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

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.

Adaptive output-feedback robust active disturbance rejection control for uncertain quadrotor with unknown disturbances

PurposeIn this research paper, an adaptive output-feedback robust active disturbance rejection control (RADRC) is designed for the multiple input multiple output (MIMO) quadrotor attitude model subject to unwanted uncertainties and disturbances (UUDs).Design/methodology/approachIn order to achieve the desired control objectives in the presence of UUDs, the low pass filter (LPF) and extended high gain observer (EHGO) methods are used for the estimation of matched and mismatched UUDs, respectively. Furthermore, for solving the chattering incurred in the standard sliding mode control (SMC), a multilayer sliding mode surface is constructed. For formulating the adaptive output-feedback RADRC algorithm, the EHGO, LPF and SMC schemes are combined using the separation principle.FindingsThe findings of this research work include the design of an adaptive output-feedback RADRC with the ability to negate the UUDs as well as estimate the unknown states of the quadrotor attitude model. In addition, the chattering problem is addressed by designing a modified SMC scheme based on the multilayer sliding mode surface obtained by utilizing the estimated state variables. This sliding mode surface is also used to obtain the adaptive criteria for the switching design gain parameters involved in the SMC. Moreover, the requirement of high design gain parameters in the EHGO is solved by combining it with the LPF.Originality/valueDesigning the flight control techniques while assuming that the state variables are available is a common practice. In addition, to obtain robustness, the SMC technique is widely used. However, in practice, the state variables might not be available due to unknown parameters and uncertainties, as well as the chattering due to SMC reduces the performances of the actuators. Hence, in this paper, an adaptive output-feedback RADRC technique is designed to solve the problems of UUDs and chattering.

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

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.

Pengaruh Brand Awareness, Perceived Quality dan Consumer Attitude terhadap Purchase Intention Produk Skin Care Telaah pada Konsumen Pria di Indonesia

This research is proposed to find out whether there is relationship between brand awareness, perceived quality, and consumer attitude, with purchase intention in Nivea Men Crème Product with 4 hypotheses that will be tested using the Structural Equation Model. The sample in this study consisted of 162 respondents who were men in Indonesia who had used, seen, and knew the Nivea brand. The result of the analysis that using AMOS ver.25 proven that brand awareness, perceived quality and consumer attitude simultaneously have an influence on Nivea Men Crème purchase intentions in Indonesian’s men market. Penelitian ini bertujuan untuk mengetahui apakah terdapat minat beli pria Indonesia terhadap produk Nivea Men Crème yang dipengaruhi oleh brand awareness, perceived quality dan consumer attitude. Model teoritis dalam penelitian ini disajikan dengan 4 hipotesis yang akan diuji menggunakan Structural Equation Model. Sampel dalam penelitian ini berjumlah 162 responden laki-laki di Indonesia yang pernah melihat, mengenal merek Nivea. Hasil analisis metode penelitian AMOS ver.25 (Paket Statistik Ilmu Sosial) membuktikan bahwa brand awareness, perceived quality dan consumer attitude secara simultan berpengaruh terhadap niat beli Nivea Men Crème di pasar pria Indonesia.

Impact of Attitude Model, Phase Wind-Up and Phase Center Variation on Precise Orbit and Clock Offset Determination of GRACE-FO and CentiSpace-1

Currently, low Earth orbit (LEO) satellites are attracting great attention in the navigation enhancement field because of their stronger navigation signal and faster elevation variation than medium Earth orbit (MEO) satellites. To meet the need for real-time and precise positioning, navigation and timing (PNT) services, the first and most difficult task is correcting errors in the process of precise LEO orbit and clock offset determination as much as possible. Launched in 29 September 2018, the CentiSpace-1 (CS01) satellite is the first experimental satellite of LEO-based navigation enhancement system constellations developed by Beijing Future Navigation Technology Co. Ltd. To analyze the impact of the attitude model, carrier phase wind-up (PWU) and phase center variation (PCV) on precise LEO orbit and clock offset in an LEO-based navigation system that needs extremely high precision, we not only select the CS01 satellite as a testing spacecraft, but also the Gravity Recovery and Climate Experiment Follow-On (GRACE-FO). First, the dual-frequency global positioning system (GPS) data are collected and the data quality is assessed by analyzing the performance of tracking GPS satellites, multipath errors and signal to noise ratio (SNR) variation. The analysis results show that the data quality of GRACE-FO is slightly better than CS01. With residual analysis and overlapping comparison, a further orbit quality improvement is possible when we further correct the errors of the attitude model, PWU and PCV in this paper. The final three-dimensional (3D) root mean square (RMS) of the overlapping orbit for GRACE-FO and CS01 is 2.08 cm and 1.72 cm, respectively. Meanwhile, errors of the attitude model, PWU and PCV can be absorbed partly in the clock offset and these errors can generate one nonnegligible effect, which can reach 0.02~0.05 ns. The experiment results indicate that processing the errors of the attitude model, PWU and PCV carefully can improve the consistency of precise LEO orbit and clock offset and raise the performance of an LEO-based navigation enhancement system.

A qualitative case study of Spelman College's students' attitude toward Spelman College's transgender admissions and enrollment policy and its transgender and gender non-conforming students

This qualitative case study examined 10 Spelman College's students' attitude toward its new transgender admissions and enrollment policy, as well as their attitudes toward Spelman's transgender and gender non-conforming students. This study was guided by Allport's (1935) Tricomponent Attitude Model and intersectionality theories, which was used to analyze their attitudes toward the policy and its students. Interviews were conducted and coded using six predetermined codes that were informed by the two research questions and the theoretical frameworks. This study found that most participants supported the policy; however, one participant that felt indifferent and another opposed it. Despite the participants' overwhelming support of the policy, many felt that the lack of understanding of the policy among students might fuel intolerance or opposition. Although participants felt that Spelman's policy was a step towards trans-inclusion, many questioned Spelman's readiness to welcome and support transgender and gender non-conforming students on its campus. Despite participants' overwhelming support for transgender and gender non-conforming students, many had concerns that students' intersectional identities regarding race, gender, religion, and geographical upbringing, coupled with Spelman's ties to Christianity, may create unwelcoming and hostile environments for transgender and gender non-conforming students.