86-B, no. 10, pp. 2166-2173. (in Japanese).
Amarsaikhan, D. and Sato, M., , Validation of the PiSAR data for land cover mapping, Journal of the Remote Sensing Society of Japan, Vol.24, no.2, 133-139.
Aoyama, Y., Y. Shoji, A. Mousa, T. Tsuda, and H. Nakamura ,
Temperature and Water Vapor Profiles Derived from Downward-Looking GPS
Occultation Data, J. Meteorol. Soc.
Arai, H. and M. Kim , Hardware design of RF and digital units for
smart antenna system, Proc. of
Asia-Pacific Microwave Conference,
Cheryauka, A. and Sato, M., , Directional Induction Logging for Evaluation of Layered Magnetic Formations, Geophysics, vol.67,no.2, 427-437.
Das, N. K., M. Shinozawa, N. Miyadai, T. Taniguchi and Y. Karasawa [2004a], An experiment on MIMO system having dual polarization diversity branches, Proc. of International Symposium on Antennas and Propagation (ISAP04), Sendai, Japan, vol.1, pp.341-344.
Das, N. K., T. Inoue, T. Taniguchi and Y. Karasawa [2004b], An experiment on MIMO System having three orthogonal polarization diversity branches in multipath-rich environment, Proc. of IEEE Vehicular Technology Conference 2004-Fall, LA, CA.
Davidson, G., K Ouchi, G Saito,
Davidson, G., and K.Ouchi , Segmentation of SAR images using multitemporal information, IEE Proc. Radar, Sonar and Navigation, vol.150, no.5, pp.367-374.
Ejiri, M. K., K. Shiokawa, T. Ogawa, M. Kubota, T. Nakamura, T. Tsuda , Dual-site imaging observations of small-scale wave structures through OH and OI nightglow emissions, Geophys. Res. Lett., vol. 29, no. 10, art.no.1445.
Enomoto, H., T. Kumano, N. Kimura, K. Tateyama, K. Shirasawa, and S. Uratsuka , Sea-ice motion in Okhotsk Sea derived by microwave sensors, Proc. 30th ISOP, Honolulu, 518-522.
Franklin, F. F, K. Fujisaki, T. Matsuoka, and M. Tateiba , A Satellite link-like bit errors model based on the received signal level for link simulator's noise implementation, Proc. of 2004 International Symposium on Antennas and Propagation (ISAP04), pp. 1373-1376, Sendai, Japan.
Fujii, J., T. Nakamura, T. Tsuda, and K. Shiokawa , Comparison of wind velocity between MU radar and FPI considering OI5577 airglow height variations, J. Atmos. solar-Terr. Phys., vol. 66, pp. 573-583.
Fujii, T. , Delay profile modeling for wideband mobile propagation, Proc. of IEEE Vehicular Technology Conference 2004-fall, Los Angels, CA.
Fujii, T. and H. Omote , Time-spatial path modeling for wideband mobile propagation, Proc. of IEEE Vehicular Technology Conference 2004-fall, Los Angels, CA.
Fujisaki, K., Y. Iwata, K. Ishida, and M. Tateiba , Experimental studies of airplane effects on satellite communications at Kyushu University, Proc. of 2002 Asia-Pacific Conference on Communications, Kyoto, Japan, pp.198-201.
K., H. Umeda, and M. Tateiba , Studies on Developing the Method for Measuring
Characteristics of Ocean Waves Using Satellite Altimetry, Proc. 2003 Asia-Pacific Microwave Conf.,
Fujita, M., and S. Nakamura , Target decomposition analysis of SIR-C imagery for characterization of scattering mechanisms and their dependence on observation parameters, IEEE Trans. Geosci. Remote Sensing, vol. 41, no. 12, pp. 2721-2724.
Fujita, S., H. Maeno, T. Furukawa, and K. Matsuoka, Scattering of VHF radio waves from within the top 700m of the Antarctic ice sheet and its relation to the depositional environment: a case-study along the Syowa-Mizuho-Dome Fuji traverse, Annals of Glaciology, 34,157-164.
Fujita, S., K. Matsuoka, H. Maeno, and T. Furukawa , Scattering of VHF radio waves from within an ice sheet containing the vertical-griddle-type ice fabric and anisotropic reflection boundaries, Annals of Glaciology, 37,305-316.
Fujiwara, M., M. K. Yamamoto, H. Hashiguchi, T. Horinouchi, and S. Fukao , Turbulence at the Tropopause due to Breaking Kelvin Waves Observed by the Equatorial Atmosphere Radar, Geophys. Res. Lett., vol.30, no.4, art no. 1171, doi:10.1029/2002GL016278.
Fujiwara T., Y. Maekawa, Y. Shibagaki, T. Sato, M. Yamamoto, H. Hashiguchi, and S. Fukao , Cumulative time percentages of rainfall rate of rain attenuation observed on the satellite links at equatorial atmospheric radar, Proc. of 2004 International Symposium on Antennas and Propagation (ISAP04), vol.2, pp.1357-1360, Sendai, Japan.
Fukao, S., H. Hashiguchi, M. Yamamoto, T. Tsuda, T. Nakamura, M. K. Yamamoto, T. Sato, M. Hagio, Y. Yabugaki , Equatorial atmosphere radar (EAR): System description and first results, Radio Sci., vol. 38, no. 3, 1053, doi:10.1029/2002RS002767.
Ghebrebrhan, O., H. Luce, M. Yamamoto, and S. Fukao , Interference suppression factor characteristics of complementary codes for ST/MST radar applications, Radio Sci., vol. 39, no. 3, RS3013, doi:10.1029/2003RS002901.
Hamasaki, T., Boerner, M., Sato, M. and Zhou, Z. , 3-D Broadband Ground-based Polarimetric SAR Data Processing for the Monitoring of Vegetation Growth Variations, IGARSS2004.
Hamazu, K., H. Hashiguchi, T. Wakayama, T. Matsuda, R. J. Doviak, and
Haneda, K., J. Takada and T. Kobayashi [2004a], Experimental evaluation of a SAGE algorithm for ultra wideband channel sounding in an anechoic chamber, Proc. of 2004 International Workshop on Ultra Wideband Systems Joint with Conference on Ultra Wideband Systems and Technologies, Kyoto, Japan., pp. 66-70.
Haneda, K., J. Takada and T. Kobayashi [2004b], Clusterization
analyses of spatio-temporal UWB radio Channels in line-of-sight and non-line-of-sight
indoor home environments, Joint COST
273/284 Workshop on Antennas and Related System Aspects in Wireless
Haneda, K., J. Takada and T. Kobayashi [2004c], Double directional
LOS channel characterization in a home environment with ultra wideband signal, Proc. of The Seventh International Symposium
on Wireless Personal Multimedia Communications (WPMC2004),
Haneda, K., J. Takada and T. Kobayashi [2004d], Double directional ultra wideband channel characterization in a line-of-sight home environment, COST 273 11th Management Committee Meeting, Duisburg, Germany.
Hasanuddin, B. Z., K. Fujisaki, K. Ishida, and Mitsuo Tateiba [2002a], Worst Month And Yearly Distribution of Ku-Band Rain Attenuation at Three Different Locations in Kyushu, Japan Proc. of 2002 Asia-Pacific Conference on Communications, pp. 194-197.
Hasanuddin, B. Z., K. Fujisaki, K. Ishida, and M. Tateiba [2002b], Measurement of Ku-band rain attenuation using several VSATs in Kyushu island, Japan, IEEE Antennas and Wireless Propagation Letter, Vol.1, No.5, pp. 116-119.
Hasanuddin, B. Z., K. Fujisaki, K. Ishida, and M. Tateiba , Relation of worst month and yearly distributions of Ku-band rain attenuation in Kyushu Island, Japan, IEE Electronics Letters, Vol.39, No.3, pp.320-321.
Hashiguchi, H., S. Fukao Y. Moritani, T. Wakayama, and S. Watanabe , A lower troposphere radar: 1.3-GHz active phased-array type wind profiler with RASS, J. Meteor. Soc. Japan, vol. 82, no. 3, pp.915-931.
Hayashi, T., K. Ichige and H.Arai , Accurate DOA estimation using modified fast EM algorithm, Proc. of Asia-Pacific Microwave Conference, Seoul, Korea, pp. 1644-1647.
Hirono, M., H. Luce, R. M. Worthington, M. Yamamoto, and S. Fukao , Horizontal maps of echo power in the lower stratosphere using the MU radar, Ann. Geophys., vol.22, no.3, pp. 717-724.
Hirose, H., K. Sakamoto, T. Hiratsuka, A. Akeyama, K. Hamaguchi, Y. Shoji and H. Ogawa , Millimeter-wave ad hoc wireless access system -(7)strict solution of Fresnel zone radius and indoor visibility estimation-, Proc. of TSMMW2002, Yokosuka, Japan, P-7.
Hirota, A., K. Ichige and H. Arai , DOA estimation by eTf-type
array antenna and its evaluation, Proc.
of URSI General Assembly,
Hirota, A., K. Ichige, H.Arai, K.Min, D.Kim, J.Kim and M.Nakano , A DOA estimation system in 900 MHz by eTf-type array antenna, Trans. IEICE Japan, vol. J86-B no. 10, pp. 2153-2165.
Hirota, A., H. Arai and M. Nakano , DOA estimation system by a
synthesized virtual planar array using pilot signals, Proc. of 2004 International Symposium on Antennas and Propagation
Holdsworth, D. A., M. Tsutsumi, I. M. Reid, T. Nakamura, and T. Tsuda , Interferometric meteor radar phase calibration using meteor echoes, Radio Sci., vol. 39, no. 5, Art. No. RS5012.
Ichige, K., M. Shinagawa and H. Arai , An algebraic approach to
eigenproblems toward fast DOA estimation, Proc.
of URSI General Assembly,
Ichige, K., M. Shinagawa and H. Arai , A fast algebraic approach to the eigenproblems of correlation matrices in DOA estimation, Trans. IEICE Japan, vol. E86-B, no. 2, pp. 865-869.
Ichitsubo, S., K. Tsunekawa and Y. Ebine , Multipath propagation model of spatio-temporal dispersion observed at base station in urban areas, IEEE Journal on Selected Areas in Communications, vol. 20, Issue 6, pp.1204–1210.
Ihara, T., Tomohiro Oguchi, and Tamio Tazaki [2004a], Measurement of backscattering enhancement due to random particles at 30 GHz band using mirror image technique, URSI Commission F Triennium Open Symposium, Cairns, Australia, pp.59-64.
Ihara, T., T. Oguchi and T. Tazaki [2004b], Complex refractive index of soda-lime glass: measurement at 30-GHz and empirical formula in microwave and millimeter-wave regions, IEICE Trans Commun., Vol.E87-B, No.10, pp.3155-3157 .
Imai, T. , Prediction of propagation characteristics in tunnels using ray-tracing method, IEICE Trans. Commun., vol. J85-B, no. 2, pp.216-226 (in Japanese).
Imai, T. and T. Taga , Stochastic model of scattering component distribution in outdoor propagation environment, Proc. of 58th Vehicular Technology Conference 2003-Fall, Orlando, USA, vol. 1, pp.104-108.
Inoue, Y., K. Mori H. Arai , DOA estimation in consideration of
the array element pattern, IEEE Proc.
of Vehicular Technology Conference
Inoue, Y., K. Shimizu, H. Arai, K. Komiya and K. Tsunekawa , Signal discrimination method based on the estimation of signal correlation using an array antenna, Proc. of IEEE Vehicular Technology Conference, Genoa, Italy.
Iribe, K. and Sato, M., , Incident angle dependence of Pi-SAR polarimetric scattering characteristics, Proc. ISAP2004, Sendai, Japan, 1289-1292.
Ishida.M, O.Sasaki, T.Taga and S.Ichitsubo , A study on rain fade duration
distribution characteristics on millimeter wave radio link, Proc. of ClimDiff 2003, Clim.52,
Ishida.M, O.Sasaki, M.Yoshikawa, A.Akeyama, N.Takahashi, K.Takanashi, A.Kanazawa and H.Ogawa , Development of Gigabit millimeter-wave broadband wireless access system (U)|(4) Estimation for probability distribution of rain attenuation at 32GHz band|, Proc. of Technical digest of the 6th Topical Symposium on Millimeter Waves (TSMMW2004).
Ishitsuka, N., G.Saito, K.Ouchi and S.Uratsuka , Observation of Japanese rice paddy fields using multi wavelength and full polarimetric SAR Remote sensing sensor on next generation satellite, Advances in the AstronomicalSciences, vol.117, pp.565-575.
Isoda F., T. Tsuda, T. Nakamura, R.A.Vincent, I.M.Reid,
Ito, C., and Y. Hosoya , A worldwide rain
attenuation prediction method which uses simplified Moupfouma distribution and
regional climatic parameters, Proc. of 2002 Interim International Symposium on
Antennas and Propagation (ISAP i-02), pp.295-298, Yokosuka, Japan.
Ito, C., and Y. Hosoya [2004a], A proposal of global rain attenuation
prediction method by using M distribution and regional climatic parameters, IEICE Trans. Commun., vol.
J82-B, 7, pp.979-989 (in Japanese).
Ito, C., and Y. Hosoya [2004b], An Investigation
on Lavergnat-Gole Conversion Method for Different Integration Time Rain Rate
Distributions by Using Regional Climatic Parameters, Proc. of 2004 International Symposium of Antennas and Propagation (ISAP04), pp.1361-1364, Sendai, Japan.
Itokawa, K., N. Kita, A. Sato and D. Mori , Experimental study of wideband propagation characteristics in an underground street at 5GHz band, Proc. of 2002 Interim International Symposium on Antennas and Propagation (ISAP i-02), pp. 408-411, Yokosuka, Japan.
Iwagami, N., T. Shibaki, T. Suzuki, Y. Yamada, H. Ohnishi, Y. Takahashi, H. Yamamoto, H. Sekiguchi, K. Mori, Y. Sano, M. Kubota, Y. Murayama, M. Ishii, K.-I. Oyama, R. Yoshimura, M. Shimoyama, Y. Koizumi, K. Shiokawa, N. Takegawa, and T. Nakamura , The WAVE 2000 campaign: Overview and preliminary results, J. Atmos. Sol.-Terr. Phys., vol. 64, no.8-11, pp. 1095-1104.
Iwai, H., K. Yonezawa, T. Maeyama, H. Shinonaga, H. Harada and M. Fujise , Path loss measurement in 5GHz macro-cellular environments, Proc. of The Six-th International Symposium on Wireless Personal Multimedia Communications (WPMC2003), MA8-4, Yokosuka, Japan.
Jinguu, S., H.
Kanazawa, A., H. Ogawa, K. Sakamoto, S. Tago, F. Ohkubo, M. Ida, A. Akeyama, N. Kuribayashi and T. Hirose , Measurement of complex permittivity of construction materials at 62GHz and 70GHz, IEICE Trans. B, J87-B, 3, pp.462-466.
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Kim, D., K. Min, and H. Arai , Performance of a satellite tracking antenna control system for mobile DBS reception, IEEK, vol. TC39, no. 4, pp. 52-60.
Kim, M., K. Ichige and H. Arai , FPGA-based DSP implementation of simple MRC beamformer, Asia-Pacific Microwave Conference, Taipei, Taiwan, R.O.C., vol. 2, pp. 589-592.
Kim, M., K. Ichige and H. Arai , Design of Jacobi EVD processor based on CORDIC for DOA estimation with MUSIC algorithm, Proc. of IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC2002), Lisbon, Portugal, No. MPO1.5.5.
Kim, M., K. Ichige and H. Arai [2003a], Implementation of FPGA based
fast DOA estimator using unitary MUSIC algorithm, Proc. of IEEE Vehicular Technology Conference,
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Matsuoka, T., and M. Tateiba , Analysis of wave scattering from three layers of random medium by using a radiative transfer equation, IEEJ Trans. FM., Vol. 123, No. 12, pp. 1193-1198. (in Japanese)
Matsuzaki, E., K. Ichige and H. Arai , An automatic recognition
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