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Remote sensing monitoring of aquatic vegetation is critical to the water quality evaluation of plateau lakes. To obtain a clear understanding of the water environment status of Dianchi Lake, a GF-5 hyperspectral characteristics-based optimal NDVI approach was employed to quantify the aquatic vegetation cover and analyze water quality. By characteristic bands recognition, the optimal NDVI was obtained; the spatial distribution of aquatic plants and water quality in Dianchi Lake were then analyzed. Results showed the following: (1) For Caohai, the optimal NDVI value was calculated by B86 in the red band range and B151 in the near-infrared band range, which achieve the best spectral response. For Waihai, the respective bands were B86 in the red band range and B99 in the near-infrared band range. (2) We also found significant regional differences in aquatic plants distribution for the study area. Caohai was dominated by aquatic plants and high-quality water areas only occurred in the northern tip. While the situation for Waihai was much optimistic, areas with poor water quality were mainly found in the north and south parts. Water quality also showed a descending trend from the lakeside zone to the lake center. (3) By comparing to previous studies, we concluded that policy interventions and water protection measures carried out by the government during the past years are extremely effective. The optimal NDVI method provides a reliable evaluation and is potentially transferable to other plateau lake areas as a robust approach for the rapid assessment of water quality.

With the continuous advancement of low-altitude UAV (unmanned air vehicle, UAV) technology for the earth observation and its wide popularity, UAV photogrammetry and SfM (Structure from Motion, SfM) methods have received more and more attention as the latest means to obtain true 3D realistic models of the survey area. As the newest means of measuring geomorphological information, UAV low-altitude photogrammetry and SfM methods can quickly obtain a true 3D realistic model of the survey area, and have been applied to a number of research fields. In this paper, the UAV is used to measure the typical local scene of annular landform at the southern edge of Dinosaur Valley in Lufeng, and the high-resolution geomorphological image data of the investigated area are obtained. Combined with the SFM method, a realistic 3D scene model is constructed, and its geomorphological characteristics are discussed and analyzed. The experimental results show that the DSM (digital surface model, DSM) data based on the SFM method can obtain ground points by filtering, diluting, and classifying the data, and the DEM (digital elevation model, DEM) data with a resolution of 0.2m is constructed by using the progressive encrypted triangular mesh method, which can accurately represent the true geomorphological characteristics of the study area. (2) Construction of three typical elevation profiles of the circular scene “inner-middle-outer,” and comparative analysis of the profiles confirmed that the topography of the study area is characterized by the dome ridge line AA' as the main highland ridge line, showing a circular “basin margin” pattern, with gradually decreasing elevations on the inner and outer sides. (3) In order to reveal the complex tectonic geomorphological features of the external scene between the ridge and trough, the ArcGIS surface analysis method was used to extract the ridge lines J1-J7. Accurate quantitative measurements and analysis were carried out to investigate the slope, slope length, slope direction, ridge area face, and other related parameters. (4) Using the multi-view visual interpretation and typical scene analysis of the three-dimensional 3D model, micro-geomorphological features such as the development of washouts in the survey area and the nodal laminar surface of the geological body can be clearly identified. In addition, the coordinates of the geological body’s spatial location and its production, spreading area, square volume, and other rich geological information can be accurately obtained. Through the above experimental study on the detection of 3D scenes of landforms, the advantages of UAV measurement technology and SFM method to construct DSM data and 3D scene models in fine geological structure detection are demonstrated. This will have an important application prospect and practical value for geological survey, monitoring , prevention and control management in mountainous areas .In addition, the fast, low-cost, high-precision, and non-contact measurement mode can provide accurate data basis and technical support for geological structure detection, geological disaster investigation, risk assessment and prevention and control management.

For multiple embedded computers working together, the functional failure resulting from the underlying hardware or system crash will cause a sudden abort of applications. Different types of applications may have security requirements for data isolation and access control. Therefore, we propose a scheme to implement multi-level security domain dynamic management oriented embedded computers based on MILS architecture. Firstly, the scheme builds local security policy items and access control lists according to type, function and security level. After that, security domain of all applications is constructed to achieve the safety purpose that applications can perform migration cross partitions and cross platforms. Our experiments and analysis show that the proposed scheme is feasible and correct.