PROMOTIONAL IMAGERY OF GLACIER NATIONAL PARK*

ABSTRACT. The Great Northern Railway vigorously encouraged visitation to Glacier National Park between 1911 and 1930. We reconstruct the railway's promotional imagery of Glacier through an assessment of 796 photographs used by the company to publicize park landscapes and activities. Seven themes in the photographs—Native Americans, scenery, recreation, wildlife, the Wild West, park management, and personalities—reveal a useful portrait of how Glacier National Park was marketed with images of the American West mass distributed for decades by one of the nation's most influential corporations.     

应用 TMS 32010 实现微机遥感图像快速处理

本文主要介绍一种利用TMS 32010数字信号处理器(DSP)和IBM-PC/XT微机构成的微机遥感图像快速处理系统。在此系统上,我们根据微波遥感图像的特点,采用TMS32010宏汇编语言研制出了一个遥感图像快速处理软件库。经过机载微波辐射计图像处理检验,采用TMS 32010语言编程在该系统上的图像处理速度要比采用FORTRAN语言编程在普通微机系统上的图像处理速度提高了100-500倍。此外,本文还提出一种新的平滑滤波算法。该算法滤除高斯白噪声的能力要优于中值滤波,同时还可以保护图像的边缘不被模糊。     

A comparative study of the segmentation of weighted aggregation and multiresolution segmentation

Multiresolution segmentation (MRS) algorithm has been widely used to handle very-high-resolution (VHR) remote sensing images in the past decades. Unfortunately, segmentation quality is limited by the dependency of parameter selection on users’ experience and diverse images. Contrarily, the segmentation by weighted aggregation (SWA) can partly overcome the above limitations and produce an optimal segmentation for maximizing the homogeneity within segments and the heterogeneity across segments. However, SWA is solely tested and justified with digital photos in computer vision field instead of VHR images. This study aims at evaluating SWA performance on VHR imagery. First, multiscale spectral, shape, and texture features are defined to measure homogeneity of image objects for segmentation. Second, SWA is implemented to handle QuickBird, unmanned aerial vehicle (UAV), and GF-1 VHR images and further compared with MRS in eCognition software to demonstrate the applicability of SWA to diverse images in building, vegetation and water, forest stands, farmland, and mountain areas. Third, the results are fully evaluated with quantitative measurements on segmented objects and classification-based accuracy assessment on geographic information system vector data. The results indicate that SWA can produce higher quality segmentations, need fewer parameters and manual interventions, create fewer segmentation levels, incorporate more features, and obtain larger classification accuracy than MRS.     

基于多光谱影像和DEM的泥石流堆积扇识别研究——以白龙江流域武都段为例

选取中国泥石流多发区白龙江流域武都段作为研究区,在对该区域泥石流堆积扇的形态特征和堆积范围进行实地调绘的基础上,利用高分辨率影像(SPOT)进行目视解译,获得研究区部分泥石流堆积扇和非泥石流堆积区的分布范围,将其作为已知样本区。利用该区域多光谱遥感影像(ASTER)和数字高程模型(DEM),提取包含波段比和主分量的几十种特征指标。通过运用方差分析和聚类分析等方法对各指标进行分析计算,选取对区别泥石流堆积扇最具显著意义的指标进行输入,进而采用基于像元的分类方法识别泥石流堆积扇。得到如下结论:SPOT与ASTER融合影像的波段比、主分量指标可以有效地突出土壤岩石中的矿物成分,对泥石流堆积扇的识别具有显著意义;利用筛选出的遥感指标和地形指标作为输入,进行监督分类识别泥石流堆积扇,能够有效地将遥感指标和地形指标相结合,提取的堆积扇覆盖范围与实际情况较为接近。     

基于像素工厂的地理国情普查标准时点核准DOM生产关键技术研究

针对第一次全国地理国情普查标准时点核准对影像数据的需求,本文对利用像素工厂软件进行正射影像制作的关键技术进行了研究,总结像素工厂软件的优势,为卫星影像数据制作数字正射影像提供指导。     

Horizontal accuracy assessment of very high resolution Google Earth images in the city of Rome,Italy

Google Earth (GE) has recently become the focus of increasing interest and popularity among available online virtual globes used in scientific research projects, due to the free and easily accessed satellite imagery provided with global coverage. Nevertheless, the uses of this service raises several research questions on the quality and uncertainty of spatial data (e.g. positional accuracy, precision, consistency), with implications for potential uses like data collection and validation. This paper aims to analyze the horizontal accuracy of very high resolution (VHR) GE images in the city of Rome (Italy) for the years 2007, 2011, and 2013. The evaluation was conducted by using both Global Positioning System ground truth data and cadastral photogrammetric vertex as independent check points. The validation process includes the comparison of histograms, graph plots, tests of normality, azimuthal direction errors, and the calculation of standard statistical parameters. The results show that GE VHR imageries of Rome have an overall positional accuracy close to 1 m, sufficient for deriving ground truth samples, measurements, and large-scale planimetric maps.     

基于控制点影像数据库的国产卫星影像纠正技术研究

随着国产卫星影像的广泛应用,其影像高效率、高精度的处理变得越来越重要。本文基于控制点和影像数据建立福建省控制点影像数据库,并采用相关系数法进行影像匹配,实现影像控制点的自动提取。结果表明,利用控制点影像数据库进行影像的几何纠正具有较高的精度,可提高生产效率,具有实用性。     

基于DMSP/OLS与NDVI的江苏省碳排放空间分布模拟

结合江苏省经济结构和自然环境情况,选择合适的碳排放模型进行核算,得到江苏省各区县的碳排放量,综合DMSP/OLS夜间灯光影像和NDVI数据,再结合人口、GDP和工业生产总值数据,构建碳排放的空间滞后回归模型并开展江苏省碳排放的空间分布模拟,得到大小为1km×1km的碳排放空间格网,并对模拟结果纠正,用以研究江苏省各区县的碳排放量分布情况。结果表明,江苏省碳排放清晰地呈现出"苏南苏北苏中"的格局,苏南地区分布着以苏州、无锡为中心和以南京市区为中心的碳排放高值集聚的"热点"区域;在各区县内部,碳排放的空间分布与人口、GDP产值等密切相关,明显集中于人口、工业聚集的市区和县城区域。     

IP-S2车载移动测量系统在数字城管信息系统中的应用

主要介绍了IP-S2车载移动测量系统的构成及系统特征,通过对系统工作流程和技术路线的详细说明,结合采集的数据特点阐明了系统可以实现的功能。该系统应用于数字城管信息系统中,实现了多种辅助分析功能,为城市的智能化管理和地理信息数据的获取和应用提供了一种快速多样的应用途径。     

Along-Channel Winds in Howe Sound: Climatological Analysis and Case Studies

This paper examines along-channel winds within Howe Sound, British Columbia, Canada, that occur from both the interior plateau out toward the coast as outflows and from the coast inland as inflows. First, the relationships between along-channel winds and pressure, temperature, and humidity are explored in Howe Sound–Cheakamus Valley. The pressure gradients between Pam Rocks and Squamish and Pam Rocks and Pemberton have the strongest correlations with outflow strength and that between Pam Rocks and Squamish has the strongest correlation with inflow strength. Outflows (inflows) have lower (higher) temperatures and dew point temperatures, except for the inflows in summer, which have lower dewpoint temperatures than the overall mean. Second, two case studies of outflow events are presented and described during the period of intensive observations prior to and during the Vancouver 2010 Winter Olympics. The January 2010 outflow event is caused by a zone of strong across-barrier mean sea level pressure gradient. The pressure gradient is formed behind an Arctic front that moved southward across Howe Sound. The February 2010 outflow event is caused by an approaching sea level low pressure centre from the Pacific that formed a northeast–southwest mean sea level pressure gradient across southern British Columbia. In the January case, the outflow layer is about 1.5?km deep, while it is shallower in the February case. Only the January outflow case exhibits hydraulic behaviour.