Applied Mechanics and Materials Vols. 303-306

Abstract: Dissolved oxygen (DO) is an important index of water environmental monitoring, to which accurate and rapid determination is of great significance. The automatic DO measurement device, which was launched by Core Company, is able to fast and batch determinate dissolved oxygen in water. Based on this advantage, this study further evaluated the performance of the dissolved oxygen meter as well as analyzed the precision and accuracy of dissolved oxygen determination in different water bodies using mathematical statistics method. The results show that the automatic DO measurement device completely meets the requirements of the national DO automatic analyzer. The instrumental measurement results show high precision and accuracy in different water bodies in addition to the industrial waste water and they keep in line with the traditional iodometry determination results. Experiments of parallel determination of pure water of saturation dissolved oxygen make clear that the determination values of the four electrodes of the apparatus have no significant difference.

Abstract: In order to set up an evaluation method for the uncertainty in determining dissolved inorganic carbon (DIC) in karst river basin by Non-dispersive Infrared (NDIR) absorption detection technique, the continuous propagation model of uncertainty is used to evaluating the uncertainties from DIC measurement in two typical karst groundwater samples. The main steps are as follows: to fit the calibration curve by means of double-error regression firstly; and then to quantify each uncertainty component in the evaluation process; lastly to obtain the synthetic uncertainty model for DIC determination results. Calculations through experimental results show that: (1) the main sources of measurement uncertainty derive from the sub-uncertainties of calibration solutions, calibration curve fitting and measurements process; (2) the lower the DIC content in groundwater samples, the greater the relative uncertainty of measurement results, and the sub-uncertainty from the fitting of calibration curve gives one major contribution to the total uncertainty.

Abstract: With respect to the principle of Digital Elevation Modeling (DEM), through analyzing on the overall measurement accuracy of an InSAR in DGPS/IMU, the authors have mathematically inferred that the dominant factors for system accuracy are: Baseline Length, Baseline Inclination Angle, Radar Side-looking Angle, Phase Difference, the distance from radar antenna to various ground target points, Positioning Coordinate and Velocity of the flying platform, Center Doppler Estimation and such on, put forth a set of delicate formula for the factors on system measurement accuracy and error, verified the aforementioned outcomes by a variety of digital simulations, and thus established the principle in system design for air-borne InSAR system. Therefore, this paper is consequential for surveying and mapping both in theory and engineering.

Abstract: To diagnose and analyze the Penglai 19-3 oil spill incident which occurred in Bohai Sea on 4 June, 2011, MODIS 1B images was used in this article. And histogram equalization enhancement was processed on the image after ratio operation between oil-water sensitive channel bands to emphasize the difference between film and background water’s spectral reflectance, and strengthen the oil spills boundary. And last, we use threshold determination method based on image segmentation, combined with the spectrum characteristic of crude oil, to extract oil spills information from the suspected oil films area. Putting together, we locate the oil spills and estimate the area and quantity of oil films.

Abstract: With the rapid development of modern science and technology, remote sensing geological survey theory based on what is built on the interaction mechanism the physics of electromagnetic radiation and geological body. It is through the multi-wave spectrum (light), more than reality, multi-imaging, multi-polarization, multi-level enhancement processing technical means to collect and analyze remote sensing data in order to get more spectral, space geological information than alteration mapping. Remote sensing geological survey does not require direct contact with the target, but use of visible light, infrared, microwave detection instrument, through photography or scanning mode, the induction of electromagnetic radiation energy, transmission and processing, thereby identifying the surface target from a long-range, high-altitude and even outer space platforms.

Abstract: This paper focuses on the scale correction of coastline extracted from remote sensing images. Measurement of coastline is one of the basic and core work of coastal zone remote sensing monitoring projects. Based on analysis of coastline scale effect and multi-scale simulation of coastline, a scale correction method is presented for remote sensing coastline. This method can be used to correct remote sensing coastline to specified map scale, in order to obtain high-precision remote sensing monitoring results of coastline. The results of application example showed that the absolute error of coastline length is reduced to about one third of the original error after correction using the presented method. So the presented method can increase the accuracy of remote sensing coastline for specified scale substantially.

Abstract: Flood disaster happens frequently in Poyang Lake area, which causes a huge economic loss each year. In order to prevent and reduce the loss caused by flood disaster, and to promote the economic development in Poyang Lake area, the author has researched methods of quick monitoring and evaluating of flood disaster based on RS and GIS. Firstly, the author discusses the technical means of monitoring and assessment of flood disaster, which includes remote monitoring technology and GIS technology. Secondly, taking Poyang Lake area for example, the author introduces the methods and processes of remote sensing monitoring of flood disaster. Finally, various data of damage has been computed rapidly to achieve the purpose of rapid assessment of the loss by using the function of spatial analysis of GIS and withdrawing flooded areas from the remote sensing monitoring image combined with background data.

Abstract: . In the paper, we use med-resolution image data-MODIS to monitor Poyang Lake water surface. The resolution of images is 250 meters. The cycle of the monitoring frequence is 8 days. The monitoring time is from Jan, 1st to June, 25th, 2012. We select water surface in the embankment of Poyang Lake as the research object. The results show that Modis image can extracte water surface information quickly for water monitoring in time. The technology can be supplied to trail the change of Poyang Lake eco-system frequently.

Abstract: Spectral mixture analysis has been widely used in quantifying and monitoring urban land surface composition. Most previous research chose inland cities on flat plains as study areas, masking water before unmixing to acquire acceptable results. As an important type with distinct characteristics, coastal cities should be considered separately. This study took Xiamen as an example of mountainous coastal cities and compared four methods of unmixing using Landsat TM images, before assessing their accuracy through the visual interpretation of a SPOT 5 image. The results show that, for mountainous coastal cities, (1) NSMA (Modified normalized spectral mixture) will lead to spectral confusion between water and impervious surface; (2) Modified NSMA without masking water will lead to spectral confusion between dark mountainous vegetation and impervious surface; (3) Modified NSMA with masking both water and mountainous vegetation achieves better results; and (4) pure pixels of impervious surface and soil chosen from high-resolution images and V through PPI achieve the most accurate unmixing results.

Abstract: Data transmission about ground automatic disaster monitoring system in mine is the key technology link. A method based on data transmission system is proposed, which combined Ethernet technology of wire communication and WiFi technology of wireless communication in mine. The system implements a variety of functions including automatic acquisition of deformation monitoring data, remote real-time transmission, and so on. Through systematic research and practical application on the selection of data communication mode, system structure, key technology and so on, it indicates the system is reliable and maintainable, which provides the technical support for mine's safety and high-efficient production.