Double Station Research Articles

Design of gas flow standard facility for continuous detection with two stations

The traditional gas flow standard facility can only carry out single station detection, so it is urgent to solve the problem of improving work efficiency. In this paper, the existing gas flow standard facilities and related technologies are studied in depth, especially for the same specifications, batch detection table, the design of double station continuous detection type gas flow standard facilities. Its main features are: according to the need to flexibly choose two stations alternating detection, two stations at the same time detection or single station detection mode, under the premise of ensuring the safety and reliability of the facility, greatly improve the work efficiency. In this paper, the operation process and flow diagram of the three detection methods are given in detail, and the applicability and improvement direction of the facility are analyzed and prospected. This facility design work efficiency enhancement advantage is significant, has a good promotion value.

On the origin of the Southern Delta Aquariids meteor shower

We determine the begin and end heights of meteors to calculate and compare the median kB parameter (Ceplecha, 1967) of several meteor showers observed throughout 2013. This parameter gives an indication on the type of parent body from which meteor showers originate. We propose that the meteoroids giving rise to the Southern Delta Aquariids consist of high strength material, likely asteroidal, unlike most meteor showers. In particular their parent body could be a C-type asteroid. We discuss the potential candidates in the light of existing literature and conclude that it could be a combination of comet 96P and asteroid 2003 EH1, with a higher relative abundance of the asteroid. The following results are obtained using observations from CILBO, a double station meteor camera set-up in the Canary Islands. Meteors are detected with MetRec, a meteor detection software (Molau, 1999) and the characteristics of their trajectories are computed using the Meteor Orbit and Trajectory Software (Koschny and Rio, 2002).

The “Mobile Observation of Meteor” (MoMET) device

Meteor shower outbursts happen every year, but cannot be observed by a single meteor camera network. In addition, bad weather might prevent the recording of such event. In order to enable the observation of meteor shower outburst, we developed a “Mobile Observation of METeor” device. It involves two suitcases for meteor double station observations. Each case includes a total of 5 cameras to maximise the scientific output. Each camera is controlled by a mini-PC (RaspBerry pi or Odroid) and runs the “RMS” software (Vida et al. 2021, MNRAS, 506, 4, 5046). The MoMET devices were successfully used to record the 2021 Arids meteor shower from Chile.

FEASIBILITY STUDY OF WOOD WORKSHOP SPACES CONTRUCTION AND PROPERTY BUSINESS EXPERTISE STUDY AT STATE VOCATIONAL SCHOOL 1 PALANGKA RAYA

The purpose of this study was to determine the feasibility of the wood workshop space, wood workshop lighting system, and woodworking furniture and equipment at SMK N 1 Palangka Raya based on the standards required by Permendiknas No. 40 of 2008 and SNI 03-6575-2001. This is done to provide convenience and feasibility for users. The results of this study are (1) the wood workspace area of SMK N 1 Palangka Raya does not meet the standard with an area of 198 m² which is smaller than the standard of 256 m² with an achievement percentage of 77.34%, the area of the equipment storage room and the wood workshop instructor room has meet the standard with an area of 72 m² larger than the standard of 48 m² with an achievement percentage of 150%, the overall area of the wood workshop does not meet the standard with an area of 270 m² smaller than the standard of 304 m² with an achievement percentage of 88.8%. (2) The level of lighting in the wood workshop room at SMK N 1 Palangka Raya has not met the standard, namely min 500 lux with a lighting level of 400 lux in the morning with an achievement percentage of 80%, during the day 411 lux with an achievement percentage of 82%, in the afternoon day of 408 lux with an achievement percentage of 81%. (3) Equipment and furniture for the wood workshop room at SMK N 1 Palangka Raya, single station equipment does not meet the standard with the number of equipment that meets the standard is 1 type of tool and 20 types of tools that meet the standard with a size of achievement of 4.76%, equipment double station there are 3 types of tools that meet the standards and 9 types of tools that do not meet the standards with a size of 16.66% standard achievement, workshop furniture there are 3 types of furniture that do not meet the standards and 4 types of furniture that meet the standards with a large standard achievement are 42.85%.

RESULTS OF POSITIONAL AND PHOTOMETRIC MEASURE- MENTS OF METEOR TRAJECTORIES OBSERVED IN MYKOLAIV 2017-2018

Regular meteor observation using TV CCD unintensified techniques was started in 2011 in RI «Mykolaiv astronomical observatory» (RI MAO). The method of meteor registration is based on using “track- and-stack” technique for obtaining frames with reference stars and online meteor detection software developed at RI NAO. The main accent of the research is made on precise astrometry and meteoroid orbits calculation. New observa- tional campaign with baselines 11.7 and 100 km was start- ed in 2017-2018 in collaboration with Astronomical Ob- servatory of the I.I. Mechnikov Odessa National Universi- ty. Eight telescopes with narrow field lens (f=50 mm, f/1.2) were installed in Mykolaiv and Odessa. More than 3000 single station meteors and 221 double station mete- ors were detected during 2017-2018. Uncertainties of me- teor trajectory and orbital parameters are calculated using Monte Carlo method. Catalog of meteor trajectory posi- tions and photometric parameters has created. Standard deviation of approximation of a meteoric trajectory in a large circle is (15-20). Kinematic parameters of atmos- pheric meteoric trajectories and elements of heliocentric orbits for 3 meteors were calculated based on the results of television observations with cameras with a field of view <10° at a baseline distance 100 km. The average uncertainty of visible radiant estimation is in (0.3-0.7)o with baseline 100 km. The geocentric velocity estimation uncertainty is 0.5 km/s, elevation uncertainty is 50-150 m.

Hybrid Detection of High Energy Showers in Urban Environments

The Astroneu array comprises 9 large charged particle detectors and 3 RF antennas arranged in three autonomous stations operating at the University Campus of the Hellenic Open University in the city of Patras. Each station of the array detects extensive air showers with primary energy threshold of about 10 TeV, while double station coincidence events select showers with energies higher than 10 3 TeV. In such an environment, the radio detection of air showers is challenging. The RF signals besides being extremely weak they also suffer from strong human made electromagnetic noise. In this work, we present the analysis of double station coincidence events and we study the correlation of the RF data with the particle detectors data. We use the experimental information from the particle detectors and the antennas to select very high energy showers and we compare the timing of the RF signals with the timing of the particle detector signals as well as the strength of the RF signals with the simulation predictions.

RADIANTS AND ORBITAL DISTRIBUTION OF TV FAINT SPORADIC METEORS

Double station meteor observation using TV CCD unintensified techniques was started in 2013 in Nikolaev astronomical observatory (RI NAO). During observational campaign in 2013-2016 catalog containing 1055 meteoroid orbits has been obtained. Registered meteoroid photometric masses (Kruchinenko, 2012) are between 10 -7 and 10 - 2 kg. Distribution of radiants, velocities and elements of heliocentric orbits with accent on meteoroids with low masses are analyzed in the work. Comparison with data from meteoroid orbit catalogs SonotaCo, EDMOND and NFC networks is also given. Two kinds of databases/catalogs are distinguished: “narrow field” and “wide field” depending on which type of camera system were used in observations. For analysis of the different catalogs only sporadic meteors were selected. Comparison of sporadic meteoroid radiants and orbital elements for different databases has shown that “narrow field” observations have next typical characteristics: 1) more relative number of low-mass meteoroids (about 30%) than large databases obtained by wide-angle observations; 2) significant increasing of number of low-velocity ( V g 4.6 predominantly; 3) low-mass meteoroids in “wide-field” databases caused Apex contribution only, notable part of this objects from “narrow-field” data has radiants close to Antihelion source.

Observations of meteors in the Earth’s atmosphere: Reducing data from dedicated double-station wide-angle cameras

Meteoroids entering the Earth’s atmosphere can be observed as meteors, thereby providing useful information on their formation and hence on their parent bodies. We developed a data reduction software package for double station meteor data from the SPOSH camera, which includes event detection, image geometric and radiometric calibration, radiant and speed estimates, trajectory and orbit determination, and meteor light curve recovery. The software package is designed to fully utilise the high photometric quality of SPOSH images. This will facilitate the detection of meteor streams and studies of their trajectories. We have run simulations to assess the performance of the software by estimating the radiants, speeds, and magnitudes of synthetic meteors and comparing them with the a priori values. The estimated uncertainties in radiant location had a zero mean with a median deviation between 0.03∘ and 0.11∘ for the right ascension and 0.02∘ and 0.07∘ for the declination. The estimated uncertainties for the speeds had a median deviation between 0.40 and 0.45 km s−1. The brightness of synthetic meteors was estimated to within +0.01 m. We have applied the software package to 177 real meteors acquired by the SPOSH camera. The median propagated uncertainties in geocentric right ascension and declination were found to be of 0.64∘ and 0.29∘, while the median propagated error in geocentric speed was 1.21 km s−1.

The Intelligent Flexible Welding System for Robot Based on Double Station

In order to improve the production efficiency and reduce the cost of enterprise and promote the enterprise safety production. This paper presents an intelligent robot welding system which based on double station. It solves welding matched problems of different water main and different distributed water pipe for enterprise. Due to adopt the technology which simultaneous welding on both sides of the main pipe with double station. The influence of heat expansion on welding deformity of the main pipe is greatly reduced during the welding process. The motion control of whole set of intelligent welding control system consists of three parts. The motion control system for charging of the branch pipe and the control system of main water pipe and the robot welding control system. All motion control is unified centralized and synchronous control management in the central control room by PLC.

Long-Term Continuous Double Station Observation of Faint Meteor Showers.

Meteor detection and analysis is an essential topic in the field of astronomy. In this paper, a high-sensitivity and high-time-resolution imaging device for the detection of faint meteoric events is presented. The instrument is based on a fast CCD camera and an image intensifier. Two such instruments form a double-station observation network. The MAIA (Meteor Automatic Imager and Analyzer) system has been in continuous operation since 2013 and has successfully captured hundreds of meteors belonging to different meteor showers, as well as sporadic meteors. A data processing pipeline for the efficient processing and evaluation of the massive amount of video sequences is also introduced in this paper.

BDS relative static positioning over long baseline improved by GEO multipath mitigation

Due to the satellite and constellation deployment design, the variation pattern of multipath effect in BeiDou Navigation Satellite System (BDS) code observation is different from GPS. The amplitude of systematic multipath variation (SMV) exists in multipath combination series may exceed 0.5m for some geostationary earth orbit (GEO) satellites, which is larger than the normal noise level of GPS code observation. After characterization of the variation pattern of BDS multipath series for BDS GEO satellites, we propose to improve the performance of relative positioning over long baseline by mitigating the SMV effect of GEO satellite. The proposed method uses the SMV extracted from multipath (MP) combination series with adaptive wavelet transform as correction for current day observation in post-processing use or as following day correction in real-time use. In addition, the Double Station Observation Processing (DSOP) method that directly uses undifferenced observation is applied for relative static positioning. Experiment results show improvement in convergence speed for both BDS only and BDS/GPS combined solution.

Dynamic tracking performance of indoor global positioning system: An experimental and theoretical study

The automation level has been improved rapidly with the introduction of large-scale measurement technologies, such as indoor global positioning system, into the production process among the fields of car, ship, and aerospace due to their excellent measurement characteristics. In fact, the objects are usually in motion during the real measurement process; however, the dynamic measurement characteristics of indoor global positioning system are much limited and still in exploration. In this research, we focused on the dynamic tracking performance of indoor global positioning system and then successfully built a mathematical model based on its measurement principles. We first built single and double station system models with the consideration of measurement objects’ movement. Using MATLAB simulation, we realized the dynamic measurement characteristics of indoor global positioning system. In the real measurement process, the experimental results also support the mathematical model that we built, which proves a great success in dynamic measurement characteristics. We envision that this dynamic tracking performance of indoor global positioning system would shed light on the dynamic measurement of a motion object and therefore make contribution to the automation production.

Double station observation of Draconid meteor outburst from two moving aircraft

A Draconid meteor shower outburst was observed from the boards of two scientific aircraft on 8 October 2011. In this paper we report the results of this double station experiment. The beginning and terminal heights are similar to other Draconid observations and confirm the fragile nature of the meteoroids. From the distribution function of terminal heights, a critical mass was found to be about 3.5g. A behaviour of the terminal heights changes at this point. Light curves of Draconid meteors show great variability with a maximum of the F-number distribution around 0.35, which also confirms fragility of the material. Observed radiants of the meteors are in agreement with the theoretical model. Although encounters with two different filaments were predicted, it is impossible to distinguish between them from the radiants as well as the orbital data. Despite the complications with the data processing the airborne mission shows that such double station experiment is possible and provides valuable insight into meteor structure and dynamics.

The 2011 Draconids: The First European Airborne Meteor Observation Campaign

On 8 October 2011, the Draconid meteor shower (IAU $$\#8$$ , DRA) was predicted to cause two brief outbursts of meteors, visible from locations in Europe. For the first time, a European airborne meteor observation campaign was organized, supported by ground-based observations. Two aircraft were deployed from Kiruna, Sweden, carrying six scientists, 19 cameras and eight crew members. The flight geometry was chosen such that it was possible to obtain double-station observations of many meteors. The instrument setup on the aircraft as well as on the ground is described in full detail. The main peak from 1900-dust ejecta happened at the predicted time and at the predicted rate. The second peak was observed from the earlier flight and from the ground, and was caused most likely by trails ejected in the nineteenth century. A total of 250 meteors were observed, for which light curve data were derived. The trajectory, velocity, deceleration and orbit of 35 double station meteors were measured. The magnitude distribution index was high, as a result of which there was no excess of meteors near the horizon. The light curve proved to be extremely flat on average, which was unexpected. Observations of spectra allowed us to derive the compositional information of the Draconids meteoroids and showed an early release of sodium, usually interpreted as resulting from fragile meteoroids. Lessons learned from this experience are derived for future airborne meteor shower observation campaigns.

BDS/GPS relative positioning for long baseline with undifferenced observations

Before and after the official beginning of Beidou navigation satellite system (BDS) regional service on December 27, 2012, many applications based on BDS such as real-time kinematic (RTK) and precise point positioning (PPP) with real data have been considered in the literatures. However, lack of precise satellite antenna correction and relatively low quality of BDS orbit and clock product is an obstacle for PPP and relative positioning over long baseline using BDS observations. In this paper, the Double Station Observation Processing (DSOP) method that directly uses undifferenced data is applied to relative positioning. By estimating the satellite clock offsets on-the-fly, the satellite dependent unmodelled error can be compensated. Moreover, the direct use of undifferenced observation makes the method easy to implement and flexible to adapt observations of multiple systems. Experiment results demonstrate that relative positioning based on BDS observations can be achieved at centimeter accuracy level which is better than conventional PPP results with limited computation burden increase. These results also indicate the promising potential of BDS to develop real-time service.

Study on Engineering Materials with Results of the Analysis of the Influence of Foundation Pit Surrounding Buildings Settlement

In this project, some engineering materials will be used, such as reinforcing bar, commercial concrete. Because the site underground water level is higher, in order to prevent the surrounding buildings and roads happens the non-uniform settlement, the settlement must be observed, using single double station observation way, each settlement will draw up the curve, and according to the settlement curve for foundation pit precipitation to the influence of the architecture around the research.

一种基于相频函数关系的双基时差定位方法

基于相、频、时三者之间的函数关系，提出了一种有助于改善现有多站时差无源定位性能的定位算法。相对于现有的平面三站时差定位方法，这种先通过频移到相差的函数变换，再利用相差和时差间的关系，将原先仅能用于机载的测距公式转化为与探测平台运动状态无关的双基时差定位方法具有更高的测量精度，避免了对高重频信号测量的定位解模糊，同时相距较远的两主基站间的时间基准可以要求不同步，这无疑有利于站址的选择。仿真结果验证了该算法的有效性。 This paper presents a location algorithm which can help to improve existing performance of multistation time difference location based on the function relationship among phase shift, Doppler shift and time difference. New method uses the relationship between phase difference and time difference based on the function transforms from Doppler shift into phase shift. Finally, the ranging formula that only can apply to airborne platform can be translated into the double station time difference location method which is not associated with the motion state of detection platform. As compared to existing three stations time difference location method in two-dimension plane, the double station time difference location method can heighten measurement accuracy and avoid the time difference ambiguity introduced by high PRF signal. At the same time, it also has the characteristics that the time reference between two major base stations can be deranged, and that looking for the building position of base station is more convenient. Simulation result proves the availability of the algorithm.

Identification of radiants of low-light-level meteors from double station TV observations during autumnal equinox of 2001 and 2003

AbstractResults of double-station TV meteor observations which were carried out during autumnal equinox in 2001 and 2003 are used for the confirmation of existing meteor showers and for a search for probable new micro-showers. Seven existing September showers were confirmed, two of them by meteors from both years. Fourteen new groups were proposed to be considered as new meteor micro-showers. Taking into account similar kinematical parameters two of them can be supposed to be a part of already existing showers.

The Double-Station Fixture Based on Air-Liquid and Air-Liquid-Mechanical Composite Transmission Technology and its Application in Press

When adopting the air-liquid and air-liquid-mechanical composite transmission technology, the comparative advantages of various transmission techniques can be played, while their shortcomings can be avoided. The efficient fixture and press with double-station based on these composite transmission technology are introduced, and their working principles and mechanical formulas are given out. The innovative design of the fixture and press with double station can achieve the two station order-processing operations when only using one drive cylinder, which have high efficiency, the large output force, and will not pollute the environment.

Automatic Video System for Continues Monitoring of the Meteor Activity

In this paper we present current progress in development of new observational instruments for the double station video experiment. The Meteor Automatic Imager and Analyser (MAIA) system is based on digital monochrome camera JAI CM-040 and well proved image intensifier XX1332. Both the observations as well as the data processing will be fully automatic. We are expecting the recorded data of better quality and both spatial and time resolution in comparison with currently used analogue system. The main goal of the MAIA project is to monitor activity of the meteor showers and sporadic meteor each night for the period of at least 3 years. First version of the system was already assembled and has been intensively tested in the optical laboratory. Optical properties were measured and the result confirmed our expectations according to image quality and resolution. First night sky observation was already carried out.