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101.
Danielle C. Sattelberger Joyce M. Kleen Aarin-Conrad Allen Richard O. Flamm 《地理信息系统科学与遥感》2017,54(1):1-19
The largest Florida manatee (Trichechus manatus latirostris) aggregation at a natural warm-water site occurs in Kings Bay, Crystal River, FL. In accordance with the Manatee Recovery Plan, manatee protection areas within Kings Bay have been created by the United States Fish and Wildlife Service (USFWS) and the State of Florida including a year-round refuge designation and seven Federal manatee sanctuaries during the winter manatee season (15 November–31 March). Over the last 30 years, an increase in manatee counts has been observed in Kings Bay which has prompted the need to review existing manatee protection measures. Aerial survey data collected between 1983 and 2012 were used to examine the seasonal change in manatee distribution within Kings Bay to assess the effectiveness of current sanctuary sizes and locations. Regression analysis suggested a significant change in manatee abundance among the winter seasons (p < 0.05). The average winter manatee counts increased by 4.81 animals per year over the 30-year period. Spatially explicit maps using geographic information system (GIS) analysis revealed a strong correlation between high manatee density and artesian springs in Kings Bay during the winter seasons. Highest abundances were identified at three locations: King Spring, Three Sisters Springs, and Magnolia Springs, which coincide with preexisting sanctuary designations. Additional coverage is advocated to support the overflow of manatees outside of sanctuary boundaries. As density patterns were not uniform across summer periods, a consideration of additional boat speed regulations is recommended. 相似文献
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利用扩展共线方程实现组合相机单片影像的空中三角测量,通过该方法来提高全景影像的定位精度。由于组合全景相机中各子相机刚性固定,相机间的相对位姿参数可以精确标定,因此利用扩展共线方程模型,可以将组合全景相机的构像单元从单个子相机影像扩展为整个组合相机获取的多张影像。与已有的球模型方法,包括球理想模型和球严密模型方法相比,本文所用的扩展共线方程方法使用各子相机影像像点作为观测值,避免了球模型方法中由各子相机摄影中心不重合导致的球模型投影误差和摄站内重叠区域融合误差。试验结果表明:与球模型方法相比,本文方法无需模型投影和摄站内重叠区域融合等繁琐的处理过程,避免了由其引起的精度损失,保证了空三网稳定性的同时提高了定位精度。 相似文献
104.
THE APPLICATION OF MINIATURE UNMANNED AERIAL VEHICLE IN 25 NOVEMBER 2016 ARKETAO MW6.6 EARTHQUAKE 下载免费PDF全文
FU Bo LI Zhi-qiang CHEN Jie FAN Xi-wei LI Xiao-li LI Tao YAO Yuan LIU Yao-hui 《地震地质》2018,40(3):672-684
In order to complete the field investigation to the 25 November 2016 Arketao MW6.6 earthquake, ultra-low altitude remote-sensing data were obtained from miniature unmanned aerial vehicle. The surface rupture surveying has important significance for earthquake research. This paper selects the macro-epicenter of Arketao as the study area. The pictures were obtained with DJI Phantom 3 professional input into the software, the Digital Elevation Model (DEM), Digital Orthophoto Map (DOM) were acquired based on photogrammetry method using the overlapped optical remote-sensing images of UAV. Using these data, we can identify surface ruptures that have vertical dislocation.
We selected six feature points and drew the elevation profile. In the elevation profile map, we chose smooth part of the surface rupture sides and obtained the trend line. A stable point in the surface rupture was selected and the abscissa of the point was taken into the equation of two straight lines. Then subtracting the results of the two equations, we can get the vertical dislocation of the surface rupture. On this basis, we chose six feature points and determined their vertical dislocation, which are between 4.4cm and 10.4cm. What's more, taking Bulungkou Xiang in Xinjiang Uygur Autonomous Region for example, we speculated some surface ruptures that have vertical dislocation. It can provide a new method for identifying surface rupture in the field.
In addition, we get DEM data of the Bulunkou area where ambient conditions are very poor, by using miniature unmanned aerial vehicle and taking 255 photos. Putting those photos into the EasyUAV software, we got the area digital elevation of 2cm resolution. Comparing these data with RTK data, we summarized some practical problems and solutions in the practical operation and evaluated the accuracy of miniature unmanned aerial vehicle data. The Pearson Correlation Coefficient is 0.996 6. In terms of absolute elevation, the average result of UAV and RTK differs by 156.96m. In terms of relative elevation, the average result of UAV and RTK differs by 9.74m. Compared with the previous test of Pishan County, there is a notable divergence in the results. It shows that the data accuracy will be affected to some extent in the cold weather in high elevations. The specific impact needs further exploration. 相似文献
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LI Pingxiang YU Jie BIAN FulingLI Pingxiang professor State Key Laboratory of Information Engineering in Surveying Mapping Remote Sensing Wuhan University Luoyu Road Wuhan China. 《地球空间信息科学学报》2005,8(1):23-27
1 Extraction of the steep curve mapThe steep curve is defined as connection linefrom zero cross points which are produced fromthe convolution of Laplace ( LOG) filtration toDEM. Firstly, the elevation data from DEM areprocessed with LOG convolution and zero cross.The sampling formula is 2G(i,j) =12πσ6(r2 -2σ2)e-r2/2σ2 (1)where -M≤i≤M,-M≤j≤M,r2=i2+j2; M isthe filtration radius, nearly equaling to 5.1σ2; pre diction errorσis set to 4. Suppose that e[i,j] is asmall … 相似文献
108.
阮于洲 《测绘与空间地理信息》2011,34(4):255-256
关于航空摄影是否是测绘活动,以及测绘部门是否应将航空摄影纳入测绘统一监管的范畴,目前有不同的认识。本文明确了航空摄影是一种重要的测绘活动,从而论述了测绘部门对航空摄影实施统一监管的法律基础。 相似文献
109.
The Slumgullion landslide in the San Juan Mountains of southwestern Colorado has been moving for at least the last few hundred years and has multiple ponds on its surface. We have studied eight ponds during 30 trips to the landslide between July 1998 and July 2007. During each trip, we have made observations on the variability in pond locations and water levels, taken ground‐based photographs to document pond water with respect to moving landslide material and vegetation, conducted Global Positioning System surveys of the elevations of water levels and mapped pond sediments on the landslide surface. Additionally, we have used stereo aerial photographs taken in October 1939, October 1940 and July 2000 to measure topographic profiles of the eight pond locations, as well as a longitudinal profile along the approximate centerline of the landslide, to examine topographic changes over a 60‐ to 61‐year period of time. Results from field observations, analyses of photographs, mapping and measurements indicate that all pond locations have remained spatially stationary for 60–300 years while landslide material moves through these locations. Water levels during the observation period were sensitive to changes in the local, spring‐fed, stream network, and to periodic filling of pond locations by sediment from floods, hyperconcentrated flows, mud flows and debris flows. For pond locations to remain stationary, the locations must mimic depressions along the basal surface of the landslide. The existence of such depressions indicates that the topography of the basal landslide surface is irregular. These results suggest that, for translational landslides that have moved distances larger than the dimensions of the largest basal topographic irregularities (about 200 m at Slumgullion), landslide surface morphology can be used as a guide to the morphology of the basal slip surface. Because basal slip surface morphology can affect landslide stability, kinematic models and stability analyses of translational landslides should attempt to incorporate irregular basal surface topography. Additional implications for moving landslides where basal topography controls surface morphology include the following: dateable sediments or organic material from basal layers of stationary ponds will yield ages that are younger than the date of landslide initiation, and it is probable that other landslide surface features such as faults, streams, springs and sinks are also controlled by basal topography. The longitudinal topographic profile indicated that the upper part of the Slumgullion landslide was depleted at a mean vertical lowering rate of 5.6 cm/yr between 1939 and 2000, while the toe advanced at an average rate of 1.5 m/yr during the same period. Therefore, during this 61‐year period, neither the depletion of material at the head of the landslide nor continued growth of the landslide toe has decreased the overall movement rate of the landslide. Continued depletion of the upper part of the landslide, and growth of the toe, should eventually result in stabilization of the landslide. Published in 2008 by John Wiley & Sons, Ltd. 相似文献
110.
Narushige Shiode 《GeoJournal》2000,52(3):263-269
This paper reports on recent developments in the visualisation of urban landscapes. There is a growing interest in the contstruction
of 3D models of urban and built environment for which a host of digital mapping and rendering techniques are being developed.
This paper extracts some of the cases that we came across during worldwide interviews carried out in March 2000. Building
on this review, we identify the range of data and techniques adopted for the development of 3D contents and how they could
contribute to geographical analysis and planning of urban environment. A particular focus is given on the effectiveness of
GIS and its related methods for their capacity to accommodate the demands for visual representation of urban environment as
well as the basis for analysis and simulation.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献