Utility of proposed sensors for coastal engineering studies

The needs of coastal engineering are different from open ocean monitoring or fisheries potential monitoring. A high resolution of 20 meters is essential for identifying several processes that are taking place and influences the coast. A case of application of Landsat MSS to evaluate littoral process highlights the needs for improved spatial resolution. Nevertheless Landsat MSS data for 1981 and 1982 showed that the extent of accretion and erosion that has taken place during this period. Some problems to be addressed for marine remote sensing are mainly regarding the need for insitu data. These aspects are mentioned.     

Implication of multiple dipolarization event near 9 RE for the physics of substorms

In 2001, 2002 and 2003, the Polar spacecraft probed the near equatorial plasma sheet at 9 R_E near local midnight. Using the magnetic field observations, the signatures at substorm onsets are studied. Close to the flux pile-up region, the Polar spacecraft readily detects the dipolarization front, especially for pseudo onsets. An event with two distinct onsets has been examined. The signatures are found to be consistent with the multiple-onset model suggested by Russell [Russell, C.T. How northward turnings of the IMF can lead to substorm expansion onsets. Geophys. Res. Lett. 27, 3257–3259, 2000] which is a modified Near-Earth Neutral Line (NENL) model. Another similar event is also examined showing the effects of different Interplanetary Magnetic Field (IMF) conditions upon substorms. Moreover, ground effects can be very weak compared to in situ observations, especially for pseudo onsets, because these signatures appear to be localized and not global.     

Space weather center in Japan

Progress in information technology has enabled to collecting data in near real-time. This significantly improves our ability to monitor space weather conditions. We deliver information on near real-time space weather conditions via the internet. We have started two collaborations with space weather users. One is a measurement of geomagnetically induced current (GIC) of power grids in collaboration with a Japanese power company. The other concerns radiation hazards for aircrews. The radiation exposure level for aircrews was been determined by the Japanese government by the end of 2005. The proposed upper limit is 5 mSV a year. We are actively seeking ways to contribute to this subject. Our activities at the Japanese space weather center are reported in this paper.     

Influence of climatic operational conditions of a helicopter on physico-mechanical properties of composite materials

The results of numerical and experimental study of physico-mechanical properties of composite materials are proposed and variations in rigidity characteristics of the hub working part of the hingeless type within the entire range of helicopter operational temperatures are evaluated.     

Rejection of Multipath Interference in Satellite Communications by Use of Narrow-Band Filters

Earth-reflected multipath interference can be serious for communication between near-earth spacecraft and stationary satellites. It is shown that both the depth and rate of fading are reduced by using narrow-band filters. Curves demonstrate the saving in fading margin; this saving may be crucial in an emergency.     

Automatic Target Recognition: Some Considerations

Machine analysis of aerial reconnaissance data is desirable. New acquisition techniques, equipment, and sensors, plus a growing demand for rapidly obtained, accurate information necessitate machine performance of tasks presently accomplished by observers and interpreters. Many of these tasks can be described as pattern recognition or information processing functions. This paper discusses significant problems encountered when attempting to identify objects or regions automatically from aerial photography. Problems include sensor distortions, variations in target environment, and concepts of design and ?teaching? of an actual device. Operational requirements such as processing speed and flexibility restrict the types of solutions available. Approaches to target recognition with relative merits and shortcomings are presented; these include shape correlation, feature extraction, and image quantization. The effect of mission requirements on system parameters is discussed. A bibliography is included.     

An Automatic Data Processing System for Laser Anemometers

An automatic data processing system for the evaluation of statistically occurring Doppler-difference bursts is described. In addition to the higher accuracy compared with the data acquisition procedures known so far, this technique allows the Doppler-difference method to be used as an operational instrument for investigations into turbulent flows, especially in the case of low particle density and extremely small turbulence degrees.     

Studies of Logarithmic Radar Receiver Using Pulse-Length Discrimination

Using a logarithmic amplifier giving a detected output followed by a high-pass filter is a technique for reducing adverse effects of distributed clutter in radar receivers. A pulse-length discriminator (PLD) used as the high-pass filter is treated here. Theoretical and experimental results for the loss in detectability introduced by this receiver, as compared with a matched filter or a good approximation thereto, have been obtained. For the case of single-hit detection, losses of 4 to 8 dB are introduced by the logarithmic amplifier/pulse-length discriminator (LOG AMP/PLD) combination; for post-detection integration, the losses are reduced to 2 to 4 dB. The latter values would apply where the LOG AMP/PLD output is presented on a PPI (plan position indicator). Some experimental results of the ability of the LOG AMP/PLD receiver to reject signals of incorrect pulse length show that signals exceeding the design pulse length by more than 25 to 50 percent are effectively suppressed. No significant short-pulse discrimination is obtained from the receiver.     

The RadioAstron project: Measurements and analysis of basic parameters of space telescope in flight in 2011–2013

The results of a large number of the antenna radiometric measurements at bands of 92, 18, 6.2, 1.35, and 1.7-1.2 cm are presented by the data of the standard telemetry system of the Spektr-R spacecraft. Both special sessions of calibration object observations in the mode of a single space radio telescope (SRT) operation and numerous observations of researched sources in the mode of the ground-space interferometer were used. The obtained results agree with the first results of Kardashev et al. (2013), i.e., within 10–15% at bands of 92, 18, and 6.2 cm and 20–25% at the band of 1.35 cm. In the main, the measurements for the eight subbands at wavelengths of 1.7-1.2 cm indicate a monotonic increase in the spectral system equivalent flux density (SEFD) of noise radiation with a frequency consistent with the calculated estimates for the discussed model. The sensitivity of the ground-space interferometer for the five subbands at wavelengths from 1.35 to 1.7 cm can be higher by a factor of 1.5, and for the three subbands from 1.35 to 1.2 cm lower by a factor of 1.5 than at the band of 1.35 cm. The SRT contribution to the interferometer sensitivity proportional to the square root of SEFD is close to the design one at the bands of 92 and 18 cm and decreases the design sensitivity approximately by a factor of 1.5 and 2 at the bands of 6.2 and 1.35 cm, respectively. These differences of implemented values from the design ones were not significantly affected the scientific program implementation.     

Oxygen line mapping of SN 1006 with Suzaku

SN 1006 is one of the supernova remnants (SNRs) with relatively low-temperature electrons, considering the young age of just 1000 years. We carried out SN 1006 mapping observations with the X-ray Imaging Spectrometers (XIS) and the Hard X-ray Detector (HXD) onboard Suzaku, the fifth Japanese X-ray satellite. Thanks to the excellent spectral resolution of XIS in the soft X-ray band, H-like and He-like oxygen emission lines were clearly detected, and we could make a map of the line intensity, and as well as a flux and the photon index of nonthermal component. We found that these parameters have spatial dependences from region to region in the SNR; the north region is bright in nonthermal, while dim in thermal; the east region is bright in both nonthermal and thermal; the inner region shows dim nonthermal and bright thermal emission. The photon index is the smallest in the north region.