Traffic Scene Captioning with Multi-Stage Feature Enhancement

Traffic scene captioning technology automatically generates one or more sentences to describe the content of traffic scenes by analyzing the content of the input traffic scene images,ensuring road safety while providing an important decision-making function for sustainable transportation.In order to provide a comprehensive and reasonable description of complex traffic scenes,a traffic scene semantic captioningmodel withmulti-stage feature enhancement is proposed in this paper.In general,the model follows an encoder-decoder structure.First,multilevel granularity visual features are used for feature enhancement during the encoding process,which enables the model to learn more detailed content in the traffic scene image.Second,the scene knowledge graph is applied to the decoding process,and the semantic features provided by the scene knowledge graph are used to enhance the features learned by the decoder again,so that themodel can learn the attributes of objects in the traffic scene and the relationships between objects to generate more reasonable captions.This paper reports extensive experiments on the challenging MS-COCO dataset,evaluated by five standard automatic evaluation metrics,and the results show that the proposed model has improved significantly in all metrics compared with the state-of-the-art methods,especially achieving a score of 129.0 on the CIDEr-D evaluation metric,which also indicates that the proposed model can effectively provide a more reasonable and comprehensive description of the traffic scene.

三江源地区雪豹保护优先区规划

为了将有限资源合理投放到关键区域,实现物种保护成效的最大化,找出质量最好的栖息地及它们之间的迁徙通道是制定保护规划的第一步。本研究以三江源的雪豹(Panthera uncia)栖息地为对象,基于野外调查数据和高分辨率卫星遥感数据,利用物种分布模型、保护规划模型和连通度分析工具,找出了三江源地区雪豹的核心栖息地分布和潜在迁徙通道位置,分析了目前保护中的潜在威胁,并提出了针对三江源西、中、东三块区域的不同保护对策。结果表明:(1)三江源西部核心栖息地比较小而破碎,但迁徙通道较多且没有明显窄点,未来应关注青藏线的潜在阻碍作用,同时应防范道路沿线的野生动物盗猎;(2)中部区域横跨玉树–杂多–囊谦的雪豹栖息地是三江源最大的核心雪豹栖息地,在连通其他种群中也处于中心地位,应通过种群监测确定其健康稳定,对开发、偷猎等威胁防微杜渐,保持其源种群的作用;(3)东部区域人口密度高,受人类活动的影响最大,需保证阿尼玛卿、年保玉则两块核心栖息地的质量,并重点监测甘德县境内的省道处雪豹的迁徙通道是否畅通。三江源地区雪豹栖息地总体质量较好,建议将维持核心源种群的稳定性,保持种群间迁徙通道的畅通作为三江源的雪豹景观保护工作的整体目标。未来应充分利用天地一体化监测手段,开展重要保护物种栖息地状况的评估和预警,尤其是非保护地区域物种核心栖息地的开发建设活动。

Calibration and brightness temperature algorithm of CE-1 Lunar Microwave Sounder (CELMS)

CE-1 Lunar Microwave Sounder (CELMS) is the first passive microwave radiometer in the world to sound the surface of the Moon in the lunar orbit at altitude of 200 km. The scientific objective of CELMS is to obtain global brightness temperature (TB) of the Moon, to retrieve information on lunar regolith, and to evaluate the distribution of helium-3 on the Moon implanted by solar wind. Before launch of CELMS, a series of experiments were carried out in laboratories to test the performances of the systems, and to calibrate the responses between the input of TB and the output of voltage from the receivers. However, the thermal condition exposed to CELMS is more complicated in lunar orbit than on the Earth, which makes the temperatures of different parts of CELMS wave vary greatly, and the cosmic background is not very clean due to the pointing of cold space antenna to the direction of the satellite running, which brings uncertainties into data-processing of CELMS when the temperature of cold space is used as a calibrator. Furthermore, the lack of knowledge on the lunar ingredients and compositions, distributions of physical temperatures, and properties on lunar microwave radiation leads to difficulties in validating the measurements and retrievals of CELMS. By analyzing the results of ground experiments and the measurements of CELMS in-orbit, along with our knowledge of the properties of lunar surface, here we give algorithms on calibration and antenna pattern correction (APC) of CELMS. We also describe in detail the principle of microwave transfer among the elements of CELMS, and discuss the method on testing calibration parameters of the system. In addition, the theory and model on correction antenna pattern of CELMS are developed by comparing antenna temperatures by CELMS with those simulated by microwave radiative transfer models. The global distribution of TB is given and the features of TB are analyzed. Our results show rich information included in TB on the properties of lunar regolith, especially the thickness and dielectric constant, which are nearly directly reflected by the differences of TB at day and those at night.

Distribution and anomaly of microwave emission at Lunar South Pole

Investigation on Lunar polar area is almost every lunar mission’s primary objective in recent years. The rationale behind it is that illumination and ice resources in this area can be potentially very helpful for constructing lunar human base. In this paper, we analyze microwave radiometric characteristics of the Moon by using the newly acquired Chang’E-1 Lunar Microwave Sounder (CELMS) data. Microwave brightness temperature at Lunar South Pole (LSP) is distributed regularly with a style of "ring-in-ring", decreasing from equator to pole. Regolith temperature gradient is bigger at lunar equator than at polar area. Brightness temperature diurnal difference decreases with observation frequency. Microwave brightness temperature distribution maps at LSP and Lunar North Pole (LNP) have been made based on the analysis. It is found that microwave brightness temperature becomes to synchronize with elevation beyond -85° latitude. This phenomenon is related to lightening condition and indicates temperature distribution at LSP. The brightness temperature anomaly cold points are potentially cold trap areas for water or ice while hot points imply plenty of illumination resources there.

Research on microwave radiation features and lunar regolith parameters inversion of the Rümker region

Chang'e-5(CE-5)mission is expected to land and sample in the Rümker region,north of the Oceanus Procellarum.To select optimal sampling points,the microwave radiation features in this mare unit are analyzed,and the dielectric constant and thickness of lunar regolith are retrieved based on Chang'e lunar microwave sounder(CELMS)data.According to the microwave brightness temperature(TB)maps,TB varying with frequency at noon and midnight are different,in which noon TB increases with frequency,but midnight TB does not follow this rule.Moreover,there are differences among TB distributions at the three higher frequencies,especially in the southern part.In addition,a great TB difference between noon and midnight can be seen in Rümker E that shows higher daytime temperature but lower nighttime temperature.The inversion results reveal that the dielectric constant is lower in the west and north,higher in the middle and east,and the largest value occurs in Rümker E.As for the regolith thickness,most areas are uniform and no more than 4 m,with the thickest and thinnest regolith appearing in the northwest and Rümker E,no less than 6 m and about 2.5 m,respectively.Considering the safety and operability of landing and sampling,the northwest with thick regolith is recommended,while the Rümker E should be eluded.