激光测距森林罗盘仪简介

《DQS-1型激光测距森林罗盘仪》首次将激光技术应用于森林测量,具有可见光导向、直接测距和坡面读水平距三项基本功能,是现行森林罗盘仪的换代产品。该仪的主要特点是: 1.利用氦氖激光的红色可见光指示测线方向,使作业人员由被动状态变成有目的的主动作业。砍线员接照红色光斑的指示砍伐测线,既避免了无效劳动,又减少了不必要     

袖珍计算机在罗盘仪测量内业上的应用

在林业生产上,经常使用罗盘仪进行小区域面积测量。为了提高罗盘仪测量内业成图、求积的速度及精度,研究利用SHARPPC—1500袖珍计算机编制了罗盘仪闭合导线测量的内业程序,经过在森林经营作业设计和伐区检查生产实践中应用,完成一个测     

DQL-1型测树罗盘仪的设计与应用

<正> DQL-1型测树罗盘仪是多种功能林业仪器,它兼有精密测树仪、森林罗盘仪和低精度经纬仪的功能,除用于林分因子调查、树种选优和林地勘测外,也适用于农田、牧场、工程、地质和测绘等部门的一般精度测量。该仪     

森林资源三类调查中几种面积测量方式的应用比较

在森林资源三类调查工作中,多年来一直以森林罗盘仪作为主要的测量仪器,至今在河北省的森林经营规程中还是规定面积测量需要使用罗盘仪。随着卫星定位技术的不断完善,GPS手持机测量技术日趋成熟,国家林业局在2012年8月发布的《森林抚育作业设计规定》中,首次明确了可以用GPS手持机进行面积测量,通过对木兰围场国有林场管理局在实际工作中采用罗盘仪和GPS手持机两种测量方式同步测量获得的数据进行比较分析,GPS手持机全面取代罗盘仪进行三类调查的面积测量是可行的。     

DQL—1型测树罗盘仪的设计与应用

一、前言 DQL—1型测树罗盘仪是多功能林业仪器,它兼有精密测树仪、森林罗盘仪和低精度经纬仪的功能,除用于林分因子测量、树种选优和林地勘测外,也适用于农田、牧场、工程、地质和测绘等部门的一般精度的测量。本仪器于一九八一年十二月通过技术鉴定,已由江苏省南通光学仪器厂投产。     

SC—16型森林综合勘测仪研制成功

<正> SC—16型森林综合勘测仪是一种测量、测树兼用的多功能、多用途综合性的光学测量仪器,它综合了罗盘仪、经纬仪、水平仪、测树仪等多种仪器的主要功能设计而成。该仪器除了能做一般距离,水平角、方向角、坡度、高差等地面测量外,在森林资源调查中还可以应用它测定各项     

DQS-1A无标尺森林罗盘仪在测树及林业生产上应用效果的试验

1 概述DQS～1A森林罗盘仪是一种新型多功能林业测量精密仪器。它不但可完成普通罗盘的一般林业测量,还可以量测可见树干任意部位的直径、树木的测高、立木材积测定和材种出材量调查等,其仪器的最大特点是无标尺测距、测高和测径,对育种工作的树种选优,固定样地的定位测量有很大的优越条件,能解决树木上部直径测量的困难,能准确、迅速得出结果。     

利用罗盘仪测设林道

林道的勘测设计,一般采用水准仪测量。但在基层林场,既没有水准仪器,又缺乏水准测量技术,致使林道的勘测感到困难。在生产实践中,我们摸索和总结了利用罗盘仪勘测设计林道的方法,它具有简单方便准确实用等优点。凡有罗盘仪的林场都能采用这种方法测设林道。只要测量一次就可完成林道的导线测量和纵断面测量。精确度一般可达到水准测量的要求。一、踏查:在勘测林道前,首先对要修林道的地段进行一次全面的踏查。主要察看地形地貌,林道如何安排,可能延伸到什么地方,有一个大略的估计,并初步确定测设的措施和方法。二、选线定点:这是林道测设中的关键一环,林道特别是支叉林道都具有地形复     

新型森林測量工具——激光测距森林罗盘仪

一种国内外首创,将激光技术应用于森林测量的新型测量仪器—激光测距罗盘仪,由吉林省林业科学研究所和北京大学物理系研制成功。该仪将森林测量中的导向、测距和斜距换算水平距三项工作结合在一起,创造了一仪多用的功效。可以提高工作效率,降低劳动强度,提高测量精度,减少森林调查中林木损伤,是现行森林罗盘仪的换代     

智能森林罗盘仪在森林资源一类清查中的应用研究

森林罗盘仪已经不能适应林业调查技术现代化的需要。我们对智能森林罗盘仪与森林罗盘仪在一类调查中的应用进行了对比研究。结果表明:智能森林罗盘仪达到了一类调查精度要求;其精度、效率都要高于森林罗盘仪,工作强度明显降低;在一类调查中可以取代森林罗盘仪。     

洱源县山区典型地带不同利用类型土壤养分的时空动态变化

利用IN—SITU技术,以洱源县山区典型地带保存较好的旱冬瓜阔叶林为参照,选择自然植被破坏后形成的坡耕地、针叶林地、针阔混交林地、按树林地等不同利用类型土壤性质变化的样地进行长期定位研究,测定土壤有机质、全氮、水解氮、速效磷、速效钾．研究其水平空间变化、垂直空间变化及季节动态变化规律．     

洱源县山区典型地带不同利用类型土壤养分的时空动态变化

利用IN-SITU技术,以洱源县山区典型地带保存较好的旱冬瓜阔叶林为参照,选择自然植被破坏后形成的坡耕地、针叶林地、针阔混交林地、桉树林地等不同利用类型土壤性质变化的样地进行长期定位研究,测定土壤有机质、全氮、水解氮、速效磷、速效钾.研究其水平空间变化、垂直空间变化及季节动态变化规律.     

Applying airborne LiDAR for forested road geomatics

Airborne Light Detection and Ranging (LiDAR) has become a popular remote sensing technology to create digital terrain models and provide forest inventory information. However, little research has been done to investigate the accuracy of using scanning airborne LiDAR to perform road geomatics tasks common to forest engineering. We used airborne LiDAR to estimate existing forest road characteristics in support of a road assessment under four different canopy conditions. In estimating existing road centerlines, LiDAR data had a vertical root mean squared error (RMSE) of 0.28 m and a horizontal RMSE of 1.21 m. Road grades were estimated to within 1% slope of the value sampled in the field and horizontal curve radii were estimated with an average absolute error of 3.17 m. The results suggest that airborne LiDAR is an acceptable data source to estimate forest road centerlines and grades, but some caution should be used in estimating horizontal curve radii, particularly on sharp curves.     

Application of an airborne laser scanner to forest road design with accurate earthwork volumes

In this study we developed a forest road design program based on a high-resolution digital elevation model (DEM) from a light detection and ranging (LIDAR) system. After a designer has located the intersection points on a horizontal plane, the model first generates the horizontal alignment and the ground profile. The model precisely generates cross-sections and accurately calculates earthwork volumes using a high-resolution DEM. The model then optimizes the vertical alignment based on construction and maintenance costs using a heuristic technique known as tabu search. As the distance between cross-sections affects the accuracy of earthwork volume calculations, the results were examined by comparing them with the exact earthwork volume calculated by the probabilistic Monte Carlo simulation method. The earthwork volumes calculated by the Pappus-based method were similar to those calculated by the Monte Carlo simulation when the distance between cross-sections was within 10m. The model was applied to a high-resolution DEM from the LIDAR of Capitol Forest in Washington State, USA. The model generated a horizontal alignment, length 827m, composed of five horizontal curves. We examined the number of grade change points. The results indicated that tabu search found the best solution ($61.42/m) with five grade change points. This was composed of two vertical curves that almost followed the ground profile. As the accuracy of a high-resolution DEM from LIDAR increases, the model would become a useful tool for a forest road designer because it eliminates or at least reduces the time-consuming process of road surveys.     

Development of Digital Multi-function Dendrometer

The development of high-resolution remote sensing imaging technology provides a new way to the large-scale estimation of forest canopy density. The traditional inversion methods for canopy density only use spectral or topographical features of remote sensing images.However,due to the existence of the different thing with same spectrum and the same thing with different spectrum phenomena,it is difficult to improve the estimation accuracy of canopy density.Based on spectrum and other traditional features,this paper combines texture features of remote sensing images to estimate canopy density.Firstly,the gray level co-occurrence matrix (GLCM) texture features are computed using objectbased method.Then,the principal component analysis (PCA) method is applied in correlation analysis and dimension reduction of texture features.Finally, spectrum and topographical features together with texture features are introduced into stepwise regression model to estimate canopy density.The experimental results showed that compared with the traditional method only based on spectrum or topographical features,the method combined with texture features greatly improved the estimation accuracy.The coefficient of determination(adjusted R~2 ) increased from 0.737 to 0.805.The estimation accuracy increased from 81.03%to 84.32%.     

目标群落、景观格局与"距离"——森林活力评价的新视角

森林不但是一种水平格局上的镶嵌景观,且其内部群落具有一定垂直结构.传统的森林活力或生态评价只注重其中一方面.选择"目标群落"作为参照基准计算与被评估群落"距离"的思想,为建立跨尺度、多要素的森林活力评价方法提供了契机.文章以石林世界公园的4种森林植被类型为研究对象,遵循"目标群落""距离"评价思想,建立了群落和景观尺度上的评价项目及其对应的计算指标,并结合两个尺度上的计算指标进行评价.     

Application of the vibration method with additional mass to timber guardrail beams

This study examined whether or not weight, density, and Young’s modulus can be accurately measured by vibration test without weighing beams for timber guardrails. Bending vibration tests with and without the concentrated mass were performed on small clear round bars without the pith of spruce and cedar and on actual size round bars with the pith of cedar for the timber guardrail. The following results were obtained. The vibration method with additional mass could be applied to the round bar as well as the rectangular bar. It is possible that resonance frequency was decreased by the sawn split in the horizontal tapping. It is believed that the free ends condition is easier to realize than the fixed ends condition for cross beams for timber guardrails. The weight of the cross beam for the timber guardrail could be accurately estimated by the vibration method with additional mass under several testing conditions.     

地形对大光斑激光雷达森林回波影响研究

利用三维激光雷达森林回波波形模型模拟了地形对波形的影响,并用ICEsat GLAS的数据对模拟结果进行了验证.结果表明坡度对大光斑激光雷达波形影响较大,随着坡度的增大,地面回波和树冠回波都展宽,波形长度也随之增加,同时地面的波峰和植被的波峰值都降低,来自地面的回波明显减少,并逐渐与靠近地面的回波发生信息混叠.鉴于二者的关系呈近似线性正相关,在实际的森林参数反演中可望通过减去一个含有坡度或地形起伏度的因子进行地形效应纠正.     

林木生长与养分动态模型研究Ⅲ.生长方程的假设与前提

结合实例对吴和胡提出的杉木直径、高和蓄积生长方程的基本假设和边界条件进行了详细的说明和论证,并在直径和高生长方程的基础上给出了杉木径高比系数的动态方程．径高比系数随树龄增长而递减的规律表明杉木直径和高的生长速率递减存在不同步现象,产生这一现象的主要原因是林木生长的平面限制效应大于高度限制效应,因此,森林蓄积增长的主要限制因子是树木的直径生长速率．     

林区公路混凝土梁桥实测挠度限值的探讨

为正确评价林区现有桥梁的技术状态，本文论述了林区钢筋混凝土及预应力混凝土简支梁桥理论计算挠度限值与实测挠度限值的不同．并在分析荷载试验资料的基础上，参照铁路部门的规定，提出了林区钢筋混凝土简支梁桥在使用荷载作用下的实测挠度限值为跨径的１／３０００、预应力混凝土简支梁桥为跨径的１／１６００，该限值可作为荷载试验评定桥梁质量时的刚度指标。