scholarly journals Simulation of External Stray Light for FY-3C VIRR Combined with Satellite Orbit Attitude Model

2021 ◽  
Vol 13 (24) ◽  
pp. 5037
Author(s):  
Junyuan Zhao ◽  
Yuqing He ◽  
Xiuqing Hu ◽  
Weiqi Jin ◽  
Lijun Zhang ◽  
...  
Keyword(s):  
Satellite Orbit ◽  
Optical Scattering ◽  
Stray Light ◽  
Imaging Systems ◽  
Space Environment ◽  
Analysis Method ◽  
Light Generation ◽  
The Given ◽  
Attitude Model ◽  
Infrared Radiometer

Optical imaging systems mounted on a Sun-synchronous satellite are probably disturbed by stray light when working in the space environment. Existing research has shown that the Visible Infrared Radiometer (VIRR) onboard the FY-3C satellite is affected by external solar stray light radiation when imaging the ground. In this paper, based on analyzing the solar stray light generation mechanism, we propose a simulation and analysis method combined with the given satellite orbit attitude model to investigate the influence of external solar stray light on VIRR’s imaging quality. We use the FY-3C orbit parameters to obtain the variation pattern of the angles between the solar vector and the payload. Based on the VIRR mechanical structure and optical scattering model, light tracing is performed to investigate the spatial distribution of irradiation on the primary mirror. The results of the occurrence time and intensity of stray light obtained by the simulation are consistent with the actual data when imaging the ground, which verifies that the proposed method is a correct and effective way to investigate the regularity of the external stray light of on-orbit payload.

scholarly journals Review of progress in gathering, distributing and using satellite data for activities within COST 238 (PRIME)

1996 ◽  
Vol 39 (4) ◽  
Author(s):  
I. Kutiev ◽  
S. Stankov
Keyword(s):  
Satellite Data ◽  
Satellite Orbit ◽  
Testing Procedure ◽  
Satellite Orbits ◽  
Neutral Atmosphere ◽  
Recombination Rates ◽  
F Region ◽  
Field Lines ◽  
The Given ◽  
To Receive

Recent progress in using the satellite data for various PRIME purposes is briefly presented. The satellite data base is already in operation and contains data of local plasma and neutral atmosphere parameters taken from several ionospheric satellites. A method of tracing the locally measured parameters along the magnetic field lines down to hmF2 is developed using a theoretical F-region code. This method is applied to receive f0F2sat needed to test monthly median and instantaneous mapping methods. In order to reduce the uncertainties arising from the unknown photoionization and recombination rates, f0F2 is calibrated at one point on the satellite orbit with a Vertical Incident (VI) f0F2 and their ratio is then assumed constant along the whole satellite track over the PRIME area. The testing procedure for monthly median maps traces the measured plasma density down to a basic height of 400 km, where individual f0F2sat values are accumulated in every time/subarea bin within the given month, then their median is calibrated with the available medians from the VI ionosonde network. From all available satellite orbits over the PRIME area, 35 of them were found to pass over two VI ionosonde stations. The second station in these orbits was used to check the calculated f0F2sat with the measured VI f0F2. The standard deviation was found to be only 0.15 MHz.

scholarly journals Polymerization of Isobutylene in a Rotating Packed Bed Reactor: Experimental and Modeling Studies

2021 ◽  
Vol 11 (21) ◽  
pp. 10194
Author(s):  
Wenhui Hou ◽  
Wei Wang ◽  
Yang Xiang ◽  
Yingjiao Li ◽  
Guangwen Chu ◽  
...  
Keyword(s):  
Strong Dependence ◽  
Average Molecular Weight ◽  
Packed Bed ◽  
Packed Bed Reactor ◽  
Mixing Efficiency ◽  
Polymerization Temperature ◽  
Analysis Method ◽  
Rotating Speed ◽  
Rotating Packed Bed ◽  
The Given

Polymerization of isobutylene (IB) for synthesizing highly reactive polyisobutylene (HRPIB) is characterized by a complicated fast intrinsic reaction rate; therefore, the features of its products exhibit a strong dependence on mixing efficiency. To provide uniform and efficient mixing, a rotating packed bed was employed as a reactor for polymerization of IB. The effects of operating parameters including polymerization temperature (T), rotating speed (N) and relative dosage of monomers and initiating systems ([M]0/[I]0) on number-average molecular weight (Mn) of HRPIB were studied. HRPIB with Mn of 2550 g·mol−1 and exo-olefin terminal content of 85 mol% were efficiently obtained at suitable conditions as T of 283 K, N of 1600 rpm and [M]0/[I]0 of 49. Moreover, the Mn can be regulated by changing T, N and [M]0/[I]0. Based on the presumptive-steady-state analysis method and the coalescence–redispersion model, a model for prediction of the Mn was developed and validated, and the calculated Mn values agreed well with experimental results, with a deviation of ±10%. The results demonstrate that RPB is a promising reactor for synthesizing HRPIB, and the given model for Mn can be applied for the design of RPB and process optimization.

Experience with an imaging infrared radiometer in a simulated space environment

1996 ◽  
Author(s):  
Georg Siebes ◽  
Kenneth R. Johnson ◽  
Doug McAffee
Keyword(s):  
Space Environment ◽  
Infrared Radiometer

scholarly journals Study on Three-Dimensional Analysis Method of Radiation Dose of GEO Satellite

2019 ◽  
Vol 288 ◽  
pp. 02010
Author(s):  
Chunsheng Xu ◽  
Yang Zhang ◽  
Hui Liu ◽  
Yong Yang ◽  
Yongquan Xia
Keyword(s):  
Radiation Dose ◽  
Dimensional Analysis ◽  
Three Dimensional ◽  
Space Environment ◽  
Analysis Method ◽  
Reliability Design ◽  
Satellite Design ◽  
Geo Satellite ◽  
Depth Analysis ◽  
D Model

GEO satellite in orbit is greatly affected by the total radiation dose of space environment. In order to meet the requirements of satellite reliability design, radiation dose analysis is an important work in the process of satellite design. Previous radiation dose analysis is based on one-dimensional dose-depth analysis, or three-dimensional analysis, but over-simplified 3-D model may cause the analysis results deviated different from the reality. This paper presents a three-dimensional radiation dose analysis method based on the actual 3-D model of satellite. This method could analyze radiation dose with actual models, which could be automatically simplified according to needs. It could automatically extract the attribute information in the model and calculate the radiation dose value in each subspace

Formal Modeling and Verifying the TTCAN Protocol from a Probabilistic Perspective

2019 ◽  
Vol 28 (10) ◽  
pp. 1950177
Author(s):  
Xin Li ◽  
Jian Guo ◽  
Yongxin Zhao ◽  
Xiaoran Zhu
Keyword(s):  
Automotive Industry ◽  
Probabilistic Model ◽  
Formal Modeling ◽  
Model Checker ◽  
Analysis Method ◽  
System Matrix ◽  
Quantitative Analysis Method ◽  
Time Requirements ◽  
The Given ◽  
Transmission Windows

The time-triggered CAN (TTCAN) protocol has been widely used in the automotive industry to fulfil the safety and real-time requirements of the application. As an extension of the standard CAN protocol, the TTCAN protocol aims to guarantee a safe and deterministic communication by introducing time-triggered messages with respect to a global synchronized time, which are scheduled in independent transmission windows within the system matrix. However, the new features bring more difficulties in designing and verifying the reliable applications in the TTCAN network. In this paper, we first present a formal probabilistic model of the TTCAN protocol with a consideration of its novel features. A TTCAN system consisting of three parts, i.e., a system matrix, an arbitration and some nodes, is modeled as discrete Markov chains model. Furthermore, five probabilistic properties are described and verified in the probabilistic model checker tool PRISM. Our work gives a quantitative analysis method for the given requirements, which facilitates the designers to a formal understanding of TTCAN protocol.

End of Life and Beginning of Life Thermal Analysis of a Micro Satellite

2015 ◽  
Vol 798 ◽  
pp. 551-555
Author(s):  
Mustafa Turkmenoglu
Keyword(s):  
Thermal Analysis ◽  
Thermal Degradation ◽  
End Of Life ◽  
Satellite Orbit ◽  
Thermal Control ◽  
Low Earth Orbit ◽  
Space Environment ◽  
Bottom Surface ◽  
Solar Panels ◽  
Space Environments

Satellites with passive thermal control system use thermal coatings, secondary and first surface mirrors and paints to maintain the temperatures of their electronic equipment within operating temperatures. Satellite coatings are exposed to harsh space environments like ultraviolet radiation (UV) and atomic oxygen (AO) that cause thermal degradation. As nature of the space environment, degradation of the surface paints and coatings cause increase in temperatures of the equipment in time. Thermal designer must consider the thermal degradation of the coatings and paints and optimize the radiator sizes of the satellite at Beginning of Life (BOL) and End of Life (EOL) of the satellite in order to maintain the temperatures of equipment within their safe operation limits. For this analysis, a micro-class satellite using passive thermal control with surface paints and interface conductance within each equipment has been studied. The satellite top surface (+Z) faces the earth and bottom surface (-Z) faces deep space. The lateral sides of the satellite are covered with honeycomb solar panels and top and bottom surfaces are covered with white paint which act as satellite radiator. The satellite orbit has been considered as 700 km Sun-Synchronous Low Earth Orbit. In this analysis BOL and EOL thermo optical properties have been used to predict the satellite temperatures before and after degradation of paints. Thermal analysis have been performed and predicted temperatures obtained by using THERMICA thermal analysis software.

OPTICAL SIGNAL ANALYSIS AND PROCESSING OF OPTICAL IMAGING WITH STRAY LIGHT BEAMS

2010 ◽  
Vol 21 (09) ◽  
pp. 1183-1195
Author(s):  
YING LIU ◽  
YUANPING ZHOU ◽  
WEIGUO WANG ◽  
WENMING TANG
Keyword(s):  
Optical Imaging ◽  
Signal Analysis ◽  
Optical Signal ◽  
Optical Image ◽  
Stray Light ◽  
Analysis Method ◽  
Image Edge ◽  
The Mean ◽  
The Difference ◽  
Light Beams

For the optical signal analysis and processing of optical imaging with stray light beams, a new analysis method for smoothing the optical image edge and maintaining the spectrum signal well is presented in this paper. By calculating the mean gray value of the light pixel in the filter window of adaptive algorithm, we can analyze and compare the difference between the mean gray value and the current gray value with the light pixel of stray light beams, and can determine the smoothness of the optical image edge. This method can increase greatly the ability of optical image analysis and processing, and effectively reduce the false edge and the edge loss for the optical imaging with stray light beams, so that the optical image with high quality can be obtained.

Stray Light Measurement For Imaging Systems

1988 ◽  
Vol 27 (1) ◽  
Author(s):  
Joseph M. Yaeli
Keyword(s):  
Stray Light ◽  
Imaging Systems ◽  
Light Measurement

scholarly journals Analysis of Consumer Attitudes and Performance Attributes of Various Processed Milkfish in Glagah District, Lamongan Regency, East Java

2021 ◽  
Vol 009 (01) ◽  
pp. 101-114
Author(s):  
Ika Purnamasari ◽  
◽  
Moch Saad ◽  
Keyword(s):  
Data Analysis ◽  
Positive Attitude ◽  
Descriptive Analysis ◽  
Consumer Attitudes ◽  
Business Development ◽  
Analysis Method ◽  
Product Packaging ◽  
Ease Of Access ◽  
And Performance ◽  
Attitude Model

Consumers are holders of important information in the management and planning of business development. The purpose of the study is to analyze consumer attitudes towards various processed milkfish and analyze the performance of product attributes of various processed milkfish in Glagah District, Lamongan Regency. The data analysis method used is descriptive analysis, Fishbein attitude model and Importance Performance Analysis (IPA). The results showed that the respondent's assessment of the processed otak-otak and smoked milkfish stated a neutral attitude, and the respondent's assessment of the shredded milkfish and crackers stated a positive attitude. The performance attributes of various processed milkfish included in quadrant I measure the processed otak-otak and the processed abon. Attributes included in quadrant II are taste and price for processed otak-otak, smoked, and crackers, while shredded milkfish only have tasted attributes. Attributes included in quadrant III are product packaging and ease of access for all kinds of milkfish preparations. Attributes included in quadrant IV are the size of the product for shredded and milkfish crackers. It does recommend that producers of otak-otak and smoked milkfish improve their products to get a positive attitude from customers.

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