bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reflections of a European on the Symposium on Land Registration and Data Banks
Authors: Rinner K. 
Published: July 2019

Highlights from the history of surveying and mapping during medieval and modern times in Central Europe are cited to illustrate the ever increasing demand for better surveys and better maps for tax collection, land registration, civil engineering, military, scientific and other purposes. In Austria, which has an area of 75,000 square kilometers and a population of 7,000,000 people, there is complete triangulation, from first to fourth order, and further densification to 500 meters is planned. Control and boundary points are durably marked and described by coordinates. A cadastral resurvey has been completed for some 540 of 5,000 communities. Much of the work has been done by consulting engineers who are obliged to execute public orders during about 30 per cent of their working time. There are about 200 consultants and an equal number of state-employed survey engineers, with a ratio of three technicians per engineer. From a summary of the main features of the new Austrian survey act, some recommendations are made for Canada. Specifically, there should be a network of control points based on a single datum; authorities should issue regulations governing the coordination of all surveys and the recording of all data; accuracy should be related to land value; administration and revision of surveys should be attended to by regional offices and, for large-scale maps and plans, a projection, which permits observed data to be directly related to map data should be chosen. Several related problems, such as the development of a unified datum, are discussed.
A Data Bank for Use in the Social Sciences
Authors: Beaman Jay 
Published: July 2019

A data bank system is important for urban studies. Some of the features that should be included in such a system are mentioned. Urban areas have many social and engineering problems that require much study to understand and solve. A well-organized, flexible data bank system offers the means. All data should be referred to geographic coordinates and, because of the quantity of data, an urban area should be partitioned into relatively small blocks. By use of coordinates, streets, boundaries, etc., can be defined as well as point data. In addition to containing the necessary data, the system must be easy of access. The user must be able to obtain and process data by machine instructions that are easily learned. An example shows how data are called and manipulated to produce a type of map and to compute and tabulate certain statistics. A flexible system is advocated. Limited logic can lead to restrictive studies and thinking. What is desirable at one time and place may not be suitable for another time or another place. Interdisciplinary thinking and the fact that experts disagree must be allowed for.
Data Banks and the Computer Analyst
Authors: Boyle A. R. 
Published: July 2019

The computer analyst is the mainspring in the development of a data bank for automated cartography. To bring this development about, he must cooperate closely with the cartographer and the systems engineer. The computer analyst must consider the bulk of the data and how these data are to be labelled. He must also reflect on how the data bank information is to be used and what manipulative processes it will be subjected to. The analyst will set under way investigations by working groups of cartographers at various levels. These groups will deal in detail with cartographic policy and technical problems hitherto considered only in general terms. When the results of these investigations are known, the analyst will consult the systems engineer to ascertain whether the various specifications can be met. Problems likely to be discussed are the digitizing process, the form of displays necessary and the design of a versatile and accurate “pen’ for the drafting table. Finally, the analyst may have to consider the economics of the system so that he can advise the administrators who will be assessing the overall situation.
The Cadastre as the Basis of an Environmental Data System
Authors: Wallner H. 
Published: July 2019

The function of the present cadastre, a program of cadastre reform and plans for a computer-based public information system in Sweden are presented. In the new cadastre register, approved by the Swedish government in 1968, a uniform notation system for both urban and rural “real estates” will replace the two systems now in use; parcels will continue to be described in a register and on maps; each parcel of land will be represented by one or more points defined by geodetic coordinates and other information, such as land surveyors’ decisions on boundaries, will be included. Digitization of all boundary and property information has started and is scheduled for completion in three to four years. Accuracy to one meter in urban areas and to 10 meters in rural areas is proposed. For the computer-based information system, a large central computer online to display and printout units in regional offices is proposed. By merging computer fies, it will be possible to relate information from diverse registries. For example, in the population register a person will be identified by a census number as living on a real estate identified by a real estate number, which in turn is described by coordinates; hence each person can be associated with coordinates. Extension of this technique offers a flexible and economic solution to information retrieval for community planning, market analyses, transportation optimization and cultural, geographical and historical research.
New Techniques in Mine Orientation Surveys
Authors: Chrzanowski Adam J. 
Published: July 2019

Underground surveys in mines can be oriented either by single-shaft plumbing, double-shaft plumbing with an accompanying connecting traverse, or by gyro-theodolite observations. The relative merits of these methods are discussed. Descriptions are given of two types of laser plummets and of a laser centering detector, which were designed and manufactured at the University of New Brunswick and which facilitate optical shaft plumbing of high precision. Details are presented of surface and underground traverses, connecting mine shafts, in which the distances were measured with the new Wild D1-10 and tellurometer MA-100 infrared instruments. Finally, gyro-orientation methods are outlined. The various errors affecting gyro-azimuth determinations are described in detail and hints are given for ensuring high accuracy.
A Comparative Statistical Study of the Methods of Weighting Observations
Authors: Tiwari R. S. , Rao K. R. B. 
Published: July 2019

The simple arithmetic mean is generally accepted as the most probable value. However, in a set of a small number of observations, a weighted mean is often regarded as being better than the simple arithmetic mean, even if the latter were obtained after rejecting the outlying observations. A number of methods of weighting have been put forward from time to time. This paper presents the result of a statistical study designed to discover whether any of the weighting methods produce values superior to the simple arithmetic mean. The study follows the same lines as a previous paper [Oswal and Tiwari 1965]. Of the six methods compared, only that of Jeffreys has been found to give values statistically superior to the simple arithmetic mean. The use of Jeffreys’ mean is suggested, therefore, for survey work, especially if these values are required for further rigorous adjustment purposes.
Automation in Hydrographic Charting
Authors: Boyle A. R. 
Published: July 2019

This paper provides a general description of the concepts, hardware and programs of the basic system of automatic cartography designed by the University of Saskatchewan for the Canadian Hydrographie Service. The basic system includes an automatic drafting system and a semi-manual digitizing unit. Also described are additions to the basic system which, during the development, have shown themselves to be important and which have been experimentally examined for feasibility. These additions include an interactive display system to be used in computer-aided compilation and in data-base incorporation, an extended digitization system, a visual monitoring system and typed output facility.
Image Deformation and Methods For Its Correction
Authors: Ziemann H. 
Published: July 2019

Image deformation is an error that influences the very base of any photogrammetric operation, the photographic image, and, therefore, its correction is of prime importance. There is no doubt that corrections for image deformation should be applied to the original image rather than at a later stage of the photogrammetric compilation. Image deformation corrections can be carried out most effectively if réseau photography is used. Several kinds of réseau are possible; however, only a réseau projected in central projection and simultaneously exposed with the aerial photograph enables a correction to be made for the effects of insufficient film flattening. This is a more important source of image deformation than film deformation. A number of results are given which prove the superiority of image deformation correction methods that derive, for each point to be corrected, a correction using only the four réseau points surrounding those points, or the réseau point nearest to that point. The effectiveness of these correction methods depends on the density of the réseau.
Precise Traverse in Major Geodetic Networks
Authors: Adler R. K. , Shmutter B. 
Published: July 2019

Investigation of a precise traverse network is presented on the basis of computer simulation of observations. Various aspects affecting the accuracy of final adjusted coordinates are considered, such as the density of Laplace control, the weighting of the various types of observations and the sensitivity of the system to weights. The simulation approach permits the evaluation of results through comparison of adjusted values to an artificially created “errorless” standard. The advantages of a modern precise traverse are considered with a view to its extensive utilization in major geodetic networks.
Rho-Rho Loran-C for Offshore Surveys
Authors: Eaton R. M. , Grant S. T. 
Published: July 2019

Using atomic clocks, the United States Coast Guard has recently pioneered a precise distance measuring version of Loran-C, for positioning by two ranges when within about 1,700 km of the transmitters. In May 1971 the authors took advantage of the calibrated Decca Lambda survey chain, being used by the CSS Baffin on the Grand Banks of Newfoundland, to evaluate the accuracy and reliability of this ‘rho-rho’ Loran-C. This paper outlines briefly the principles of Loran-C and the associated problems of geodesy and radio wave propagation. The procedures for operating rho-rho Loran-C are described and the results of short term (hours) and long-term (weeks) accuracy tests are given. Rho-rho Loran-C is an ‘extrapolative’ navigation system that requires periodic checks at a reference point to adjust accumulated error. It was found that, by taking reasonable precautions, range measuring accuracy of about 200 meters can be maintained over five days or so.
Geodetic Coordinates in Four Dimensions
Authors: Mather R. S. 
Published: July 2019

An attempt is made to summarize arguments for defining geodetic coordinates in the four-dimensional sense, in a manner that will permit their use without undue complexity over extended periods of time for geophysical and geodynamic purposes. Such arguments cannot be isolated from the consideration of techniques for position determination with the highest possible precision for other purposes that are potentially beneficial for the global community, in view of the capital expense involved. The types of observations that offer the most promise in the achievement of these goals are also a factor in the development. A simple system of reference that fulfills the basic requirements of geodetic determinations of this type is described in the context of inter-relations between the geometric and dynamic characteristics of the earth. System requirements for the implementation of such a scheme are outlined. There is disagreement on whether geodesy can contribute any data of significance in the short term, apart from that for studies of gross effects in local regions, toward understanding earthquake mechanisms. However, the overall cost-benefit-oriented geodetic requirements, calling for determinations of the highest precision, appear to warrant the maintenance of a worldwide geodetic network and associated measuring systems in a manner that would also permit the determination of those time variations in geodetic coordinates with global relevance. A historical perspective makes it mandatory that such a scheme be initiated in the next decade, in view of the favorable portents for a significant improvement in the measuring precision.
The Importance of Ordering Systems of Geodetic Normal Equations
Authors: Gergen John G. 
Published: July 2019

An investigation was performed to indicate the importance of ordering systems of normal equations. Two results were obtained: the precision of adjusted positions of 840 points is unaffected by even a casual approach to ordering, and computer time (and cost) can increase significantly if ordering is not performed. The sorting method proposed to achieve ordering is not new, it is very simple, and the cost is negligible. The resulting normal equations are neither minimum band width nor minimum fill-in, but near minimum conditions are obtained in the process.
Canadian National Positional Control Survey Data File
Authors: Porter T. A. 
Published: July 2019

For the past three years the Geodetic Survey of Canada has been developing a computerized storage and retrieval system for geodetic control information. Work has been concentrated on a pilot project to test system concepts. The computerized data file being developed will store coordinates, elevations, observed data, information on adjustments, monumentation, interconnections, identification photography and the text of descriptions. This constitutes virtually all the control survey information requested from the Geodetic Survey of Canada. The data records for each point are stored in geographic order and accessed by an indexed sequential information retrieval system. This scheme permits relatively rapid retrieval of records by location or point number. It is also possible to retrieve by network number, line number or by any other specified parameter in the data record. The output can be printed in several formats and the modular nature of the system allows easy addition of new formats. Retrieved data can also be plotted by specifying the scale, projection and the area covered.
Problems Arising from Redefinition in Densification Surveys
Authors: Chrzanowski Adam , Canellopoulos Nicholas 
Published: July 2019

The redefinition has been considered as a necessary step to improve the primary control network, which at the present does not satisfy the accuracy requirements of all the users. In view of the existing distortions in the primary control and in view of the forthcoming redefinition, the user who is involved in a densification survey faces the following questions: 1) how to perform the adjustment of the secondary networks in order to be independent of the distortion of the primary network, 2) how to take the advantage of those parts of the primary network that satisfy his requirements. If the two questions are answered, one has to solve a problem on how to transform, in the best way, the established secondary network into the redefined coordinates system. The authors try to give an answer to those questions considering the following four cases: 1) the relative accuracy between the higher order points is much better than the relative accuracy of the same points belonging to the densification network; 2) both primary and densification methods have the same accuracy; 3) the relative accuracy of the higher order network is worse than the corresponding of the densification network; 4) the relative accuracy of the points of the higher order network is unknown. The authors advocate that a free adjustment and a fitting method should answer the problem.
Mathematical-Statistical Methods for the Analysis of Aerial Triangulation Adjustment Errors Using a Computer Program
Authors: Allam M. Mosaad 
Published: July 2019

In practice, photogrammetrists use a single statistic reliability interval criterion, based on the mean square errors, to judge the accuracy of adjustment of photogrammetric blocks. Even in some cases, if the practical and theoretical distributions of frequency interval agree, such a test does not make it possible to establish the closeness of their convergence nor the degree of their difference. In other words, to get a complete picture of the character of the distribution of errors in the adjusted photogrammetric blocks, it is insufficient to investigate any single statistic. In the Research and Development Section of the Topographical Survey Directorate, a computer program (SABA) has been designed to analyze the errors of photogrammetric block adjustments, compute various statistical parameters and check the sample distribution using Kolmogorov criterion. Based on the decision taken, the correspondence between the empirical and theoretical distribution series are checked using the criterion χ2. The program divides the adjusted block to make a comparative evaluation of accuracies in the different sub-blocks. In this case, in addition to Kolmogorov and χ2 tests, the program checks the reliability intervals of the means and mean square errors of the samples and uses Fisher criterion ‘F’ to check the hypothesis of the equality of dispersion. SABA is coded in Fortran IV and Compass for the CDC CYBER 74 and requires a central memory of 28K decimal works. SABA is the acronym for Statistical Analysis of Block Adjustment.
Evaluation of Sopelem Presa 226RC Plotter for Independent Model Triangulation
Authors: Moffitt Francis H. 
Published: July 2019

The Presa 226RC is a first-order stereorestitution instrument accepting wide angle and super wide angle aerial photography. It is relatively unknown to photogrammetrists in North America. It was tested for the stability of its perspective centers, accuracy of plate measurements, and its suitability for independent model triangulation. Departure of perspective center coordinates from instrument zero position when moved through maximum rotational range amounts to 0.04 mm in x, 0.04 mm in y, and 0.02 mm in z. Base component displacements by" and bz’ needed in relative orientation cause an apparent shift of about 0.03 mm in all three directions. Standard deviations of plate coordinates of 20 grid intersections used in perspective center stability tests are: σx′ = ±0.007 mm, σy′ = ±0.007 mm, σx″ = ±0.006 mm, and σy″ = ±0.004 mm. Independent model triangulation of four separate short strips of a heavily controlled area was adjusted by Schut’s 2nd degree polynomial adjustment. Standard deviations at plate scale are σx = ± 0.012 mm; σy = ± 0.012 mm. The relative accuracy of vertical control points is about 1/8,000 of the flying height.
A Comparison of Precision Alignment Methods
Authors: Chrzanowski Adam , Jarzymowski Andrzej , Kaspar Milan 
Published: July 2019

The following four methods of precision alignment surveys have been compared on a 816-m test line: 1) conventional optical alignment with a DKM-3 telescope and movable targets, 2) conventional traversing with forced centering using a closed (loop) traverse, fitted traverse and a narrow triangles method, 3) direct alignment with a collimated He-Ne laser and photoelectric targets, 4) diffraction method employing Fresnel zone gratings, He-Ne laser and photoelectric or visual centerings. Fourteen alignments of points B and C (Figure 1) on the line A-D were performed in different atmospheric conditions. Measurements of horizontal gradients of temperature indicated that discrepancies of up to 8 mm in the alignment could be expected because of the side refraction effects. Results of the alignments are listed in Tables 1 and 3. Laser alignments were performed with prototypes of instruments (Figures 5, 6, 8 and 10) that had been designed and constructed at the University of New Brunswick.
The Effect of Ambient Conditions on the Accuracy of the Estimation of Distance and Angle Measurements in Large Geodetic Networks
Authors: Ahmed Fouad A. 
Published: July 2019

The change in variances in microwave distance measurements and in angle observations obtained on different terrain and under different meteorological conditions is investigated. The value of reading the wet bulb thermometer plays the main role in determining the accuracy of the refractive index. A simplified formula is derived for the calculation of the standard deviation of the measured distance in ppm at different dry and wet bulb thermometer readings. The formula is applicable to all wet bulb readings above the melting point. Geodetic triangle misclosure and its variance in three extensive samples were statistically analyzed. The samples were chosen according to the type of terrain covered. It was found that side refraction and deflection of the vertical contaminated the chosen samples and that hypothesis of equal variances in such samples cannot be statistically accepted. Accordingly, relative variances in angle measurements are recommended for consideration for the simultaneous adjustment of large geodetic networks.
Gravity Field Approximations Using Inertial Survey Systems
Authors: Schwarz K. P. 
Published: July 2019

Inertial survey systems can be used to determine changes in the anomalous gravity vector. The underlying principle and the resulting estimation procedures are discussed in this paper. The analysis of the measuring procedure shows that the observed quantities are dependent on the second-order gradients of the anomalous potential. Thus, the usual representation by the first-order gradients does not adequately model the measurements. The model proposed in this paper considers theoretical as well as practical requirements. The estimation of gravity field changes is done by optimal filtering. The time-dependent system of differential equations representing the system errors is augmented by a set of parameters that model the anomalous gravity vector as a position-dependent quantity. This leads to a nonlinear estimation problem. Quasilinearization is discussed as one of the possible solutions. The first-order approximation of this solution is a linear estimation problem and thus can be compared to the filtering methods used in present day systems. Questions of implementation are discussed and some open problems are outlined.
Photogrammetric Methods in Transmission Line Projects
Authors: Huegli P. , Leupin M. M. 
Published: July 2019

Within the project of high-tension transmission lines, Hydro-Québec measures a traverse along the center line and maps a strip of approximately 500 m at 1:2 500 scale by photogrammetric means. Up to now, the aerotriangulation of the 1:12 000 image scale strips was mainly based on inertial control points, while the center line traverse was not used for photogrammetric control. Because of the limited width of the band to be mapped, these traverse points could be useful. This paper deals with a study on the influence of the central traverse (used as photogrammetric control) on the accuracy within the 500-m band. For this purpose, tests with simulated and real data were carried out applying a rigorous mathematical model. The results show that the inertial points can practically be left out and that the central traverse with a few additional control points assures sufficient accuracy. With a $ 2 600 (1980) price tag for an inertial point, this procedure results in substantial savings.