scholarly journals In-Situ Environmental Gamma Radiation Monitoring at Ramna Thana, Dhaka, Bangladesh

2019 ◽  
Vol 11 (3) ◽  
pp. 263-272
Author(s):  
M. S. Mian ◽  
M. S. Rahman ◽  
J. Islam ◽  
K. N. Sakib ◽  
M. M. Tasnim ◽  
...  
Keyword(s):  
Gamma Radiation ◽  
Global Positioning System ◽  
Annual Effective Dose ◽  
Natural Radionuclides ◽  
Outdoor Environment ◽  
Dose Rates ◽  
Gps Navigation ◽  
Sampling Locations ◽  
Global Positioning

Environmental gamma radiation dose rates were measured using a digital portable Gamma-Scout detector from April-May 2018. For this, total 22 monitoring points (MP) were selected in the outdoor environment in the area of Ramna Thana under Dhaka city. The MPs were marked-out using Global Positioning System (GPS) navigation. The GPS reading of the sampling locations were varied from E: 90o23.568' to E: 90o24.895' and from N: 23o44.031' to N: 23o45.018'. The measured dose rates due to natural radionuclides were ranged from 0.115 ± 0.042 µSv.hr-1 to 0.186 ± 0.051 µSv.h-1 with an average of 0.145 ± 0.044 µSv.h-1. The annual effective dose to the population from outdoor environmental gamma radiation was varied from 0.201 ± 0.073 mSv to 0.326 ± 0.090 mSv with an average of 0.255 ± 0.073 mSv. This kind of study is required to detect the presence of natural radionuclides and artificial radionuclides (if any) releasing from nuclear and radiological facilities in the country or from neighboring countries for normal operations or in case of accident/incident. From this study, it can be concluded that there is no radiation burden to the environment due to man-made sources.

scholarly journals Real-Time Environmental Gamma Dose Rates Measurement and Evaluation of Annual Effective Dose to population of Shahbag Thana, Dhaka, Bangladesh

2018 ◽  
Vol 6 (04) ◽  
Author(s):  
Shamsad Tazmin ◽  
Dr. Mohammad Sohelur Rahman ◽  
Selina Yeasmin ◽  
Dr. M. Habibul Ahsan ◽  
Md. Mahfuzzaman
Keyword(s):  
Gamma Radiation ◽  
Effective Dose ◽  
Dose Rate ◽  
Annual Effective Dose ◽  
Natural Radionuclides ◽  
Outdoor Environment ◽  
Acquisition Time ◽  
Population Exposure ◽  
Monitoring Point ◽  
Dose Rates

Background: In this study, environmental gamma radiation dose rates were measured in the area of Shahbag Thana under Dhaka city, Bangladesh. Aim of the study: This kind of study is required to detect the presence of natural and artificial radionuclides (if any) releasing from nuclear facilities in the country or from neighbouring countries. Materials and Method: The measurement was performed using a digital portable Gamma-Scout detector. The digital portable Gamma-Scout detector was placed at 1 meter above the ground on tripod and data acquisition time for each monitoring point (MP) was 1 hour. Total 27 MPs were selected for collection of gamma-ray dose rate in the outdoor environment of Shahbag Thana. The measurements were performed during light day from January to September 2017. The MPs were marked-out using Global Positioning System (GPS) navigation. The GP Sreading of the sampling locations were varied from E: 90˚23'32.94" to E: 90˚24'31.32" and from N:23˚44'19.38" to N: 23˚43'24.3". Results: The measured dose rates due to natural radionuclides were ranged from 0.085 ± 0.0245µSv.h-1 to 0.190526 ± 0.081886 µSv.h-1 with an average of 0.145265 ± 0.025192 µSv.h-1.The annual effective dose to the population from outdoor environmental gamma radiation was varied from0.104244 ± 0.030041 mSv  to 0.233661085 ± 0.100425 mSv. The range of dose rate and annual effective dosedue to outdoor environmental gamma radiation is lower than some countries like India, Sweden, China, CzechRepublic, Italy and higher than Canada, Turkey, Indonesia, Belgium, Albania, New Zealand and some other counties. Conclusion: From this study, it was observed that there is no burden of population exposure due to man-made sources. Therefore, it can be concluded that adequate safety and radiation protection of radiological facilities had been ensured which is required for minimizing of unnecessary exposure to populations from man-made sources. The estimated mean annual effective dose found in this study is not expected to contribute significant additional hazard from the radiological health point of view.

scholarly journals Measurement of Environmental Gamma Dose at AECD Campus of Bangladesh

2014 ◽  
Vol 6 (2) ◽  
pp. 285-291 ◽  
Author(s):  
M. S. Rahman ◽  
M. A. Islam ◽  
A. Begum ◽  
M. M. Rahman ◽  
M. H. Ahsan
Keyword(s):  
Dose Rate ◽  
Global Positioning System ◽  
Hpge Detector ◽  
Gamma Ray ◽  
Gamma Dose ◽  
Positioning System ◽  
Gps Navigation ◽  
Global Positioning ◽  
Measured Dose

A portable HPGe detector has been employed to assess environmental gamma-ray dose following in-situ technique from the primordial radionuclide 40K in the soil at 15 monitoring points (MPs) in the environment at the Atomic Energy Centre, Dhaka (AECD) campus, Bangladesh. The MPs were marked-out using Global Positioning System (GPS) navigation. The measured dose rate due to 40K range from 0.0428 µGy.h-1 to 0.1222 µGy.h-1 with an average of 0.0828 ± 0.0225 µGy.h-1. Keywords: Gamma; Environment; Dose rate.© 2014 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. doi: http://dx.doi.org/10.3329/jsr.v6i2.17146 J. Sci. Res. 6 (2), 285-291 (2014)  

Study on GPS Navigation Navigation System

2014 ◽  
Vol 556-562 ◽  
pp. 3313-3316
Author(s):  
Hao Ran Song
Keyword(s):  
Global Positioning System ◽  
Navigation System ◽  
Systems Design ◽  
Design System ◽  
Factors Affecting ◽  
Gps Navigation ◽  
Communications Technologies ◽  
Global Positioning ◽  
Depth Study ◽  
System Requirements

Currently, GPS global positioning system has been in the areas of precise positioning, navigation, timing has been widely used. By GPS-OEM combined with computer and communications technologies, users are able to easily and independently developed to meet the specific needs of GPS systems. Design system based on GPS navigation navigation system requirements package, in-depth study of the main factors affecting the precision of navigation. Several factors made corresponding solutions, implements navigation navigation system the main functions of the software.

scholarly journals Spatial distribution of gamma radiation dose rates from natural radionuclides and its radiological hazards in sediments along river Iju, Ogun state Nigeria

MethodsX ◽  
2020 ◽  
Vol 7 ◽  
pp. 101086
Author(s):  
Omeje Maxwell ◽  
Adewoyin Olusegun O. ◽  
Joel Emmanuel S. ◽  
Ikechukwu Ijeh B. ◽  
Omeje Uchechukwu A. ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Radiation Dose ◽  
Gamma Radiation ◽  
Natural Radionuclides ◽  
Dose Rates ◽  
Ogun State ◽  
Radiological Hazards ◽  
Gamma Radiation Dose

scholarly journals In situ conservation of fruit landraces

2010 ◽  
Vol 46 (Special Issue) ◽  
pp. S57-S59 ◽  
Author(s):  
F. Paprštein ◽  
J. Sedlák ◽  
V. Holubec
Keyword(s):  
Global Positioning System ◽  
Natural Habitat ◽  
In Situ Conservation ◽  
Sour Cherry ◽  
Ex Situ ◽  
The Czech Republic ◽  
Fruit Species ◽  
Global Positioning ◽  
Berry Fruits

<I>In situ </I>conservation is considered as conservation of wild biota in the natural habitat (locality). The authors extend the term to cultivated fruit species naturalised in the landscape, such as occasional spontaneous seedlings, and planted material such as old solitary trees among fields, old groves, avenues (country lanes), wind-breaks, and abandoned remnants of orchards. <I>In situ </I>conservation is also used to mark unique materials during collecting expeditions, before they will be taken as <I>ex situ </I>or proclaimed as permanent <I>in situ</I>. Important landraces found within 12 regions of the Czech Republic were registered, evaluated, and <I>in situ </I>localised by Global Positioning System (GPS). The following accessions were marked for in-situ conservation: apple (401), sweet cherry (263), pear (91), plum (42), sour cherry (27), and berry fruits (18).

scholarly journals An Intercomparison of GPS RO Retrievals with Colocated Analysis and In Situ Observations within Tropical Cyclones

2010 ◽  
Vol 2010 ◽  
pp. 1-10 ◽  
Author(s):  
Henry R. Winterbottom ◽  
Qingnong Xiao
Keyword(s):  
Tropical Cyclones ◽  
Global Positioning System ◽  
Global Analysis ◽  
Reanalysis Data ◽  
Satellite Mission ◽  
Data Set ◽  
Global Positioning ◽  
In Situ Observations ◽  
Atmospheric State

Observations from four Global Position System (GPS) Radio Occultation (RO) missions: Global Positioning System/Meteorology, CHAallenging Minisatellite Payload, Satellite de Aplicaciones Cientificas-C, and Constellation Observing System for Meteorology, Ionosphere and Climate and Taiwan's FORMOsa SATellite Mission #3 (COSMIC/FORMOSAT-3) are collected within a 600 km radius and ±180 minute temporal window of all observed tropical cyclones (TCs) from 1995 to 2006 that were recorded in the global hurricane best-track reanalysis data set (Jarvinen et al. (1984); Davis et al. (1984)). A composite analysis of tropical cyclone radial mean temperature and water vapor profiles is carried out using the GPS RO retrievals which are colocated with global analysis profiles and available in situ radiosonde observations. The differences between the respective observations and analysis profiles are quantified and the preliminary results show that the observations collected within TCs correspond favorably with both the analysis and radiosonde profiles which are colocated. It is concluded that GPS RO observations will contribute significantly to the understanding and modeling of TC structures, especially those related to vertical variability of the atmospheric state within TCs.

scholarly journals Characterization of the Long-term Radiosonde Temperature Biases in the Lower Stratosphere using COSMIC and Metop-A/GRAS Data from 2006 to 2014

2016 ◽  
Author(s):  
Shu-Peng Ho ◽  
Liang Peng ◽  
Holger Vömel
Keyword(s):  
Global Positioning System ◽  
Lower Stratosphere ◽  
Temperature Measurements ◽  
Global Trend ◽  
Global Positioning ◽  
The Mean ◽  
Geographical Locations

Abstract. Radiosonde observations (RAOBs) have provided the only long-term global in situ temperature measurements in the troposphere and lower stratosphere since 1958. In this study, we use consistently reprocessed Global Positioning System (GPS) radio occultation (RO) temperature data derived from COSMIC and Metop-A/GRAS missions from 2006 to 2014 to characterize the inter-seasonal and inter-annual variability of temperature biases in the lower stratosphere for different sensor types. The results show that the RAOB temperature biases for different RAOB sensor types are mainly owing to i) uncorrected solar zenith angle dependent errors, and ii) change of radiation correction. The mean daytime temperature difference (ΔT) for Vaisala RS92 is equal to 0.18 K in Australia, 0.20 K in Germany, 0.10 K in Canada, 0.13 K in England, and 0.33 K in Brazil. The mean daytime ΔT is equal to −0.06 K for Sippican, 0.71 K for VIZ-B2, 0.66 K for AVK-MRZ, and 0.18 K for Shanghai. The daytime trend of anomalies for Vaisala RS92 and RO temperature at 50 hPa is equal to 0.00 K/5 yrs over United States, −0.02 K/5 yrs over Germany, 0.17 K/5 yrs over Australia, 0.23 K/5 yrs over Canada, 0.26 K/5 yrs over England, and 0.12 K/5 yrs over Brazil, respectively. Although there still exist uncertainties for Vaisala RS92 temperature measurements over different geographical locations, the global trend of temperature anomaly between Vaisala RS92 and RO from June 2006 to April 2014 is within +/−0.09 K/5 yrs globally. Comparing with Vaisala RS80, Vaisala RS90 and sondes from other manufacturers, the Vaisala RS92 seems to provide the best RAOB temperature measurements, which can potentially be used to construct long term temperature CDRs. Results from this study also demonstrate the feasibility to use RO data to correct RAOB temperature biases for different sensor types.

scholarly journals Robust Huber-Based Cubature Kalman Filter for GPS Navigation Processing

2016 ◽  
Vol 70 (3) ◽  
pp. 527-546 ◽  
Author(s):  
Chien-Hao Tseng ◽  
Sheng-Fuu Lin ◽  
Dah-Jing Jwo
Keyword(s):  
Kalman Filter ◽  
Global Positioning System ◽  
Unscented Kalman Filter ◽  
Measurement Information ◽  
Gps Navigation ◽  
Cubature Kalman Filter ◽  
Global Positioning ◽  
M Estimation ◽  
Non Gaussian ◽  
Distribution Assumption

A robust state estimation technique based on the Huber-based Cubature Kalman Filter (HCKF) is proposed for Global Positioning System (GPS) navigation processing. The Cubature Kalman Filter (CKF) employs a third-degree spherical-radial cubature rule to compute the Gaussian weighted integration, such that the numerical instability induced by round-off errors can be avoided. In GPS navigation, the filter-based estimation of the position and velocity states can be severely degraded due to contaminated measurements caused by outliers or deviation from a Gaussian distribution assumption. For the signals contaminated with non-Gaussian noise or outliers, a robust scheme combining the Huber M-estimation methodology and the CKF framework is beneficial where the Huber M-estimation methodology is used to reformulate the measurement information of the CKF. GPS navigation processing using the HCKF algorithm has been carried out and the performance has been compared to those based on the Extended Kalman Filter (EKF), Unscented Kalman Filter (UKF) and CKF approaches. Simulation and experimental results presented in this paper confirm the effectiveness of the method.

scholarly journals Ice tectonic deformation during the rapid in situ drainage of a supraglacial lake on the Greenland Ice Sheet

2013 ◽  
Vol 7 (1) ◽  
pp. 129-140 ◽  
Author(s):  
S. H. Doyle ◽  
A. L. Hubbard ◽  
C. F. Dow ◽  
G. A. Jones ◽  
A. Fitzpatrick ◽  
...  
Keyword(s):  
Global Positioning System ◽  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Tectonic Deformation ◽  
Positioning System ◽  
Differential Motion ◽  
Global Positioning ◽  
Lake Drainage ◽  
Lake Record

Abstract. We present detailed records of lake discharge, ice motion and passive seismicity capturing the behaviour and processes preceding, during and following the rapid drainage of a 4 km2 supraglacial lake through 1.1-km-thick ice on the western margin of the Greenland Ice Sheet. Peak discharge of 3300 m3 s−1 coincident with maximal rates of vertical uplift indicates that surface water accessed the ice–bed interface causing widespread hydraulic separation and enhanced basal motion. The differential motion of four global positioning system (GPS) receivers located around the lake record the opening and closure of the fractures through which the lake drained. We hypothesise that the majority of discharge occurred through a 3-km-long fracture with a peak width averaged across its wetted length of 0.4 m. We argue that the fracture's kilometre-scale length allowed rapid discharge to be achieved by combining reasonable water velocities with sub-metre fracture widths. These observations add to the currently limited knowledge of in situ supraglacial lake drainage events, which rapidly deliver large volumes of water to the ice–bed interface.

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