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	Effects of machine learning models and spatial resolution on land cover classification accuracy in Dali County, Shaanxi, China 期刊论文 OAI收割 INTERNATIONAL JOURNAL OF AGRICULTURAL AND BIOLOGICAL ENGINEERING, 2025, 卷号: 18, 期号: 1, 页码: 245-259 作者: Shi, Yu; Jin, Ning; Wu, Bingyan; Wang, Zekun; Wang, Shiwen \| 收藏 \| 浏览/下载：21/0 \| 提交时间：2025/04/21 satellite data different spatial resolutions machine learning land use land cover random forest uncertainty
	GNSS time offset monitoring based on the single difference among systems 期刊论文 OAI收割 IET RADAR SONAR AND NAVIGATION, 2020, 卷号: 14, 期号: 2, 页码: 299-302 作者: Tu, Rui; Zhang, Pengfei; Zhang, Rui; Fan, Lihong; Liu, Jinhai \| 收藏 \| 浏览/下载：26/0 \| 提交时间：2020/11/09 delays satellite navigation radio receivers Global Positioning System GNSS time single difference time offset monitoring multiple Global Navigation Satellite Systems compatibility interoperability conventional signal space approaches single-point positioning SPP precise point positioning single-difference point positioning SDPP receiver clock parameter common model errors estimated time smooth estimation time offset estimation different stations system biases
	Variation of dependence of the cusp location at different altitude on the dipole tilt 期刊论文 OAI收割 CHINESE SCIENCE Bulletin, 2013, 卷号: 58, 期号: 28-29, 页码: 3541-3545 GUO JianGuang; SHI JianKui; CHENG ZhengWei; ZHANG ZiYing; WANG Zheng; ZHANG TieLong; LIU ZhenXing; DUNLOP Malcolm 收藏 \| 浏览/下载：46/0 \| 提交时间：2014/04/30 cusp location dependence dipole tilt altitude variation different satellite
	Retrieval of snow depth in Northeast China using FY-3B/MWRI passive microwave remote sensing data (EI CONFERENCE) 会议论文 OAI收割 Satellite Data Compression, Communications, and Processing VIII, August 12, 2012 - August 13, 2012, San Diego, CA, United states Ren R.; Gu L.; Chen H.; Cao J. 收藏 \| 浏览/下载：142/0 \| 提交时间：2013/03/25 Comparing with optical remote sensing techniques passive remote sensing data have been proved to be effective for observing snowpack parameters such as snow depth and snow water equivalent which can penetrate snowpack without clouds interferences. The Microwave Radiation Imager (MWRI) loaded on the Chinese FengYun-3B (FY-3B) satellite is gradually used in the global environment research through November 2011. In this paper we proposed a snow depth retrieval algorithm to estimate snow depth in Northeast China using MWRI passive microwave remote sensing data. A decision tree method of snow identification was firstly designed to distinguish different snow cover conditions in order to eliminate other interference signals. After using the proposed decision tree method the processing results were further used to retrieve the snow depth in Northeast China. Finally the practical snow depth data and the MODIS data were collected for the accuracy assessment of the proposed snow depth retrieval method. The experimental results demonstrated that the RMSE of snow depth used the proposed method was approximately 3 cm in Northeast China. 2012 SPIE.
	Design and calibration of the solar irradiance monitor (EI CONFERENCE) 会议论文 OAI收割 International Symposium on Photoelectronic Detection and Imaging 2011: Space Exploration Technologies and Applications, May 24, 2011 - May 26, 2011, Beijing, China 作者: Yang D.-J.; Gong C.-H.; Wang Y.-P. 收藏 \| 浏览/下载：38/0 \| 提交时间：2013/03/25 The solar irradiance monitor (SIM) with the design accuracy of 5 used to monitor the secular changes of the total solar irradiance on FY-3 satellite takes the sun-scanning measurement method on-orbit. Compared to the sun-tracking measurement method this method simplifies the structure and cuts the cost but the measuring accuracy is affected by the sun-synchronous orbit sunlight incidence angle and the installing angle of the SIM in the satellite. Through the ground calibration experiment studies on the affection of different sunlight incidence angles to the measurement accuracy. First by the satellite tool kit (STK) simulation software simulates the orbital parameters of the sun-synchronous satellite and calculates the Sun ascension and declination at any time. By the orbit coordinate transformation matrix gets the components of the Sun vectors to the axes of the satellite and base on the components designs the field of view and the installing angles of the SIM. Then designs and completes the calibration experiment to calibrate the affection of the incidence angles. Selecting 11 different angles between the sunlight and the satellite X-axis measures the total solar irradiance by the SIM at each angle and compares to the irradiances of the SIAR reference radiometers and gets the coefficient curves of the three channels of the SIM. Finally by the quadratic fitting gets the correction equations on the incidence angles: R 1=5.7110-52 -2.45310 -3+1.0302 R2=2.8410-5-1. 96510-3+1.0314 and R3 =1.7210 -52-4.18410-4+0.9946. The equations will aimprove the on-orbit measurement accuracy of the solar irradiance and are very important to the on-orbit data processing after the satellite launched. 2011 SPIE.
	Design of data transmission speed for small high resolution satellite (EI CONFERENCE) 会议论文 OAI收割 2011 International Conference on Transportation, Mechanical, and Electrical Engineering, TMEE 2011, December 16, 2011 - December 18, 2011, Changchun, China Wang S.; Jin G. 收藏 \| 浏览/下载：26/0 \| 提交时间：2013/03/25 The particular data-transmission time of one small satellite in its data-receiving stations is given by simulateing its orbit and data-receiving stations on earth and the average data-transmission speed is calculated. The average data-transmission speed is taken as the lower limit of speed other different data-transmission speeds are selected and simulated respectively the rule of satellite memory used is found. Basing on the relationship between data-transmission speed and memory on board and considering the worst case the better speed arrived. In the end with different satellite tasks the appropriate speeds are selected which are verified to satisfy the mission. 2011 IEEE.
	Embedded system of time uniform based on DSP (EI CONFERENCE) 会议论文 OAI收割 2010 International Conference on Computer, Mechatronics, Control and Electronic Engineering, CMCE 2010, August 24, 2010 - August 26, 2010, Changchun, China 作者: Li N.; Liu C.-X.; Liu C.-X.; Chen J.; Guo L.-H. 收藏 \| 浏览/下载：28/0 \| 提交时间：2013/03/25 We introduced a design method of DSP-based System of time uniform which combine the GPS and the Compass to calibrate the time. The system can use UTC (Coordinated Universal Time) of the GPS or the Compass for time base to generate absolute time and different frequency of synchronous signals. We used DSP (Digital Signal Processor) to calculate the satellite information which includes the UTC time. After getting the UCT time information put it into the CPLD (Complex Programmable Logic Device) for correction of time delay and serialization to output. Meanwhile we divided 1PPS (one-pulse-per-second) signal of the GPS and the Compass into 20Hz 50Hz and 800Hz synchronous signal. And we analyzed the precision of time and frequency. To conclude the uncertainty of system absolute time is less than 100ns the uncertainty of system synchronous signals is less than 20ns. This system is easy and flexible for use stable and reliable in performance. 2010 IEEE.
	Influence of the TDI CCD camera takes pictures when high resolution satellite lateral swaying (EI CONFERENCE) 会议论文 OAI收割 2009 IEEE International Conference on Mechatronics and Automation, ICMA 2009, August 9, 2009 - August 12, 2009, Changchun, China 作者: Zhang L.; Zhang L.; Sun Z. 收藏 \| 浏览/下载：20/0 \| 提交时间：2013/03/25 When the satellite was swinging and taking lateral imaging the TDI CCD pixel photovoltaic charge purses transferred velocity not matched with the image motion velocity. According to the requirement of high-resolution satellite which was taking lateral imaging at a low orbit the factors that bring about the unmatched phenomenon were analysed inclusive of the Earth's rotation the Earth curvature satellite attitude change measurement error and the installation error etc. Image motion errors caused by various factors were analysed and solved and the different characters of image motion errors were synthesized. Finally the total errors on the impact of imaging system MTF was analyzed. 2009 IEEE.