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[en] The Mikro-Kopter is the ultimate tool for aerial photography or security missions for short distances, times and low payloads. An experimental study of indoor and outdoor dispersion of radioactive material was conducted as a part of 'Green Field' and 'Red House' projects. The Mikro-Kopter used enables 20 min flights. The large arms angle allows wide angle photography and 300 gr of payload. It has a stabilizing system which together with a GPS it can keep the location at a certain height, and automatically return to the take-off point. Using a computer interface it can communicate with the ground system at real time, sending it to predetermined landmarks (or enter them in real time). After the flight it returns automatically to the take-off point. The Mikro-kopter's six powerful electric engines give the ability to simultaneously lift weight and keep high maneuverability. The ground station includes all the functions needed to fly the Mikro-kopter and controlling the payload on it. No eye contact is needed but it will help for durability in hard missions
[en] Complete text of publication follows. The development of equatorial ionospheric irregularities into large-scale ionospheric plasma bubbles continues to be an active area for scientific investigations. In this paper we present simultaneous OI 630.0 nm emission all-sky imaging observations carried out at the Astrophysics National Laboratory - 'LNA', Brazopolis (22.5deg S, 45.6deg W, altitude 1860 m) and ionospheric sounding observations carried out at Palmas (10.2deg S, 48.2deg W; located close to the magnetic equator) and Sao Jose dos Campos (23.2deg S, 45.9deg W; located under the southern crest of equatorial ionospheric anomaly, close to Brazopolis), Brazil, to study the day-to-day variability in the development of ionospheric plasma bubbles during both geomagnetically disturbed and quiet periods in September - October, 2002. Also, we present simultaneous complementary phase fluctuation (ROT) data obtained from the GPS (Global Position System) meridional chain operated by the Brazilian Institute of Geography and Statistic - 'IBGE'. On the three nights studied in the present investigation (one geomagnetically quiet and two geomagnetically disturbed) it has been observed that the geomagnetic disturbances, during this spring-equinox period, have a strong effect on the generation and development of ionospheric plasma bubbles.
[en] During attitude determination using a global positioning system (GPS), cycle slips occur due to the loss of lock and noise disturbance. Therefore, the integer ambiguity needs re-computation to isolate the error in carrier phase. This paper presents a fast method for integer ambiguity resolution for land vehicle application. After the cycle slips are detected, the velocity vector is utilized to obtain the rough baseline vector. The obtained baseline vector is substituted into carrier phase observation equations to solve the float ambiguity solution which can be used as a constraint to accelerate the integer ambiguity search procedure at next epochs. The probability of correct integer estimation in the expanded search space is analyzed. Experimental results demonstrate that the proposed method gives a fast approach to obtain new fixed ambiguities while the regular method takes longer time and sometimes results in incorrect solutions
[en] In this paper, a distributed method to estimate satellite and receiver differential code biases (DCBs) separately utilizing a network of global positioning system (GPS) receivers is proposed. The proposed method consists of many local filters and a single fusion module. Each local filter estimates vertical ionospheric delays (VIDs) and the combined DCBs (CDCBs) by utilizing dual-frequency code and carrier-phase measurements from each receiver. The fusion module gathers the combined DCB estimates and their estimation errors from all the local filters. Then it discriminates the satellite DCBs (SDCBs) and the receiver DCBs (RDCBs) separately. By an experiment, it is shown that the RMS difference of SDCBs and RDCBs between the proposed method and the IGS product are around 0.374 m and 0.424 m, respectively. (paper)
[en] Complete text of publication follows. The search for earthquake precursors, which can be used towards successful prediction of catastrophic earthquakes, has been a challenging issue. The intensive monitoring in several seismic zones of the world have indicated number of seismic and other geophysical precursors including electrical resistivity and magnetization changes. There are some success stories of definite precursory changes prior to several moderate to large earthquakes but their prognostic values are still skeptical due to lack of sound theory which can explain the presence of precursors in certain cases and their absence in many other cases. The laboratory based dilatancy-diffusion model tends to provide the physical mechanism for such precursory changes. Given the optimism provided by dilatancy-diffusion model, phases of earthquake cycle is expected to produce precursory changes in number of geophysical parameters at well-defined simultaneous measurements of multi-interdisciplinary data like seismic, geophysical, electrical, magnetic and electromagnetic parameter has now been well recognized. Given this rationales, WIHG has established the first Indian Multi-Parametric Geophysical Observatory (MPGO) in central Himalaya which has been shown to be critically stressed to produce great earthquakes. The observatory is equipped with superconductivity gravimeter, magnetotelluric, overhauser magnetometer, triaxial fluxgate, ULF bands search coil magnetometers, besides the radon data logger, water level recorder and network of broad band seismometers and GPS. Despite the high precision of most modern equipments, isolation of stress induced perturbations continues to be a challenging issue. Present paper shall highlight the importance of fractal, principal component analysis as well as data adopted techniques of wavelet transform to isolate inter-planetory / terrestrial induced changes from tectonic perturbations. The presentation shall demonstrate the efficacy of these methods in identifying local perturbations in magnetization / resistivity changes associated with moderate earthquakes.
[en] In this paper we studied the effect of geomagnetic storm on Global Positioning System (GPS) derived total electron content (TEC) at low latitude Varanasi (Geomagnetic lat 140, 55' N, geomagnetic long 1540 E) during the period of May 2007 to April 2008. During this period 2 storms were found, which were occurred on 20 November 2007 and 9 March 2008. In this study vertical total electron content (VTEC) of single Pseudorandom Noise (PRN) and average of VTEC of same PRN before 10 days of storm, which is called background TEC, were used to see the effect of these storms on the variation of TEC. From this study this is found that during the storm of March 2008 the TEC increases in main phase of storm while in the case of November 2007 storm, TEC decreases during the main phase of storm but increases in the recovery phase (next day) of storm.
[en] Nowadays cars are equipped frequently with typical 400 mm long active AM/FM antennas mounted on top close to the rear windshield. In , we presented a novel capacitive coupled helical antenna with a height of only 140 mm which performs equivalent to such an 400 mm long antenna. In the next step the antenna height has been reduced to only 56 mm in order to be placed in a low 65 mm housing in combination with other decoupled antennas. The measured results for AM/FM are close to the performance of a whip antenna of 900 mm length. The GPS and SDARS antennas are realized in a combination of two table-formed ring structures with a maximum gain for LHCP at 2339 MHz with 2.9 dBi in zenith and with 5.2 dBi in zenith for RHCP at 1575 MHz with GPS. The VSWR of the cell phone antenna is below 3 for AMPS and PCS1900.
[en] This paper mainly using CPS technology to localization in the steel sheet pile implementing on the sea surveying. Combined with the Nantong ocean mouth artificial island project, analyzing the application of GPS using on the steel sheet pile implementing the localization during the navigational affairs project, and introducing the prime tasks of the steel sheet pile implementing the localization in detail, the specific procedures as well as the questions which should be paid attention in the work process and the methods of solving the questions, some useful experiences of GPS using in the localization of steel sheet pile implementing was provided. (authors)