光电测距仪周期误差分析

光电测距仪周期误差的正弦特性并不明显，对其原因从仪器结构、周期误差检定处理、实例等方面加以剖析，指出现行处理方式的不足，提出运用多次叠加的合理解决方法。     

相位式测距仪周期误差新探

本文论述了相位式测距仪中理论上未曾弄清,因而在实践中或者被忽视,或者被认为无法解决的谐波窜扰引起的周期误差问题和光窜扰引起的周期误差随距离增大的问题,提出了解决办法,并给出了实验结果。     

短程红外测距仪的周期误差分析

本文提出了红外测距仪周期误差起始相位的物理意义，以解释周期误差起始相位不等于零的原因；分析了用平台法测定周期误差时基线所需要的精度，以及周期误差起始相位的漂移和振幅的随机浮动，对测定周期误差振幅和起始相位的影响；用数理统计方法分析了周期误差的观测点数；推导了判别各种周期误差类型的数理统计显著性检验公式，以及周期误差允许值的数理统计检验公式。     

光电测距仪周期误差的模拟计算分析

本文介绍利用计算机对模拟的观测数据进行周期误差计算的情况。试算结果表明,只有计算时使用的周期长度与仪器实有的周期长度相同时,才能得出正确的结果。最后井用实例说明如何用较长的平台进行有效的检验和计算,并提供了计算程序。     

光电测距仪周期误差初相角的研究

分析了测距仪周期误差初相角变化的原因,提出了周期误差理论的新思路,指出了周期误差处理中应注意的问题。     

光电测距仪周期误差初相角的研究

分析了测距仪周期误差初相角变化的原因,提出了周期误差理论的新思路,指出了周期误差处理中应注意的问题。     

光电测距仪周期误差专用检测平台设计方案

一、引言 光电测距仪具有自动化程度高，测距速度快以及精度高等优点，但是如果对仪器使用不当或维护不好．都有可能造成仪器性能发生变化，导致精度降低．同时随着使用期增长电子元件的老化等性能变化，也是造成仪器精度降低的重要原因．为了掌握每台仪器的性能指标，合理使用仪器，测出高质量的成果，     

测距仪周期误差及加常数的同时测定

文章提出的方法近似于平台法,但又有不同,不需要设置专用平台、检测可在室内进行,因此一般的测绘单位都可自己定期对测距仪进行检定,并且由于消除了外界因素的影响,使得检定结果更为可靠。     

测距仪周期误差及加常数的同时测定

文章提出的方法近似于平台法,但又有不同,不需要设置专用平台,检测可在室内进行,因此一般的测绘单位都可自己定期对测距仪进行检定,并且由于消险了外界因素的影响,使得检定结果更为可靠。     

周期误差的精密检定

用双频激光测量系统作为一个高精度和自动化的测量平台，并采用一种严密的解算方法，使周期误差的检定更具有科学性和可靠性。     

红外测距仪常数的室内检定

本文简要地分析了红外测距仪常数的本质特征及种类,提出了用光束接收受限法测试适合于远距离测量改正的周期误差和加常数以及用正常测试综合求解方法确定适合于近距离测量改正的周期误差、加常数和相位不均匀性综合改正。     

ERRORS IN DEPTH DETERMINATION CAUSED BY WAVES IN THROUGH-WATER PHOTOGRAMMETRY

The determination of depths in shallow water from aerial platforms will become increasingly important as exploitation of coastal resources intensifies. Until a theoretical study of the errors in depth which could be reasonably expected from two-media photogrammetry was made by Okamoto in 1982, there was little relevant literature apart from some isolated case studies. This paper examines the magnitude and distribution of errors in depth caused by the presence of waves on the water surface. The effects of random errors of observational measurement, in combination with waves, are assessed. A conclusion is reached that the traditional method of underwater depth calculation should be modified when the scale of the two media photography is greater than 1:4000.     

THE ERRORS IN A RADIAL LINE PLOT OF AIR PHOTOGRAPHS

Abstract

Lieut.-Col. Browne's interesting method of combii1ing radial line plots (“The Application of Transformation Factors to the Adjustment of Air Photographs”, E.S.R., x, 73, 119-130) depends for its success on the basic accuracy of the radial line plots of the individual air photo strips. It therefore poses the very interesting question: What accuracy can we expect in a graphical radial line plot?     

ERRORS IN THE INDICATION OF GEOSYSTEMS FROM REMOTE SENSING IMAGERY

After a general discussion of principles of remote sensing indication and image recognition theory, the particular errors in this process are analyzed individually: errors in data recording; errors in automated image analysis; errors in interpretation of the content of geosystems; errors in the selection of interpretation keys; and finally errors in generalization and the extrapolation of results. The total error in geosystem indication from remote sensing imagery can be determined by an analysis of these particular errors. Translated by Edward Torrey, Alexandria, VA 22308 from: Geografiya i prirodnyye resursy, 1988, No. 4, pp. 98-107.     

ELIMINATION OF ERRORS OF LATITUDE AND REFRACTION IN THE PAIRING OF AZIMUTH OBSERVATIONS

Abstract

In a previous Article (Empire Survey Review, ii, II) I described a simple graphical method for the elimination of latitude error in observations for azimuth. It was pointed out that the ideal method of adjustment of azimuths would be a simultaneous elimination of both latitude and refraction errors and, with that in view, a purely theoretical method of such an adjustment was demonstrated in the last paragraph of the article. It has now occurred to me that a fairly simple mathematical solution is possible.     

ERRORS OF THE PARALLEL-PLATE MICROMETER

Abstract

The last issue (No. 26) of the Review contained an article on “Observing with the Zeiss and Wild Theodolites”, making reference among other matters to the errors of the parallel-plate micrometer. The statement was made that the error was due to the difference in travel between the two plates. This is not strictly correct but could not be better expressed without additional explanation, out of place in an already overlong article.     

ON THE ELIMINATION OF THE ERRORS OF PAIRING AZIMUTH OBSERVATIONS

Abstract

The perfect pairing of east and west observations for azimuth, put briefly, should consist of combinations of simultaneous observations of stars of the same altitude and of the same declination. Needless to say, this is a counsel of perfection, and in practice the surveyor has usually to rely on some sort of an approximation to this ideal. It is only on very rare occasions that the necessary time is available and the atmospheric conditions favourable enough to obtain this perfect harmony of observations. Assuming that the latitude of the azimuth station and the atmospheric refraction are accurately known, the necessity of pairing would not arise, and the grouping of the observations into two sets of east and west stars with a varying discrepancy between the members of the individual pairs would be quite unnecessary. In general one might say, when an azimuth observation is taken, neither the latitude nor the atmospheric refraction is known accurately, and the question arises as to whether there is any simple method of eliminating or reducing these two causes of error.     

THE USE OF AIRBORNE INSTRUMENTS IN THE DETERMINATION OF ABSOLUTE ORIENTATION ELEMENTS

This paper outlines the history of the development of various auxiliary instruments which can help in the determination of the elements of absolute orientation. The recent work of Dr. H. G. Jerie on height precision is summarised and results of tests carried out with air photography linked to auxiliary instrumental data are presented.     

THE SCALE ERRORS OF AIRY'S PROJECTION BY BALANCE OF ERRORS,WITH SPECIAL REFERENCE TO THE BRITISH ISLES

Abstract

THE formula for the projection is based upon the spherical assumption. To calculate it for the spheroid might be very complicated and would not be worth while. The projection is suitable for very large areas as a compromise between the Zenithal Equal-area projection on the one hand and the Zenithal Equidistant or Zenithal Orthomorphic on the other. Its application to an area as small as the British Isles would not serve any useful purpose. An analysis of its errors in the general case reveals some unexpected simplicities. This analysis is given below, followed by its application to the particular case of the British Isles on the ten-mile scale. This is done merely to find out what changes would have occurred if the supposed drawing of that map on Airy's projection had been real.