COMPUTATION OF DISTANCES OF LONG ARCS FOR RADIO PURPOSES

Abstract

In the E.S.R., No. 59, Vol. VIII, of January, 1946, I gave a formula which I had worked out to give a rapid and easy means of computing the lengths of long arcs, up to 1000 kilometres, between two points whose latitude and longitudes are known on a definite figure of the earth.     

COMPUTATION OF LONG ARCS FOR RADIO PURPOSES

Abstract

In the last instalment of this article I showed how, by computing the difference in height between the spheroid and the sphere at the mid-point of the line, the third order term could be obtained and a more accurate correction to the spherical length applied. This allows the formula to be used for the determination of distances and azimuths for lines far exceeding 1,000 kilometres in length.     

POINT TO POINT COMPUTATION OF GEOGRAPHICAL COORDINATES OF LONG LINES

Abstract

The computation of geographical coordinates in a geodetic triangulation is usually carried out using Puissant's method, in which the assumption is made the sphere radius ν (the radius of curvature of the spheroid perpendicular to the meridian) not only touches the spheroid along the whole small circle of latitude ?,but also, since ρ (the radius of curvature in meridian) is very nearly equal to ν it makes such close contact with the spheroid that the lengths of sides and angles of a geodetic triangle may be considered identical on both sphere and spheroid.     

COLOR SYNTHESIS OF MULTISPECTRAL IMAGERY FOR MAPPING PURPOSES

The authors describe common Soviet practice in the making of false-color composite imagery for visual interpretation. Also addressed are standard image interpretation techniques: figure-ground color contrast, color separation (number of color gradations occurring within an average contrast range), and so-called landscape indicator techniques. Related issues, such as selection of spectral bands and filters for specific interpretation tasks, and the changing reflectance characteristics of band-specific intermediate images, receive attention as well. Tables and figures illustrating relationships between photographic contrast, film contrast ratings, optical densities, and spectral bands are included. Translated from: Geodeziya i kartografiya, 1985, No. 4, pp. 41-46.     

A DRAFTING MACHINE FOR CIRCULAR ARCS OF ANY RADIUS

Abstract

1. Theory.—In Figs. 1. a and 1. b the letters R represent in each case four equal links of any length forming a freely jointed rhombus. L, L are two equal links of any length. (n ± 1), n are respectively a fixed and a rotating link whose lengths are in the ratio (n ± 1)/n.     

AVALANCHE-HAZARD MAPS FOR PLANNING PURPOSES

General principles governing a structured, multiscalar approach to avalanche-hazard mapping are outlined. At an initial [regional] stage, intermediate-scale mapping (1:300,000) reveals spatial patterns of relevant avalanche parameters and possible lines of research into avalanche forecasting and control. Mapping at the second [local-planning] and third [site-planning] stages, at scales of 1:100,000 and 1:10,000 respectively, is oriented toward formulation of specific site selection and protection measures, and the development of monitoring and forecasting procedures. Excerpts from representative maps at each level are provided, along with detailed legends. Translated from: Materialy glyatsiologicheskikh issledovaniy, USSR Geophysical Committee Publication No. 51. Moscow: Mezhduvedomstvenniy geofizicheskiy komitet, 1984, pp. 216-223.     

DIRECT USE OF AIR PHOTOS FOR CADASTRAL PURPOSES IN ZANZIBAR

Abstract

Since a number of factors have combined to separate the second part of this paper from the first appearing in the E.S.R., issue No. 63, Volume IX, pp. 1–14, and written by Sir Ernest Dawson, I feel that some emphasis, already given, may reasonably be reproduced. To quote from Sir Ernest's paragraph on the Main Problem :—“The crux of the matter which I had been invited to solve, was the definition and record in a simple, sure and economical way, of the increasing number of unstable small holdings in their tangled setting throughout the Protectorate.”     

DIRECT USE OF AIR PHOTOGRAPHS FOR CADASTRAL PURPOSES IN ZANZIBAR

Abstract

At the end of 1934 I visited Zanzibar at the invitation of the Government to advise on methods of cadastral survey and land registration suited to local conditions. Here I am only concerned with the former aspect of this problem. Although stated in general terms, it was in the tenure of the clove and, to a lesser extent, the coconut holdings that the need for these associated records had primarily appeared. My inquiry led to the submission of proposals for the direct use of vertical air photographs for a dual purpose cadastral survey of the Protectorate, which would not only satisfy the requirements of a Land Register, but also systematically furnish information of value to clove cultivation following earlier recommendations made by Professor R. S. Troup. Space does not permit of consideration of this associated objective here, but the possibilities which the method offers of providing concurrently an agricultural as well as a cadastral record is one of its claims to consideration.     

SOIL-GEOCHEMICAL MAPPING FOR ENVIRONMENTAL PROTECTION PURPOSES

The authors outline a procedure for the mapping of soil geochemical anomalies surrounding a gas condensate deposit in upland East Siberia. An end product is a map showing areas in which matter is biologically cycled in different ways and at different intensities, as reflected in the dominance of different combinations of chemical elements in the soil. The paper explores the relationship between these geochemical regions and (a) related natural regions (vegetation, geomorphologic-geologic) and (b) types of human impact (e.g., fires, oil-gas drilling, pipeline construction). The methods employed are compared with previous methodologies of geochemical mapping—e.g., of Perel'man. Translated by Edward Torrey, Alexandria, VA 22308 from: Geografiya i prirodnyye resursy, 1997, No. 1, pp. 23-33     

COMPILING LAND USE MAPS FOR PLANNING PURPOSES

The author outlines a series of recommendations for the compilation of land-use maps used for regional economic planning, based on experience gained in a portion of southwestern Siberia. These recommendations include: (a) selection of an intermediate scale for mapping, suitable for the portrayal of both moderate detail and broad regional patterns, (b) compilation of a series of related environmental-economic maps on a common base, to facilitate comparisons, and (c) portraying on a final map not only land use per se, but incorporating natural limitations and resulting land improvement measures into ratings of existing and potential productivity. An example of the latter is provided, with the map legend organized according to a matrix format. Incorporation of productivity ratings is believed to reduce subjectivity involved in the formulation of planning recommendations. Translated from: Geografiya i prirodnyye resursy, 1985, No. 2, pp. 92-97.     

一种空气饱和差区域分布的推算方法

以遥感图像反演的地表温度、表观热惯量为自变量,通过遗传规划方法,找到了区域空气饱和差这一非遥感参数的求算方法。     

TEMPERATURE MEASUREMENT AND SURFACE CHAINING FOR CADASTRAL PURPOSES

Abstract

The measurement of the temperature of a measuring band or bar has always been a major problem. A considerable a.mount of experimentation has been done on the morepreciseaspects of survey measurement, and attempts, ranging from packing measuring bars in ice to bimetallic apparatus, made to reduce temperature errors. At the present time electro-resistance thermometers are being used and an entire new field is being investigated using various waves for distance measurement. For at least some time in the future, however, these new techniques will not be sufficiently developed to be of practical or economic use to the cadastral surveyor. Nevertheless very much less interest is taken in what may be termed “bread and butter” procedures.     

THE GEODIMETER: AN INSTRUMENT FOR THE ACCURATE MEASUREMENT OF DISTANCES BY HIGH-FREQUENCY LIGHT VARIATIONS

Abstract

The constant K in equation (12) represents distance expended through time lags in the instrument itself, and, although the value of K can be calculated from electrical data, this would not be very satisfactory and it would be better to determine it directly by means of observations over a line of known length. In addition, the point from which K would be reckoned is not a convenient one for actual field measurements. Instead of this, it is more convenient to choose an index mark on the instrument itself and referall measurements to this and thence to the mark over which the instrument is set up.     

THE GEODIMETER: AN INSTRUMENT FOR THE ACCURATE MEASUREMENT OF DISTANCES BY HIGH-FREQUENCY LIGHT VARIATIONS

Abstract

During the last few years a method of measuring accurately the lengths of lines of moderate length by means of high-frequency variations in the intensity of light emitted by a special transmitter, which promises to have many important applications in triangulation and precise traversing, has been devised by Mr. E. Bergstrand, of the Geographical Survey of Sweden. In principle, the method has certain resemblances to the apparatus invented and used by Fizeau for measuring the velocity of light, Bergstrand's instrument having been designed in the first place for the measurement of the same constant. In Fizeau's apparatus, it will be remembered, a ray of light was directed through the cogs of a revolving toothed wheel towards a distant mirror, and, when the wheel reached a certain angular velocity, the ray reflected from the mirror was intercepted by the cogs, so that an observer stationed on the same side of the wheel as the light source no longer saw the reflection of the light in the mirror. The angular velocity of the wheel being known or observed, the time taken for the cogs to obliterate the reflected image could be calculated, and twice the distance to the mirror divided by this time gave the velocity of light. In the Bergstrand apparatus, which is called the “geodimeter”, light pulses of known frequency and varying intensity are directed to the end station of the line whose distance is required, and, after reflection by a mirror at that station, are received back in a special receiving apparatus alongside the transmitter. Here they are converted into small electric currents, which, when the required distance is a certain function of the wave length of the transmitted and reflected pulses, can be made to give zero deflection on a sensitive galvanometer. In this way, the distance to be measured can be determined in terms of the wave length of the pulses. Experiments so far carried out with this apparatus have been successful up to distances of about 36 kilometres. Even with the latest model, however, as we shall see later, it is necessary to know the approximate distance to within 1½ km.     

卫星遥感数据景的地理坐标工程计算

在卫星遥感数据预处理中,图像地理坐标是基于卫星观测视线向量的变换和景基准点地理坐标的计算而确定的。本文介绍了景基准点地理坐标的计算原理和运行系统工程计算的实现方案。     

多曲线求交的批量解法

本文提出了求解大量曲线交点的一种批量解法，在该算法运行时，将首先应用矢量栅格化方法探测可能相交的曲线和交点的大致位置，然后从这些结果出发经数学运算得到精确的曲线交点，从而减少了曲线求交的计算量。本算法可提高地理信息系统及计算机制图系统中矢量数据求交运算的速度，从而增强它们的数据处理能力。     

GRAPHICAL COMPUTATION OF SPHERICAL EXCESS

Abstract

In the reduction of geodetic triangulation the computation of the spherical excess of each triangle is of great importance; for unless the amount of spherical excess is known, the accuracy with which the angles have been observed cannot be assessed, nor can the triangle itself be computed by the simple formulae applicable to plane triangles.