Compared with the traditional examinations, the paperless examination of the computer elementary course can not only realize the assessment of the theoretical knowledge, but also can carry out the assessment of the ac...Compared with the traditional examinations, the paperless examination of the computer elementary course can not only realize the assessment of the theoretical knowledge, but also can carry out the assessment of the actual operations of some of the operational computer subjects, which can make it more comprehensive. Through the computer evaluation, we can make the results consistent, and get rid of the human interference as far as possible, and thus it can prevent the emergence of the human errors, to ensure fairness and justice of the tests. This issue is analyzed and discussed in the following.展开更多
The Global Navigation Satellite System Reflectometry(GNSS-R) has been proven to be a powerful technique for retrieving geophysical parameters of ocean and land. Airborne GNSS-R is an important experimental platform, b...The Global Navigation Satellite System Reflectometry(GNSS-R) has been proven to be a powerful technique for retrieving geophysical parameters of ocean and land. Airborne GNSS-R is an important experimental platform, because it is not only needed as validation for spaceborne application, but also possesses the advantages to be capable of remote sensing of small and medium scale targets, such as rivers and lakes. This paper presents an overview of China's airborne GNSS-R campaign conducted on May 30, 2014, in Henan. The campaign has two objectives, i.e.:(1) to examine the capability of a GNSS-R payload developed by National Space Science Center,Chinese Academy of Sciences(NSSC, CAS) for airborneobservations and(2) to study the algorithms for soil moisture and river remote sensing, including altimetry and flow velocity measurement. A previous paper has presented results of soil moisture retrieval as part I, and in this paper,initial results of the Yellow River remote sensing are presented as part II. This paper presents the river altimetry results and explores a new potential application of GNSS-R technology, which is used to detect the flow velocity of the river. The river surface height results observed by code delay altimetry method were consistent with the height results of GPS dual-frequency differential positioning altimetry. The GNSS-R altimetry results showed that decimeter level heights were achieved in 1-min sliding average. Comparing with in situ measurements, the GNSSR flow velocity result was reasonable; the error was about0.027 m/s, which indicated the validity and feasibility of using GNSS-R technique to detect river flow velocity.展开更多
文摘Compared with the traditional examinations, the paperless examination of the computer elementary course can not only realize the assessment of the theoretical knowledge, but also can carry out the assessment of the actual operations of some of the operational computer subjects, which can make it more comprehensive. Through the computer evaluation, we can make the results consistent, and get rid of the human interference as far as possible, and thus it can prevent the emergence of the human errors, to ensure fairness and justice of the tests. This issue is analyzed and discussed in the following.
基金supported by the National Youth Natural Science Foundations of China(41405040 and 41405039)the Scientific Research and Equipment Development Project of Chinese Academy of Sciences(YZ201129)the 12th Five-Year Plan of Civil Aerospace Technology Advanced Research Projects(Y1K0030044)
文摘The Global Navigation Satellite System Reflectometry(GNSS-R) has been proven to be a powerful technique for retrieving geophysical parameters of ocean and land. Airborne GNSS-R is an important experimental platform, because it is not only needed as validation for spaceborne application, but also possesses the advantages to be capable of remote sensing of small and medium scale targets, such as rivers and lakes. This paper presents an overview of China's airborne GNSS-R campaign conducted on May 30, 2014, in Henan. The campaign has two objectives, i.e.:(1) to examine the capability of a GNSS-R payload developed by National Space Science Center,Chinese Academy of Sciences(NSSC, CAS) for airborneobservations and(2) to study the algorithms for soil moisture and river remote sensing, including altimetry and flow velocity measurement. A previous paper has presented results of soil moisture retrieval as part I, and in this paper,initial results of the Yellow River remote sensing are presented as part II. This paper presents the river altimetry results and explores a new potential application of GNSS-R technology, which is used to detect the flow velocity of the river. The river surface height results observed by code delay altimetry method were consistent with the height results of GPS dual-frequency differential positioning altimetry. The GNSS-R altimetry results showed that decimeter level heights were achieved in 1-min sliding average. Comparing with in situ measurements, the GNSSR flow velocity result was reasonable; the error was about0.027 m/s, which indicated the validity and feasibility of using GNSS-R technique to detect river flow velocity.
