高分二号异轨立体数据的森林高度提取     

倪文俭  张大凤  汪垚  庞勇  张志玉  刘见礼  何亚婷  郭伟 《遥感学报》2018,22(3):392-399

森林植被碳储量的空间分布格局及其动态变化是陆地生态系统碳收支核算的基础。作为森林地上生物量的重要指示因子,森林高度的精确估算是提高森林植被碳储量估算精度的关键。现有研究已证明,由专业星载摄影测量系统获取的立体观测数据可用于森林高度提取,但光学遥感数据最大的问题是受云雨等天气因素的影响严重。区域森林地上生物量产品的生产需要充分挖掘潜在数据源。国产高分二号卫星(GF-2)虽然不是为获取立体观测数据而设计的专业星载摄影测量系统,但其获取的图像空间分辨率可达0.8 m,且具备±35°的的侧摆能力,在重复观测区域可构成异轨立体观测。本文以分别获取于2015年6月20日和2016年7月19的GF-2数据作为立体像对,其标称轨道侧摆角分别为0.00118°和20.4984°,以激光雷达数据获取的林下地形(DEM)和森林高度(CHM)为参考,对利用GF-2立体观测数据进行森林高度提取进行了研究。通过对立体处理得到的摄影测量点云的栅格化得到DSM,以激光雷达数据提供的DEM作为林下地形,得到了GF-2的CHM。结果表明GF-2提取的CHM与激光雷达CHM空间分布格局较为一致,两者之间存在明显的相关性,像素对像素的线性相关性(R2)达到0.51,均方根误差(RMSE)为3.6 m。研究结果表明,在林下地形已知的情况下,GF-2立体观测数据可用于森林高度估算。  相似文献   

Moon-based Earth observation: scientific concept and potential applications   总被引：2，自引：0，他引：2  

Huadong Guo 《International Journal of Digital Earth》2018,11(6):546-557

Although Earth’s surface parameters obtained from satellite data have become more and more precise, it is still difficult to guarantee temporal consistency and spatial continuity for large-scale geoscience phenomena. Developing new Earth observation platforms is a feasible way to improve the consistency and continuity of such data. As the planet’s only natural satellite, the Moon has special advantages as a platform for observing Earth, including long lifetime, whole disk view, tectonic stability and unique perspective. After presenting the observation geometry constructed by using the ephemeris, this paper mainly discusses the characteristics of a lunar platform and the proper Moon-based sensors, as well as the scientific objectives of Moon-based Earth observation. Solid Earth dynamics, the energy budget of Earth, Earth’s environmental elements and the Earth-space environment are four potential applications analysed in this paper.  相似文献   

The Digital Belt and Road program in support of regional sustainability     

Huadong Guo  Yubao Qiu  Massimo Menenti  Fang Chen  Paul F. Uhlir 《International Journal of Digital Earth》2018,11(7):657-669

The Belt and Road initiative has a significant focus on infrastructure, trade, and economic development across a vast region, and it also provides significant opportunities for sustainable development. The combined pressure of climate variability, intensified use of resources, and the fragility of ecosystems make it very challenging, however, to achieve future sustainability. To develop the path in a sustainable way, it is important to have a comprehensive understanding of these issues across nations and evaluate them in a scientific and well-informed approach. In this context, the Digital Belt and Road (DBAR) program was initiated as an international venture to share expertise, knowledge, technologies, and data to demonstrate the role of Earth observation science and technology and big Earth data applications to support large-scale development. In this paper, we identify pressing challenges, present the research priorities and foci of the DBAR program, and propose solutions where big Earth data can make significant contributions. This paper calls for further joint actions and collaboration to build a digital silk road in support of sustainable development at national, regional and global levels.  相似文献   

藏北高原地区地表辐射出支和能量平衡的季节变化   总被引：15，自引：5，他引：10  

马伟强  马耀明  李茂善  Z.   《冰川冻土》2005,27(5):673-679

对青藏高原地区地表能量的研究是一个十分重要的问题.基于中日合作项目"全球协调加强观测计划之亚澳季风青藏高原试验"(CAMP/Tibet)在2001年8月至2002年9月的观测数据资料,分析研究了青藏高原藏北地区地表能量,即净辐射通量、感热通量、潜热通量和土壤热通量等的变化规律,获得了有关藏北高原地表能量的新认识.  相似文献   

超大城市综合气象观测试验之测风激光雷达数据评估          下载免费PDF全文

张志坚  张静  伍光胜  高瑞泉 《热带气象学报》2022,38(2):253-264

为评估用于超大城市综合气象观测试验的测风激光雷达,从最大有效探测高度和数据获取率两方面对测风激光雷达的探测能力进行分析,同时使用测风激光雷达与深圳气象梯度观测塔的测风资料从不同观测高度、不同观测值等方面进行对比分析,结果表明:测风激光雷达与深圳气象梯度观测塔的风速、风向一致性较好,相关系数分别为0.96、0.99,平均绝对误差分别为0.54 m/s、9.95 °,且不同高度层的测风结果也较为一致,但雨天和雾天条件对测风激光雷达的最大有效探测高度和数据获取率影响较大,设备探测能力受到一定的限制。   相似文献   

非等步长GM(1,1)模型及其在大堤沉降监测的应用   总被引：10，自引：0，他引：10  

刘明波  田林亚  孙和平 《测绘工程》2006,15(3):58-60

针对非等步长数据,传统GM方法是构造等步长序列,生成1-AGO序列,再建立等步长GM(1,1)模型。考虑到变形观测序列非等步长特性,以相邻观测时间间隔为权,直接生成1-WAGO序列,建立非等步长GM(1,1)模型。将GM(1,1)模型应用于堤防工程沉降观测分析与预报,得到了有益的结论。  相似文献   

中国-日本绝对重力仪器测量比对结果   总被引：3，自引：0，他引：3  

孙和平  张为民  王勇  竹本修三  福田洋一 《测绘科学》2006,31(6):33-34,51

本文给出了中科院测地所FG5-112和日本京都大学FG5-201及日本国土地理院FG5-104等几台绝对重力仪在武汉九峰和香港天文台绝对重力测量比对结果。分析说明不同仪器间具有良好的一致性,其中FG5-112与FG5-104结果间的互差达8×10-8m/s2;FG5-112与FG5-201和FG5-104等的观测互差小于2×10-8m/s2。这种比对观测,可为深入了解仪器性能和精确测定不同台站重力非潮汐变化提供可靠参考。  相似文献   

IAP's Solar-Powered Unmanned Surface Vehicle Actively Passes through the Center of typhoon Sinlaku(2020)     

Hongbin CHEN  Jun LI  Wenying HE  Shuqing MA  Yingzhi WEI  Jidong PAN  Yu ZHAO  Xuefen ZHANG  Shuzhen HU 《大气科学进展》2021,38(4):538-545

The solar-powered marine unmanned surface vehicle(USV) developed by the USV team of the Institute of Atmospheric Physics is a rugged, long-duration, and autonomous navigation vessel designed for the collection of longrange, continuous, real-time, meteorological and oceanographic measurements, especially under extreme sea conditions(sea state 6–7). These solar-powered USVs completed a long-term continuous navigation observation test over 26 days.During this time, they coordinated double-USV observations and actively navigated into the path of Typhoon Sinlaku(2020) before collecting data very close to its center during the 2020 USV South China Sea Typhoon Observation Experiment. Detailed high temporal resolution(1 min) real-time observations collected by the USV on the typhoon were used for operational typhoon forecasting and warning for the first time. As a mobile meteorological and oceanographic observation station capable of reliable, automated deployment, data collection, and transmission, such solar-powered USVs can replace traditional observation platforms to provide valuable real-time data for research, forecasting, and early warnings for potential marine meteorological disasters.  相似文献   

Homogenization of the Daily Land Surface Temperature over the Mainland of China from 1960 through 2017     

Dan WANG  Aihui WANG  Xianghui KONG 《大气科学进展》2021,38(11):1811-1822

Land surface temperature(LST) is one of the most important factors in the land-atmosphere interaction process. Raw measured LSTs may contain biases due to instrument replacement, changes in recording procedures, and other non-climatic factors. This study attempts to reduce the above biases in raw daily measurements and achieves a homogenized daily LST dataset over China using 2360 stations from 1960 through 2017. The high-quality land surface air temperature(LSAT)dataset is used to correct the LST warming biases especially evident during cold months in regions north of 40°N due to the replacement of observation instruments around 2004. Subsequently, the Multiple Analysis of Series for Homogenization(MASH) method is adopted to detect and then adjust the daily observed LST records. In total, 3.68 × 103 effective breakpoints in 1.65 × 106 monthly records(about 20%) are detected. A large number of these effective breakpoints are located over large parts of the Sichuan Basin and southern China. After the MASH procedure, LSTs at more than 80% of the breakpoints are adjusted within +/– 0.5°C, and of the remaining breakpoints, only 10% are adjusted over 1.5°C.Compared to the raw LST dataset over the whole domain, the homogenization significantly reduces the mean LST magnitude and its interannual variability as well as its linear trend at most stations. Finally, we perform preliminary analysis upon the homogenized LST and find that the annual mean LST averaged across China shows a significant warming trend [0.22°C(10 yr)–1]. The homogenized LST dataset can be further adapted for a variety of applications(e.g.,model evaluation and extreme event characterization).  相似文献   

基于旋翼无人机的大气边界层环境气象垂直观测及订正方法的研究     

徐家平  赵天良  陈燕  白永清  孙晓芸  王淞  曹畅 《气象与环境学报》2022,38(3):101-111

基于旋翼无人机开展大气边界层观测可为气象要素和大气污染物垂直结构的研究提供具有高时空解析能力的新方法,有助于深入理解低层大气物理化学变化机制。本文详述了旋翼无人机在开展大气边界层环境气象垂直观测实验的应用及优势。基于自主研发的旋翼无人机环境气象观测平台,通过开展传感器在无人机上不同的搭载位置,以及旋翼无人机与探空气球、高塔的对比观测实验,明确了旋翼无人机对气象环境观测的影响及合理的搭载方式。研究进一步在湖北重污染天气条件下开展了0—1000 m的大气边界层垂直观测,并研发了基于旋翼无人机姿态数据的大气边界层气象要素及污染物垂直观测的订正方法。结果表明:实验获取了2—10 m垂直分辨率的高质量大气廓线数据,可精细捕捉大气边界层及其逆温层高度和污染物浓度等要素的垂直变化特征。本文旨在为无人机观测的科研应用提供一种技术可行且数据可靠的观测手段。  相似文献