Precise interferometric synthetic aperture radar (InSAR) is a new intelligent photogrammetric technology that uses automatic imaging and processing means. Precise InSAR has become the most efficient satellite surveyin...Precise interferometric synthetic aperture radar (InSAR) is a new intelligent photogrammetric technology that uses automatic imaging and processing means. Precise InSAR has become the most efficient satellite surveying and mapping (SASM) method that uses the interferometric phase to create a global digital elevation model (DEM) with high precision. In this paper, we propose the application of systematic InSAR technologies to SASM. Three key technologies are proposed: calibration technology, data processing technology and post-processing technology. First, we need to calibrate the geometric and interferometric parameters including the azimuth time delay, range time delay, and atmospheric delay, as well as baseline errors. Second, we use the calibrated parameters to create a precise DEM. One of the important procedures in data processing is the determination of phase ambiguities. Finally, we improve the DEM quality through the joint use of the block adjustment method, long and short baseline combination method and descending and ascending data merge method. We use 6 sets of TanDEM-X data covering Shanxi to conduct the experiment. The root mean square error of the final DEM is 5.07 m in the mountainous regions. In addition, the low coherence area is 0.8 km 2. The result meets the China domestic SASM accuracy standard at both the 1∶50 000 and 1∶25 000 measurement scales.展开更多
The influence of the single photon laser altimeter range-gate width on the detection probability and ranging accuracy is discussed and analyzed,according to the LiDAR equation,single photon detection equation and the ...The influence of the single photon laser altimeter range-gate width on the detection probability and ranging accuracy is discussed and analyzed,according to the LiDAR equation,single photon detection equation and the Monte Carlo method to simulate the experiment.The simulated results show that the probability of detection is not affected by the range gate,while the probability of false alarm is relative to the gate width.When the gate width is 100 ns,the ranging accuracy can accord with the requirements of satellite laser altimeter.But when the range gate width exceeds 400 ns,ranging accuracy will decline sharply.The noise ratio will be more as long as the range gate to get larger,so the refined filtering algorithm during the data processing is important to extract the useful photons effectively.In order to ensure repeated observation of the same point for 25 times,we deduce the quantitative relation between the footprint size,footprint,and frequency repetition according to the parameters of ICESat-2.The related conclusions can provide some references for the design and the development of the domestic single photon laser altimetry satellite.展开更多
Block adjustment for satellite images cannot be solved with weak convergence geometric conditions,therefore a plane block adjustment method to improve the targeting precision of images is proposed utilizing DEM as hei...Block adjustment for satellite images cannot be solved with weak convergence geometric conditions,therefore a plane block adjustment method to improve the targeting precision of images is proposed utilizing DEM as height constraint plane block adjustment method.First,a rational function model with affine transformation is selected as the mathematical model of the satellite image plane block adjustment.Second,to update the ground coordinates of tie points(TPs),the plane coordinates of TPs are only solved in the adjustment process.Elevation values are obtained by using DEM interpolation.Finally,the plane coordinates of all TPs and orientation parameters of all satellite images are solved through plane block adjustment with a few ground control points ZY-3 nadir images for two regions are tested for plane block adjustment while ZY-3 forward-nadir-back images of the same two regions are tested for stereo block adjustment.A comparison indicates that almost the same accuracy can be obtained with plane block adjustment support using a 1∶50 000 DEM and stereo block adjustment for ZY-3 images.For ZY-3 nadir images,almost no loss of plane block adjustment accuracy occurred when global DEM with 1 km grid and SRTM with 90 m grid replaced the 1∶50 000 DEM as elevation control,.Test results demonstrate the effectiveness and feasibility of the plane block adjustment method.展开更多
Background： Human Cytomegalovirus（HCMV） infections can be found throughout the body, especially in epithelial tissue. Animal model was established by inoculation of HCMV（strain AD-169） or coinoculation with Hepat...Background： Human Cytomegalovirus（HCMV） infections can be found throughout the body, especially in epithelial tissue. Animal model was established by inoculation of HCMV（strain AD-169） or coinoculation with Hepatitis E virus（HEV） into the ligated sacculus rotundus and vermiform appendix in living rabbits. The specimens were collected from animals sacrificed 1 and a half hours after infection.Results： The virus was found to be capable of reproducing in these specimens through RT-PCR and Western-blot.Severe inflammation damage was found in HCMV-infected tissue. The viral protein could be detected in high amounts in the mucosal epithelium and lamina propria by immunohistochemistry and immunofluorescense.Moreover, there are strong positive signals in lymphocytes, macrophages, and lymphoid follicles. Quantitative statistics indicate that lymphocytes among epithlium cells increased significantly in viral infection groups.Conclusions： The results showed that HCMV or HEV ＋ HCMV can efficiently infect in rabbits by vivo ligated intestine loop inoculation. The present study successfully developed an infective model in vivo rabbit ligated intestinal Loop for HCMV pathogenesis study. This rabbit model can be helpful for understanding modulation of the gut immune system with HCMV infection.展开更多
As the important infrastructures for land mapping and resource monitoring,highresolution remote sensing satellites(HRSS)are urgently demanded for the development of China.In this article,the key technologies of the m...As the important infrastructures for land mapping and resource monitoring,highresolution remote sensing satellites(HRSS)are urgently demanded for the development of China.In this article,the key technologies of the main HRSS are summarized,and these technologies include sensor design,attitude and orbit determination,geometric calibration,imaging model construction,and block adjustment,etc.,which involve the mapping accuracy of HRSS.Finally,the system design of the ZY-3 Satellite(China’s first civil stereoscopic surveying and mapping satellite,to be launched in 2012)is introduced,which mainly include satellite technical specifications and strategies design based on these key technologies research.展开更多
The Austrian node of the Natural Resources Satellite Remote Sensing Cloud Service Platform was established in 2016 through a cooperation agreement between the Land Satellite Remote Sensing Application Center(LASAC),Mi...The Austrian node of the Natural Resources Satellite Remote Sensing Cloud Service Platform was established in 2016 through a cooperation agreement between the Land Satellite Remote Sensing Application Center(LASAC),Ministry of Natural Resources of the Peoples Republic of China and the University of Vienna,Austria.Under this agreement panchromatic and multi-spectral data of the Chinese ZY-3 satellite are pushed to the server at the University of Vienna for use in education and research.So far,nearly 500 GB of data have been uploaded to the server.This technical note briefly introduces the ZY-3 system and illustrates the implementation of the agreement by the first China-Sat Workshop and several case studies.Some of them are already completed,others are still ongoing.They include a geometric accuracy validation of ZY-3 data,an animated visualization of image quick views on a spherical display to demonstrate the time series of the image coverage for Austria and Laos,and the use of ZY-3 data to study the spread of bark beetle in the province of Lower Austria.An accuracy study of DTMs from ZY-3 stereo data,as well as a land cover analysis and comparison of Austria with ZY-3 and other sensors are still ongoing.展开更多
Coccidiosis,an intestinal disease caused by Eimeria protozoan parasites,affects various animal species,and espe-cially poses a significant threat to the poultry industry.The current primary control methods include ant...Coccidiosis,an intestinal disease caused by Eimeria protozoan parasites,affects various animal species,and espe-cially poses a significant threat to the poultry industry.The current primary control methods include anticoccidial drugs and vaccines.However,emerging challenges such as drug resistance and vaccine efficacy issues are rooted in the complex life cycle and species diversification of Eimeria.In this review,we first consolidate recent breakthroughs in understanding Eimeria biology,focusing on the parasite development and its intricate interactions with the host,notably its relationships with host immune cells and the gut microbiota.Furthermore,we provide an extensive sum-mary of current control strategies for Eimeria infections.This includes an in-depth analysis of anticoccidial drugs,their mechanisms of resistance,and the increasing utilization of diverse anticoccidial vaccines to combat these challenges.Finally,we highlight the latest innovative strategies leading the way in coccidiosis control.Through an exploration of cutting-edge techniques,we also provide insights into future directions for effectively combating this disease.In conclusion,the future of coccidiosis control lies in the use of a multifaceted approach,integrating advanced bio-logical insights with innovative therapeutic strategies.This review not only serves to enhance our understanding of Eimeria biology but also provides a valuable resource for researchers involved in developing and implementing strategies to manage and control coccidiosis,ensuring the health and productivity of poultry worldwide.展开更多
文摘Precise interferometric synthetic aperture radar (InSAR) is a new intelligent photogrammetric technology that uses automatic imaging and processing means. Precise InSAR has become the most efficient satellite surveying and mapping (SASM) method that uses the interferometric phase to create a global digital elevation model (DEM) with high precision. In this paper, we propose the application of systematic InSAR technologies to SASM. Three key technologies are proposed: calibration technology, data processing technology and post-processing technology. First, we need to calibrate the geometric and interferometric parameters including the azimuth time delay, range time delay, and atmospheric delay, as well as baseline errors. Second, we use the calibrated parameters to create a precise DEM. One of the important procedures in data processing is the determination of phase ambiguities. Finally, we improve the DEM quality through the joint use of the block adjustment method, long and short baseline combination method and descending and ascending data merge method. We use 6 sets of TanDEM-X data covering Shanxi to conduct the experiment. The root mean square error of the final DEM is 5.07 m in the mountainous regions. In addition, the low coherence area is 0.8 km 2. The result meets the China domestic SASM accuracy standard at both the 1∶50 000 and 1∶25 000 measurement scales.
基金National Natural Science Foundation of China(No.41871382)Open Foundation of the Key Laboratory of Space Active Opto-electronics Technologyand Chinese Academy of Sciences(No.2018-ZDKF-1)。
文摘The influence of the single photon laser altimeter range-gate width on the detection probability and ranging accuracy is discussed and analyzed,according to the LiDAR equation,single photon detection equation and the Monte Carlo method to simulate the experiment.The simulated results show that the probability of detection is not affected by the range gate,while the probability of false alarm is relative to the gate width.When the gate width is 100 ns,the ranging accuracy can accord with the requirements of satellite laser altimeter.But when the range gate width exceeds 400 ns,ranging accuracy will decline sharply.The noise ratio will be more as long as the range gate to get larger,so the refined filtering algorithm during the data processing is important to extract the useful photons effectively.In order to ensure repeated observation of the same point for 25 times,we deduce the quantitative relation between the footprint size,footprint,and frequency repetition according to the parameters of ICESat-2.The related conclusions can provide some references for the design and the development of the domestic single photon laser altimetry satellite.
文摘Block adjustment for satellite images cannot be solved with weak convergence geometric conditions,therefore a plane block adjustment method to improve the targeting precision of images is proposed utilizing DEM as height constraint plane block adjustment method.First,a rational function model with affine transformation is selected as the mathematical model of the satellite image plane block adjustment.Second,to update the ground coordinates of tie points(TPs),the plane coordinates of TPs are only solved in the adjustment process.Elevation values are obtained by using DEM interpolation.Finally,the plane coordinates of all TPs and orientation parameters of all satellite images are solved through plane block adjustment with a few ground control points ZY-3 nadir images for two regions are tested for plane block adjustment while ZY-3 forward-nadir-back images of the same two regions are tested for stereo block adjustment.A comparison indicates that almost the same accuracy can be obtained with plane block adjustment support using a 1∶50 000 DEM and stereo block adjustment for ZY-3 images.For ZY-3 nadir images,almost no loss of plane block adjustment accuracy occurred when global DEM with 1 km grid and SRTM with 90 m grid replaced the 1∶50 000 DEM as elevation control,.Test results demonstrate the effectiveness and feasibility of the plane block adjustment method.
基金supported by the National Natural Science Foundation of China(31272515,31472165,31330076)
文摘Background： Human Cytomegalovirus（HCMV） infections can be found throughout the body, especially in epithelial tissue. Animal model was established by inoculation of HCMV（strain AD-169） or coinoculation with Hepatitis E virus（HEV） into the ligated sacculus rotundus and vermiform appendix in living rabbits. The specimens were collected from animals sacrificed 1 and a half hours after infection.Results： The virus was found to be capable of reproducing in these specimens through RT-PCR and Western-blot.Severe inflammation damage was found in HCMV-infected tissue. The viral protein could be detected in high amounts in the mucosal epithelium and lamina propria by immunohistochemistry and immunofluorescense.Moreover, there are strong positive signals in lymphocytes, macrophages, and lymphoid follicles. Quantitative statistics indicate that lymphocytes among epithlium cells increased significantly in viral infection groups.Conclusions： The results showed that HCMV or HEV ＋ HCMV can efficiently infect in rabbits by vivo ligated intestine loop inoculation. The present study successfully developed an infective model in vivo rabbit ligated intestinal Loop for HCMV pathogenesis study. This rabbit model can be helpful for understanding modulation of the gut immune system with HCMV infection.
文摘As the important infrastructures for land mapping and resource monitoring,highresolution remote sensing satellites(HRSS)are urgently demanded for the development of China.In this article,the key technologies of the main HRSS are summarized,and these technologies include sensor design,attitude and orbit determination,geometric calibration,imaging model construction,and block adjustment,etc.,which involve the mapping accuracy of HRSS.Finally,the system design of the ZY-3 Satellite(China’s first civil stereoscopic surveying and mapping satellite,to be launched in 2012)is introduced,which mainly include satellite technical specifications and strategies design based on these key technologies research.
基金This work was supported by the National Key R&D Program of China for Strategic International Cooperation in Science and Technology Innovation(Grant No.2016YFE0205300)as well as a grant under the Eurasia Pacific UNINET program of the Austrian Federal Ministry of Education,Science and Research to the University of Vienna(Grant No.EPU 32/2017).
文摘The Austrian node of the Natural Resources Satellite Remote Sensing Cloud Service Platform was established in 2016 through a cooperation agreement between the Land Satellite Remote Sensing Application Center(LASAC),Ministry of Natural Resources of the Peoples Republic of China and the University of Vienna,Austria.Under this agreement panchromatic and multi-spectral data of the Chinese ZY-3 satellite are pushed to the server at the University of Vienna for use in education and research.So far,nearly 500 GB of data have been uploaded to the server.This technical note briefly introduces the ZY-3 system and illustrates the implementation of the agreement by the first China-Sat Workshop and several case studies.Some of them are already completed,others are still ongoing.They include a geometric accuracy validation of ZY-3 data,an animated visualization of image quick views on a spherical display to demonstrate the time series of the image coverage for Austria and Laos,and the use of ZY-3 data to study the spread of bark beetle in the province of Lower Austria.An accuracy study of DTMs from ZY-3 stereo data,as well as a land cover analysis and comparison of Austria with ZY-3 and other sensors are still ongoing.
基金supported by the National Natural Science Foundation of China(32302900 and 32373031).
文摘Coccidiosis,an intestinal disease caused by Eimeria protozoan parasites,affects various animal species,and espe-cially poses a significant threat to the poultry industry.The current primary control methods include anticoccidial drugs and vaccines.However,emerging challenges such as drug resistance and vaccine efficacy issues are rooted in the complex life cycle and species diversification of Eimeria.In this review,we first consolidate recent breakthroughs in understanding Eimeria biology,focusing on the parasite development and its intricate interactions with the host,notably its relationships with host immune cells and the gut microbiota.Furthermore,we provide an extensive sum-mary of current control strategies for Eimeria infections.This includes an in-depth analysis of anticoccidial drugs,their mechanisms of resistance,and the increasing utilization of diverse anticoccidial vaccines to combat these challenges.Finally,we highlight the latest innovative strategies leading the way in coccidiosis control.Through an exploration of cutting-edge techniques,we also provide insights into future directions for effectively combating this disease.In conclusion,the future of coccidiosis control lies in the use of a multifaceted approach,integrating advanced bio-logical insights with innovative therapeutic strategies.This review not only serves to enhance our understanding of Eimeria biology but also provides a valuable resource for researchers involved in developing and implementing strategies to manage and control coccidiosis,ensuring the health and productivity of poultry worldwide.
