bluuebunny/crossref_metadata_2025 huggingface dataset:
Patterns of Aerial Photo Weather in Canada
Authors: FLEMING J.
Published: July 2019

Weather suitable for high altitude aerial survey photography is defined in terms of cloud cover, horizontal visibility, and solar altitude. With these criteria established, relevant weather observation data, stored in the electronic archives of the Meteorological Service of Canada, were selected and used to compute a single figure value of average frequency of occurrence for each observation station, each month, for each of two minimum solar altitudes. Isopleths were then plotted on suitable base maps to depict the mean frequency of occurrence of observations meeting the criteria over a 10-year period.

During the study of the accumulated data, it became apparent that four major areas which exhibit distinctive zonal photo weather patterns are to be found in Canada. Possible reasons for the existence of these zonal distributions are discussed in terms of their regional and local, geographical and meteorological characteristics.

The information presented is statistical. Because of the nature of the computer program used to select data it was, unfortunately, not possible to compute standard deviations from mean values. This and other limitations on the application of the data to specific cases are discussed.
Integration of Satellite and Decca 12F Survey Systems
Authors: Hittel A. , Kouba J.
Published: July 2019

Shell Canada Limited Exploration and Production Calgary, Alberta

Geographic coordinates derived from the Navy Navigation Satellite System (NNSS) are based on the Applied Physics Laboratory Reference Ellipsoid. This ellipsoid does not correspond to the Clarke 1866 Ellipsoid presenting the somewhat confusing problem of datum transformation.

Reliable techniques used to compute the various datum transformations are described and the required formulas for computing the corrections are given. Derived corrections are compared with field results obtained during the 1970 offshore geophysical operations.
Changing Role of Image Interpretation
Authors: Kalensky Zdenek D.
Published: July 2019

Image interpretation used to be, and often still is, a marginal specialization within many professions. Because of a lack of adequate research and educational facilities, it has been poorly equipped to cope with the rapid progress in the related field of remote sensing. As a consequence, a large disparity exists between the rate of data recording and their utilization.

To rectify this situation, image interpretation should be a discipline in its own right. The emphasis must shift from applications, which should remain in the domain of professionals in disciplines using the data, to fundamental aspects which are common to all disciplines. A two-stage scheme of image interpretation based on teamwork between an image analyst and a specialist in a particular field of application is discussed, so too is its impact on the role of image interpretation.
Deviation of Solar Culmination from Meridian Transit in Polar Regions
Authors: Johnson G. W. , Lillestrand R. L.
Published: July 2019

Solar culmination does not occur precisely at meridian passage except at the time of summer or winter solstice. The extent of the deviation between culmination and meridian passage is analyzed with particular emphasis on the polar regions, where the deviation reaches its maximum. As the Pole is approached, a zone is reached within which no culmination whatsoever occurs. Graphs are given that show the zenith angle difference, the local hour angle and the azimuth angle at the time of culmination as a function of the observer’s latitude and the time of the year.
Legislation for Urban Surveying and Mapping
Authors: Smith Ralph A.
Published: July 2019

The lack of understanding of administrators of the need and importance of accurate survey and mapping records is reflected in the complete lack of legislation in this area. An amendment to the Municipal Act requiring the development of a survey data base for urban areas is suggested. The benefits to be derived, the methods of obtaining the data and the cost considerations are discussed. Until surveying and mapping are considered separate services to be provided, and municipal responsibilities in these areas are spelled out, the private and public sectors will be denied the benefits of reduced survey costs and increased information.
Man-Machine Photogrammetric Systems and System Components
Authors: Jaksic Z.
Published: July 2019

Under the influence of ideas from control and communication theory, new trends have developed in the design of photogrammetric data-processing systems. In this paper a number of concepts applied to the design of such systems are discussed, with emphasis on the digital man-machine systems and system components. The main characteristics of contemporary photogrammetric systems are outlined in regard to both their hardware and software, including some remarks on automation and orthophototechniques. The general descriptions are supported by examples from two systems: one predominantly digital and the other predominantly analog. These examples concern the instrumental developments in the Photogrammetric Research Laboratories of the National Research Council of Canada.
Temporal Analysis of ERTS Imagery in the Boreal Forest Region
Authors: Kirby Charles
Published: July 2019

This paper presents an evaluation of ERTS imagery for forest inventory in the boreal forest region. The work illustrates that, by combining phenological knowledge and seasonal variations with the knowledge of spectral reflectance patterns, the interpretation of forest cover types from ERTS imagery is improved.
Evaluation of ERTS Imagery for Vegetation Interpretation in British Columbia
Authors: Oswald E.T.
Published: July 2019

ERTS imagery has provided a means of surveying the natural resources on the earth’s surface by multiband, small-scale sequential imagery. This is a new tool for taking an inventory of natural resources. It requires evaluation for different purposes.

The imagery was evaluated for distinguishing vegetation communities. Nonforested land could be easily separated from forest land and some distinctions could be made within these broad categories. Cut-over forest land, some meadows, grassland and highly developed urban land (towns) could be separated within the nonforested land. Differently aged forest stands, either from fire or reforestation, could be distinguished within the forested areas. Tree species could not be separated except through knowledge of successional patterns in some areas. Major forest types were generally not separable.

The results and conclusions are tentative because equipment for image analysis was not available and only two sets of imagery of study areas were available: one in mid-May and one in mid-August.
Interpretation of ERTS Imagery in Biophysical Surveys
Authors: Gimbarzevsky P.
Published: July 2019

Four bands of ERTS imagery were analyzed under a stereoscope by pairing paper prints of bands 4, 5, 6 and 7 in an attempt to apply a conventional air-photo analysis method for extraction of basic information on physical characteristics of the land and its biotic components. The overview of an extensive land area at the 1:1,000,000 scale provides an adequate base for a general stratification of the land surface into broad physiographic landscapes (mountains, foothills, uplands, plains and lowland) and for recognition of major geomorphic processes from the analysis of drainage pattern, vegetation and erosional features. Some limitations of the ERTS imagery for a detailed mapping of landforms are illustrated by a comparison of conventional small-scale photographs and a section of ERTS imagery enlarged to the same scale.
The Assessment of Angular Measurements with the Lambert Instrument Tower
Authors: Smith W. M.
Published: July 2019

The surveying profession has long needed a lightweight, easily erected instrument observing tower. The Lambert Instrument Tower was developed to fill such a need within the International Boundary Commission. The tower has been in use over the past three field seasons. Several towers have also been erected on the Geodetic Survey test network for test and development purposes. Towers have been limited to 60 feet in height. However, no serious difficulties are anticipated in developing towers to greater heights.

This paper describes recent developments on the tower and presents an assessment of angular test measurements that indicate that a standard deviation of less than one second can be expected when observations are made with precise instruments from the tower.
A Study of the Geoid in Canada
Authors: Lachapelle Gérard
Published: July 2019

An astrogeodetic determination of the geoid in certain parts of Canada was made with data available at the end of 1970. The astrogeodetic leveling method was used. The western and eastern parts of Canada were adjusted independently owing to the lack of data in the Province of Ontario. Five satellite stations located across Canada were chosen as initial points of the astrogeodetic geoid. Comparisons with two other astrogeodetic geoids — U.S. Army Map Service 1967 and University of New Brunswick 1973 — and one geoid obtained from a combination of gravimetric and satellite data— Goddard Space Flight Center 1972 — were made. A relative agreement of about five metres was found in every case for most parts covered by the present astrogeodetic geoid except in Newfoundland and Yukon.
The Role of the Geoid in Datum Definitions
Authors: Fischer Irene
Published: July 2019

A geodetic datum is a mathematical means to adjust and record a network of control stations. The reference surface chosen for the adjustment of the horizontal control is essentially arbitrary, but expected to fit the geoid of the area reasonably well. The geoidal separation computed from the adjusted control is an indicator of the fit. When choosing a new datum, this indicator may be used to clarify the alternatives, so that the choice will serve the purpose.
Impact of Satellite Altimetry on Geodetic Datum Definition
Authors: Fubara D. M. J. , Mourad A. G.
Published: July 2019

Based on results of the geodetic calibration and analysis of Skylab altimeter data, the concept of determination of the geoid in the oceans — the marine geoid — from satellite altimetry has been demonstrated. In principle, the satellite altimetry geoid should combine and improve on all the strong features of the gravimetric, astrogeodetic and satellite-derived geopotential coefficient geoids in terms of scale, shape, and absolute orientation. The criteria for achieving these conditions have been discussed with supporting investigations in other publications by the authors. It is shown that the satellite-altimetry-derived marine geoid, which could cover about 70 per cent of the world, can be used for 1) modification of scale, shape, orientation, and centering of the various geoids in each continent to achieve uniformity and compatibility that currently do not exist, and 2) improved intercontinental ties between computed geoids and geodetic datums of the various continents. Achievement of these objectives will contribute to a better definition of the figure of the earth and geodetic datums required for adjustment of geodetic networks.
Three-Dimensional Model Based on Hotine’s “Mathematical Geodesy”
Authors: Chovitz Bernard
Published: July 2019

Three-dimensional model in essence means employing all possible observables within a unified solution. However, in the context of application to the redefinition of North American networks, we are speaking primarily about the classic observables over intervisible distances, and the ensuing discussion is limited to this application. In addition to the observation equations produced by Hotine, the observation equation for spirit level rise is derived. It is concluded that, owing to the lack of vertical angles and level differences, the three-dimensional approach would not appear practical for the redefinition in North America. However, the three-dimensional approach should be used in selected areas, where there are enough required observations available.
Role of Artificial Earth Satellites in Redefinition of the North American Datum
Authors: Anderle Richard J.
Published: July 2019

Satellite observations provide a reference frame for terrestrial survey whose origin is within one metre of the center of mass of the earth, whose z-axis is parallel to the CIO pole to the equivalent of five metres at the earth’s surface, and whose scale has an accuracy of about a part per million. A convention needs to be adopted to define the longitude origin. A well adjusted terrestrial network can be transformed to this system to about one-metre accuracy. Densification of the terrestrial network can be accomplished to 1.5 metre accuracy with the use of less than four days of Doppler observations for each site.
Geodetic Networks in Space
Authors: Marussi Antonio
Published: July 2019

The computation of geodetic networks has been carried out by establishing a correspondence between points of the actual physical surface of the earth and points of the reference ellipsoid and by treating elevations separately. This approach does not seem to be tenable any longer in view of the modern needs of space geodesy.

It is therefore suggested that the classical procedure should be generalized by establishing a one-to-one correspondence between points of the actual physical surface of the earth and points of the reference ellipsoidal field and by using subsequently the metric properties of this field for computations. In this procedure, elevations are treated simultaneously with horizontal control, and the large distortions introduced by the projection onto the ellipsoid are avoided.
An Integrated Approach to Map Projections and Plane Coordinates
Authors: Wray Thomas
Published: July 2019

A redefinition of the North American geodetic networks may well require a reappraisal of the various plane coordinate systems in use in North America. Now “plane coordinate system” and “map projection” are really only different names for the same thing. An approach to coordinate conversion is described in which each map projection (plane coordinate system) is not analyzed as an individual, but the whole set of map projections is regarded as an integrated system. The various projections are displayed in a “family tree” and conversion between two coordinate systems is performed by following the most direct path in this tree. The advantages of this approach are that 1) reduction to latitude and longitude as an intermediate step is usually unnecessary and 2) the individual steps in the tree are usually quite simple mathematically owing to the flexibility in the parameters used. The traditional approach using latitude and longitude as essential parameters often leads to ugly mathematical functions best approximated by Taylor series whose coefficients may be quite awkward to determine.
Partial Solution ofthe Variance-Covariance Matrix for Geodetic Networks
Authors: Knight William , Steeves Peter
Published: July 2019

For a positive definite symmetric band plus border matrix, N, this paper describes a computation of only those elements of S = N–1 that lie in the band plus border pattern of N. For large matrices with narrow bands and borders, this computation may be feasible where full inversion of N would be too costly. An 832 by 832 matrix with band width 20 and border width 16 required less than two minutes CPU time on an IBM 370 model 158.
The Condition Method in the Adjustment of Large Networks
Authors: Allman J. S.
Published: July 2019

The problems of adjusting large networks are discussed and a method detailed that overcomes the problems. The method involves an extension of the Kruger technique and is explained through a simple numerical example. The procedures to be followed in the adjustment of a large network are outlined, showing how both the parametric and condition methods each have a place in the future of network adjustment.
Generalized Inverse as a Weight Matrix
Authors: Uotila Urho A.
Published: July 2019

In several textbooks, the least-squares solutions are given with generalized matrices, but usually the weight matrix is assumed to be a positive definite matrix especially when weight matrix has off-diagonal elements. A more general solution is presented in which a generalized inverse is used as a weight matrix.
Applications of Statistical Characteristics of Geodetic Networks
Authors: Gale L. A.
Published: July 2019

Numerous statistics that can be obtained from the processing of the observations and the adjustment of a geodetic network can be used to assess the quality of the network and the observational data. The processes used for assessment and planning depend on the needs and the capabilities of the user. Statistical information derived from nonsingular vis-à-vis singular (“inner-constraint”) adjustments is discussed. Standards for the characterization of the quality of networks are reviewed. Suggestions are made on the type of information that should be directly available from a geodetic control file.
Time and Heights
Authors: Holdahl Sandford R.
Published: July 2019

To use leveling most effectively in determining crustal movements, it is necessary to have two sets of precise measurements separated by a reasonable time interval. But this is not enough! It is necessary that systematic errors that vary with time must be removed. As an example, an astronomical correction of 70 millimetres is computed for a line running from Spokane, Washington, to San Diego, California, (12° latitude change). A systematic refraction correction of 33.8 millimetres over a line 46 kilometres long in California is computed using average weather data. It is recommended that such corrections should be applied in computing crustal movements, and it is suggested that a map of rates of vertical movements in North America would be useful.
The Impact of the Redefinition on the Surveying Community
Authors: Dracup Joseph F.
Published: July 2019

By adopting an earth mass centered ellipsoid for the redefinition of the North American Datum, the greatest impact will be felt primarily by the cartographic community and, to a somewhat lesser degree, in those areas where integrated survey systems have been established. Boundary demarcation problems may arise, but it is expected time honored legal acceptances will prevail. Since multipurpose use of the Datum is increasing, this seems the most opportune time to make the new adjustment, prior to reaching that period where reluctance to any change would be more universal.
Aerial Photographic Investigation of Shortcut Canal on the Grand River, Ontario
Authors: Jackson H. Ross
Published: July 2019

A method is suggested by which surveyors can use aerial photography to determine positions of lost boundaries. As an example, the course of a ’disused canal’, which is depicted on an early NTS map sheet of Dunnville, Ontario is studied. A ground survey of the site reveals little evidence that a waterway ever existed. Aerial photographic interpretation was used to determine the location and length of the canal and to confirm its course as shown on early maps of the area.
Remarks on Dr. A. Bujakiewicz’ Paper, “The Correction of Lens Distortion with Polynomials”
Authors: Ziemann H.
Published: July 2019

Using the same data as Dr. Bujakiewicz, three questions posed in her paper were investigated further.
Research on the History of Cartography and Historical Cartography of Canada: Retrospect and Prospect
Authors: Ruggles Richard I.
Published: July 2019

The events leading to the recent organization of historical cartographers are reviewed as well as the details of studies of various historical cartographers of Canadian maps dating from the first explorers to the most recent productions. Most of these have been studies of maps as documents providing information rather than studies of the science or art of cartography.
The Atlas of Inuit Land Use Comments on Map Design
Authors: Head C. Grant , Hawley Bryan G. , Coutts Pamela J.
Published: July 2019

As a prelude to Eskimo land-use claims, 85 percent of male Eskimos were interviewed for information on their use of land for presentation in atlas form. A 9 × 12 inch format was used to make the information readily available at the least possible cost. This required many difficult design decisions for the clear presentation of land use and species habitation in many large overlapping areas. The resulting atlas of 230 full-color map plates costs $14.00.
Map User Research and Modern Road Map Design
Authors: Anderson Jacqueline M.
Published: July 2019

Within cartography the realization of the need to understand the whole process of map communication is a relatively recent development. Road maps are widely used by the North American general public yet very little is known about their use. A survey was conducted to obtain information on the use of the 1974 Official Alberta Road Map. Based on the findings of this survey and a brief examination of the contents and design of comparable road maps, suggestions are made for the improvement of road maps.
Land Economy: An Education and Philosophy for the Surveyor’s Profession
Authors: Denman Donald
Published: July 2019

The role of the professional land surveyor has been decreasing in importance because he has not pursued his legitimate role as an adviser in land management. The University of Cambridge has, over the last 16 years, developed a land economy course that includes land law, land economics, economics, agricultural and resource development, environmental policies, etc. Similar courses have been set up in many Commonwealth countries. Such courses can equip surveyors to provide the professional services that should be his preserve.
The LRIS Approach to Redefinition of Geodetic Networks in the Maritimes
Authors: Fila Karel , Chamberlain Charles
Published: July 2019

Background information on the establishment of the geodetic networks in the Maritime Provinces and the need for a redefinition of the network are given. Project planning has been completed and the master plan, which outlines the main segments of the implementation, is presented. The requirements for a Maritime geodetic data bank, which is being created in conjunction with the project are outlined. Finally, a progress report (December 1976) of the project is presented.
Doppler Satellite Application in Manitoba
Authors: Hittel Alex , Wade R. L. , Leeman F. W.
Published: July 2019

First and second order horizontal and vertical survey control can now be established by the use of third generation Doppler satellite receivers together with rigorous three-dimensional satellite computer programs. The Survey System (NNSS) makes use of the six polar satellites to determine coordinates in X, Y, Z components and latitude, longitude and elevation to better than one metre.

Major refinements in 1974 in both hardware and software make it possible to achieve these high-order precisions even with the use of the predicted broadcast ephemeris. The use of broadcast ephemeris has doubled the field production compared to precise ephemeris methods.

A field design is employed that provides a sound solution to previous problems associated with scale, orientation and integration. The paper shows how a large number of stations determined by satellite observations can be integrated and adjusted to geodetic networks. This paper describes the methods employed and the accuracies achieved during a satellite Doppler program conducted in the province of Manitoba, Canada, during 1976. The operational aspects encountered during a Manitoba winter are discussed. The paper illustrates how geoid-spheroid separations are enhanced by the knowledge gained in Doppler satellite control surveys.

Survey objectives are discussed including the satisfactory fulfillment of requirements for (a) the production of 1:20 000 photo base maps, and (b) the development of a land identification system for computer handling of resource data.
Readjustment of Canadian Secondary Horizontal Control Networks
Authors: McLellan C.D. , Henderson J.P. , Boal J.D.
Published: July 2019

The readjustment of the Canadian secondary and lower order control networks is scheduled to take place in 1983 following the adoption of new primary framework values. Some 200 000 points are involved. 75 000 of which are the responsibility of the Geodetic Survey. These networks are to be evaluated, strengthened, densified and extended as necessary, prior to integration. The project will be done by regions defined, for the most part, by arcs of framework control. Secondary networks will be integrated with the framework by least squares adjustment; some lower order control may be recomputed by an approximate method. Considering the amount of secondary control to be readjusted, it is essential that agreement on the sharing of responsibilities between the federal and provincial agencies involved be reached at an early stage.
The Development of the Inertial Rapid Geodetic Survey System at USAETL
Authors: Todd Mark S.
Published: July 2019

This paper addresses the development of an inertial navigation system into a land-based geodetic survey system by the United States Army Engineer Topographic Laboratories from the Position and Azimuth Determining System (PADS) to the Rapid Geodetic Survey System (RGSS). It contains a brief description of the inertial platform and its operation to obtain position, elevation, gravity anomalies and deflections of the vertical. A summary of test results are included. Potential utilization and improvements are also addressed.
Computer Program MANOR
Authors: Barber J.D. , Fulford F.B. , Dhalla Z.K.
Published: July 2019

MANOR, a multipurpose computer program for checking, auditing, adjusting and designing horizontal control survey networks, has been written under the sponsorship of the Ontario Ministry of Natural Resources. It is designed to he simple to use and highly efficient. This paper presents an overview of MANOR.
The Surveying Requirements for Deep-Draught Routes
Authors: Haslam D. W.
Published: July 2019

Less than a third of the world’s continental shelves has been surveyed by echo sounder, the rest, if surveyed at all, has been covered only by hand-lead and line. Large rocks and wrecks undoubtedly lie undetected between individual casts of the lead and even between quite modern echo sounding profiles. The draught of merchant ships has doubled since the 1960s. Minimal underkeel clearances are now accepted and many new routes are being used across the continental shelves between offshore energy exploitation platforms and new shore terminals.

Examples are given of typical shelf surveys and of various ways of meeting modern requirements, including the use of multiple echo sounders, sidescan sonars and sector scanning sonars. Reference is made to the effects on charting of the increasing amount of data available on individual wrecks and seabed obstructions as well as the use of traffic separation schemes. Attention is drawn to the need to monitor the depth in unstable seabed areas, the effect of negative surges and the need for source-data diagrams on charts.
Application of Computer Technology in Processing of Cadastral Surveying and Mapping Data
Authors: Cremont Daniel
Published: July 2019

During the past ten years, the Institut Géographique National, France (IGN-F), has gained useful experience in the fields of large-scale digitized mapping and data bank management.

This paper presents a land information system that would be suitable for developed countries where the updating and matching of topographic and cadastral maps are planned within the framework of an integrated system, as well as for those countries where large-scale maps are not available but the level of development justifies the investment.

One simple, flexible system should be established, sophisticated equipment should be avoided, and the data processing limited to reasonable applications.

Detailed descriptions of data collecting with stereoplotters and digitizing tables as well as data processing are given. Original methods for processing data for the production of cadastral maps are also presented.
High Accuracy Photogrammetric Determinations Using Image Deformation Corrections
Authors: Ziemann Hartmut
Published: July 2019

This paper summarizes considerations related to the use of photogrammetric procedures for the surveying of cadastral boundaries and for the densification of control point nets. It gives an overview of a number of analytical aerial triangulation results and examines the effectiveness of various procedures for the elimination of the effects of image errors. Sources of image errors and procedures for the correction of the effects of these errors are also reviewed.
Experience with Computer Processing and Storage of Data in a Project of Cadastre Renovation
Authors: Klingenberg F. , Andris H. R.
Published: July 2019

Land information can be well depicted on plans and maps. However, as change and development take place the maps become antiquated and unreliable. A cadastre renovation program in Switzerland has made it possible to continue to use information depicted on old maps. Essentially, the program entails the establishment of a strong control network and accurately connecting features on the old maps to this control.

A graphic-numerical interactive system has been established to deal with the data, and all points on the old map sheets have been digitized and coordinated.
Effects of Ambient Conditions on Film Sensitivity
Authors: Carman P. D. , Johnston S.F.
Published: July 2019

In practical use, photographic films are often subject to ambient conditions of temperature or humidity that are far from optimum, and that are difficult or almost impossible to avoid. Although efforts should always be made to follow film manufacturers’ recommendations on handling films in good ambient conditions, it appears desirable to have quantitative information available on the effects of various departures from optimum conditions and on techniques for minimizing adverse effects.

Information based on practical experiences and on research studies in several Canadian organizations is reported. Data are provided, for certain samples of color and black and white film, on the sensitometric effects of storage for various times and at various elevated temperatures, both before and after exposure. Low humidity in flight causes adverse effects on color, which are easily avoided. Problems can arise in transferring film from cold storage to camera and in handling between exposure and processing.
Block Adjustment of Bundles
Authors: Schut G. H.
Published: July 2019

The characteristic features of programs for the block adjustment of bundles are described in the context of their historical development, and the approach used in the program developed by the author at the National Research Council of Canada is explained. This is followed by a more detailed account of the latter program. Finally, the results obtained by using added parameters, which serve to correct for systematic errors during the adjustment, are shown.
Atmospheric Temperature Models for Short-Range EDM
Authors: Angus-Leppan P.V. , Brunner F.K.
Published: July 2019

For short-range electronic distance measurements (EDM) of the highest accuracy, an additional correction is needed to account for the difference between meteorological values at the end points and along the path of the measurement. Models are developed making use of formulations for the temperature gradient derived from atmospheric physics. The corrections depend on the surface profile below the line. For unstable atmospheric stratification the main meteorological parameter is the upward heat flux H. For a stable atmosphere, additional parameters are surface roughness and wind speed. Calculation of a typical example shows that under unstable atmospheric conditions the additional correction can be over 2 ppm, and for a stable atmosphere it may reach 4 ppm.
Empirical Determination of the Gravity Anomaly Covariance Function in Mountainous Areas
Authors: Lachapelle Gerard , Schwarz K. P.
Published: July 2019

An evaluation of the empirical gravity anomaly covariance function using over 95 000 surface gravity anomalies in the North American Western Cordillera was carried out. A regression analysis of the data exhibits a strong and quasi-linear correlation of free air gravity anomalies with heights. This height correlation is removed from the free air anomalies prior to the numerical evaluation of the gravity anomaly covariance function. This covariance function agrees well with that evaluated previously by the authors for the remainder of Canada. A possible use for such a covariance function of ‘height independent’ gravity anomalies in mountainous areas is described. First, the height independent gravity anomaly at a point of known height is evaluated by least squares prediction using neighboring measured height independent gravity anomalies. Secondly, the part caused by the height correlation is calculated using linear regression parameters estimated previously and added to the predicted height independent gravity anomaly to obtain a predicted standard free air anomaly. This technique can be used to densify the coverage of free air anomalies for subsequent use in integral formulas of physical geodesy, e.g., those of Stokes and Vening Meinesz. This method requires that point topographic heights be given on a grid.
Error Propagation in Inertial Positioning
Authors: Schwarz K. P.
Published: July 2019

To combine the results obtained from inertial surveying systems with other geodetic data the complete error covariance matrix for the derived positions is required. This matrix is not available from the standard output.

It is shown how the covariances at each station can be obtained from the system of differential equations that governs the error propagation and how filtering and smoothing procedures effect the error estimates. The covariances between stations on the same traverse are then derived and the formulas are used to compute the correlation matrix for a test traverse near Ottawa, Ontario. The correlations are large for standard zero update periods and they increase with time. The results are checked by performing a correlation analysis on actual data along the same traverse. Correlations are even larger in this case, indicating an almost deterministic error behavior for the individual traverse.
The Preparation of Loran-C Lattices for Canadian Charts
Authors: Gray David H.
Published: July 2019

An overview of what Loran-C is, how it works and how it is presented on a chart is given. Particular attention is given to the Additional Secondary Factor (ASF) and how the Canadian Hydrographic Service (CHS) incorporates it in its preparation of lattices. The method of prediction of Time Differences (TD) and the verification of both the propagation theory and of the TD values are done using Time of Arrival (TOA) measurements. The technique of computer controlled automated drafting of the Lines of Position (LOP) and how the ASF anomalies are accommodated in the lattices are outlined, so that the LOPs are in their true geographical location. The quality of the Loran-C signals has been surveyed by the CHS and this is reflected in its choice of lattices on a chart and the application of caution notes where necessary. The rationale of selection of lattices for various versions of charts is discussed.
Kingston Harbour Magnetic Anomaly
Authors: Newitt L. R. , Dawson Edward
Published: July 2019

The existence of a magnetic anomaly located in Kingston Harbour, Ontario, has been known for more than a century. Based on declination observations taken in the region, a chart is constructed showing the amount by which the declination differs from the regional value of 11.5°W. Residual values range from −16.3° to 15.5°.

The total force anomaly appears to be centered at 44° 12.8’N, 76° 30.1’W. At its maximum value of 12 800 nT (nanotesla), it represents 24 percent of the normal field strength. By modeling this anomaly, the anomalous declination pattern is approximated to within 2.7°. In areas where anomalies affect navigation, and only total force observations are available, this procedure may provide useful declination information.
An Argo-Based Positioning and Navigation System for the Labrador Coast
Authors: Lockhart J. T. , Nickerson B.G. , Smith J. W. K. , Thomson D. B.
Published: July 2019

During June to October 1979, a chain of mediumwave length radio positioning system stations was operated on the Labrador coast. These stations provided the basis for general navigation, drill-ship positioning, seismic site surveys and current meter deployment and recoveiy up to 170 kilometres off the Labrador coast. This chain provided coverage along 800 kilometres of coastline.

The paper gives an overview of both shore and mobile station components and operation. Details are presented regarding the system calibration and its combination with Doppler satellite positioning. Descriptions of the HP 9825S system software, used for system computations, are given. Accuracy estimates, based on internal and external checking procedures, are presented. Other performance factors, such as day/night achievable ranges and system reliability based on five months of operational activity, are discussed.
Transformation of Conformai Projections for Graphical Purposes
Authors: Doytsher Y. , Shmutter B.
Published: July 2019

Rigorous and approximate procedures for transforming coordinates from one conformal projection to another are discussed. The proposed procedures are expedient in terms of computational efforts and the results provide an accuracy that complies with the requirements of graphical display of data. Computed examples illustrate these procedures.
David Thompson’s Determination of Longitude in Western Canada
Authors: Sebert L. M.
Published: July 2019

This paper describes the lunar distance method of determining longitude which was used by David Thompson to provide longitude control for his maps of Western Canada. The series of 34 readings taken by Thompson at Cumberland House between February and May 1790 are examined to show that Thompson was adept in this method of surveying.
Cadastral Studies in the Surveying Engineering Program at The University of Calgary
Authors: Teskey W. F. , Swanby T. C.
Published: July 2019

The surveying engineering program at The University of Calgary, as of September 1981, has been in operation for two years. It is now fully operational, and successful by any measure.

Cadastral studies area courses and other closely related courses form an important component of the program. These courses are described and discussed. The role of the Western Canadian Board of Examiners for Land Surveyors and its relationship to the surveying engineering program at The University of Calgary is also outlined.
NAVSTAR/GPS — Present Situation and Future Prospects
Authors: Boal J. David
Published: July 2019

Although the U.S. Department of Defense is developing the NAVSTAR/Global Positioning System (GPS) for its military positioning and navigation requirements, there are obvious civilian benefits to be gained from exploiting this global satellite system. No present navigation system offers the continuous worldwide accuracy in time and position which GPS will deliver. Even now, with only four prototype satellites in operation, GPS users have demonstrated that the accuracy of the system has exceeded design goals. Future applications will include geodynamics, the unification of geodetic datums, surveying, mapping, navigation, hydrography, offshore resource exploration and development, and marine and air traffic management.
NAVSTAR/GPS Single Point Positioning at Sheltech Canada — Preliminary Results
Authors: Lachapelle GÉrard , Beck Norman
Published: July 2019

Sheltech Canada’s active involvement in the use of Navstar/GPS for positioning was highlighted by the acquisition, in mid 1980, of a second generation geodetic receiver from Stanford Telecommunications Inc. of Sunnyvale, California, U.S.A. A brief description of Sheltech’s STI 5010 GPS receiver, auxiliary equipment and real-time software required to operate the system is presented. Mathematical models and least-squares algorithms used to derive three-dimensional positions from pseudorange observations are described. Related validation tests carried out over several months indicate that the anticipated 10-m accuracy (1 σ level) for instantaneous single point positioning, predicted for the fully operational GPS constellation starting in 1987, is already achievable for certain periods of time. Sheltech’s future plans regarding offshore and land positioning, and the integration of the GPS receiver system with other navigation aids, e.g., inertial systems, are summarized.
The Labrador Boundary
Authors: McEwen Alec
Published: July 2019

This paper traces the history of the Labrador boundary dispute, examines the principal arguments put forward by each side and considers the judicial findings. It attempts to clear away any misconceptions that may still persist concerning the present legal validity of the 1927 decision.
Auxiliary Spheres of Common Spheroids
Authors: Wray Thomas , Weiss Carolyn C.
Published: July 2019

The concept of a sphere auxiliary to a spheroid (ellipsoid of revolution) is defined, seven common spheroids are identified, and six auxiliary spheres are discussed for each of the spheroids. The radii of these forty-two spheres are tabulated in metres and in nautical miles. Mathematical definitions of the quantities discussed are given.
Magnetic Declination in Canada from 1750 to 1980
Authors: Dawson E. , Newitt L. R.
Published: July 2019

Tables of magnetic declination for the period 1750-1980 have been compiled for 122 locations in Canada. These are intended primarily to assist surveyors who require such information when retracing old survey lines. Estimated errors vary from ±1.5° prior to 1850 to ±0.5° for the present century.

Simplifed declination charts for the years 1800, 1850, 1900 and 1980, and secular variation graphs at selected sites illustrate the complexity of the secular variation in Canada during historic times.
The Survey of Mineral Permit Areas and Claim Blocks in Saskatchewan
Authors: Babiuk D. , Desnoyers E. J.
Published: July 2019

Mineral disposition surveys in Saskatchewan have entered a new era. In this paper the general principles and regulatory aspects involved in the survey of Permit Areas, described by geographic coordinates, and Claim Blocks, defined by claim posts, are elucidated with emphasis on the land surveyor’s responsibility in establishing priority of mineral rights. The mechanics of handling ‘open ground’ areas between dispositions is also addressed.
Boundary Marks and Benefit of Clergy
Authors: McEwen Alec C.
Published: July 2019

Early crimes, including the unlawful removal of boundary stones, were often punishable by death. Convicted prisoners could sometimes escape execution by claiming the benefit of clergy, a legal plea that originated as a church privilege and later became a simple literacy test. Benefit of clergy survived in some parts of North America until the mid-nineteenth century.
GPS Satellite Surveying — Practical Aspects
Authors: Hothem Larry D. , Goad Clyde C. , Remondi Benjamin W.
Published: July 2019

No satellite-based survey system has gained as much attention and interest as the Global Positioning System (GPS). Establishing precise positions by use of the GPS is rapidly becoming a powerful and economical tool for surveyors. The extensive experience gained at the National Geodetic Survey (NGS), from field tests in March 1983 to operational projects performed later in 1983 and early 1984, has demonstrated that observations of the GPS satellite signals yield very accurate three-dimensional relative position data. Baselines of up to 100 km are routinely measured to accuracies of 1 cm to 5 cm rms. Differential ellipsoid height accuracies at the few centimeter level have been achieved; depending on accuracies of geoidal undulations, useful elevation differences can be computed. This paper focuses on the more mundane activities required to obtain such results. Although GPS satellite surveying employs sophisticated methodology and instrumentation, there are many practical aspects to be considered. These include requirements for ties to existing control, station selection criteria, field procedures, data handling and storage, and processing steps.
Some Recommendations for Improving Two-Color Distancers
Authors: Chiyu Liu
Published: July 2019

In the early 1970s, the two-color distance measuring instrument came into being, but it has developed very slowly. According to my research, it is possible that the following improvements in its design will help to accelerate the development of this instrument.
Trends in Land Registration
Authors: McLaughlin John D. , Williamson Ian P.
Published: July 2019

This is the first of two articles written to review the new Land Titles Act in the Province of New Brunswick. The primary objective of this article is to review current trends and reform in land registration systems, with particular emphasis on Canada and Australia. The objectives of land registration are discussed. Such topics as automated titles, the completion of the register, cadastral mapping and boundaries, possessory rights, institutional reform, and reform of deeds registration systems are discussed. The article emphasizes the importance of the equality of the legal and survey component in a successful land registration system.
A Review of the Recent New Brunswick Land Titles Act
Authors: Williamson Ian P. , McLaughlin John D.
Published: July 2019

This is the second of two papers examining the new Land Titles Act in New Brunswick. The first paper reviewed trends and developments in land registration systems against which this legislation has been measured. This paper describes the new act in general and makes a critical review of various aspects. The review concentrates mainly on administrative and technical issues with particular emphasis on surveying and mapping. In recognition that the new legislation cannot be examined in isolation, the existing conveyancing and deeds registration system is briefly described, as is the existing cadastral survey system and the operation of the Land Registration and Information Service (LRIS) in the province.
Reference Ellipsoid Misalignment, Deflection Components and Geodetic Azimuth
Authors: Vaníček Petr , Carrera Galo
Published: July 2019

Whichever way the geodetic reference ellipsoid, used as a horizontal datum, is oriented within the earth it is theoretically never exactly aligned with the geocentric coordinate system (called here Conventional Terrestrial System). It is then important to know just how much the misalignment affects the pertinent geodetic quantities in the horizontal geodetic network: the azimuth and the deflection components. The misalignment effect on these geodetic quantities must be accounted for to maintain the consistency of all the involved coordinate systems and transformations between them.