抚州市生态系统气象利用价值核算方法

采用抚州市2017—2021年各县（区）气温、降水、日照、风速等气象资料和年鉴统计资料,从气象角度对生态系统的 产品供给利用服务、调节服务和文化服务功能三方面建立生态系统气象利用价值核算方法。结果表明：1）抚州全市生态系 统气象利用价值为233亿元,约为全市年平均GDP 的15.3%。核算指标中,气象供给利用服务价值最高,为219.16亿元,占 总价值的 94.1%;其次为气象文化服务价值,为 12.83 亿元,占总价值的 5.5%。2）抚州市生态系统气象利用价值以临川区 61.16亿元最高,占全市的26.3%;广昌县8.82亿元最少,占全市的3.8%。研究结果可为地方政府和有关部门加强生态保护 规划和推进生态产品价值实现工作提供参考和依据。     

海洋测深综合效应的多测线改正技术

提出了水深测量综合效应的多测线改正技术,通过分析水深测量中的波束角效应、地势效应及载体姿态变化对测深的影响,给出二维数字测深仪的详细设计方法,建立描述水深改正的指标,并用实际地形进行仿真。结果标明,该方法实用性强、改正效果明显。     

SBAS-InSAR形变反演的L曲线谱修正迭代法

提出一种基于L曲线的谱修正迭代法,通过绘制谱修正充分迭代过程中的L曲线,以最大曲率点对应的迭代估值作为最终估计结果.通过SBAS InSAR形变反演实验进行验证分析,结果表明,L曲线谱修正迭代法能够确定残差较小且稳定的估值,提高了谱修正迭代估计结果的精度和稳定性.     

布格改正和地形改正的误差——关于区域重力测量中地形改正最大半径的讨论

在布格改正中,我们假定地壳为无限大水平板。事实上,地球表面是球面而不是平面。当地壳充分小类似于平面时,它不可能同时为无穷大;当地壳充分大时,它又不是一个平面。因此,布格改正势必造成相当大的误差。本文提出几种计算球壳重力的精确公式,用以减少布格改正和地形改正中的计算误差。     

Station threshold bias in short-period amplitude distance and station terms used to compute body-wave magnitudes mb

A cause of bias in estimates of distance and station terms used to compute seismic magnitudes ( m _b) is demonstrated in a comparative study on the world amplitude–distance curve. This bias results from the presence of station thresholds in the measurement and reporting of seismic amplitudes and is analogous to that known to be present in routinely computed magnitudes. Distance terms corresponding to low amplitudes such as in the core shadow will tend to be positively biased as are station terms for stations with high thresholds.     

水准测量大气折射改正公式的严密推导

本文应用积分法对大气折射改正公式进行了严密推导，导出了计算折射改正的严密公式，并给出了简化的实用公式。经过实测检验，该简化公式可以按测段计算折射改正，适用于水准测量，并能达到较好的改正效果。     

Terrain corrections to power 3 in gravimetric geoid determination

In precise geoid determination by Stokes formula, direct and primary and secondary indirect terrain effects are applied for removing and restoring the terrain masses. We use Helmert's second condensation method to derive the sum of these effects, together called the total terrain effect for geoid. We develop the total terrain effect to third power of elevation H in the original Stokes formula, Earth gravity model and modified Stokes formula. It is shown that the original Stokes formula, Earth gravity model and modified Stokes formula all theoretically experience different total terrain effects. Numerical results indicate that the total terrain effect is very significant for moderate topographies and mountainous regions. Absolute global mean values of 5–10 cm can be reached for harmonic expansions of the terrain to degree and order 360. In another experiment, we conclude that the most important part of the total terrain effect is the contribution from the second power of H, while the contribution from the third power term is within 9 cm. Received: 2 September 1996 / Accepted: 4 August 1997     

敦煌壁画计算机存贮与管理信息系统中的图像处理

准确无误的获取和再现洞窟内壁画和佛龛的数字图像是建立敦煌壁画计算机存贮与管理信息系统的关键技术之一。本文讨论了利用计算机技术和摄影测量技术获取壁画的数字图像,并依据近景摄影测量原理和色度学原理对数字图像进行几何纠正和色彩失真矫正的方法,结果表明通过数字图像处理可以达到较高的几何纠正精度和色彩还原效果,为壁画计算机存贮与管理打下基础     

GIS空间数据库系统误差控制的黑箱方法

ＧＩＳ建库数据中系统误差的控制是当前ＧＩＳ数据质量研究领域的重要方向之一。本文提出一种直接估计系统误差综合效应的黑箱方法,而传统的仿射变换将成为该法的特例。文中首先阐述黑箱方法的基本原理,然后根据多元统计学工具建立黑箱校正模型,最后给出模型辨识和参数辨识的具体方法。     

Signal path-curving caused by atmospheric refraction

When a signal propagates in the atmosphere, a small variation will occur in its propagation direction because of refraction. The signal path will be a curve other than a straight-line. The characteristics of signal direction variation in propagation in the atmosphere are detailed, new and more precise path-curving correction formulas are derived on the basis of a new atmospheric layer-built model.