GPS Practical Field Guide For Surveyors

In Finland the government organisation National Land Survey of Finland (later NLS) is responsible of land survey, cadastral survey and national mapping. Hereby NLS has a long history in using different methods of measurements in all sectors of surveying. However, the use of GPS was not extensively implemented until the year 2000. Before 2000 GPS was used mainly in geodetic survey. Since then the development of using GPS has been rapid.

In Algeria Today, GPS technique is used in various applications such as cadastre, conducting road project, auscultation, bathymetry survey, and deformation monitoring. Algerian surveyors confront a major problem about transformation from GPS co-ordinates to national one, and seek about GPS guidelines to help them in their GPS operation field and processing. Generally, they used instructions given by GPS receiver manufacturer as guidelines to start and perform their own project. In this context, a need to develop a set of specifications and recommendations to use GPS for the above specific applications is considered an urgent task. In this paper is discussed some guidelines and recommendations limited only on large-scale applications such as cadastre, and based essentially on our GPS experience. This experience is based on several projects developed at the Geodetic Laboratory of the National Center of Spatial Techniques, about the use of GPS in cadastre, networks engineering, auscultation, road survey, and in the south of Algeria (lack of geodetic information). These guidelines concern the following subjects: planning and conducting a GPS project for cadastral survey; conception of a new cadastral network and how to update and densify an existing cadastral network; adequate positioning mode; testing and calibration of GPS receivers; field and office procedures; results checking and presentation.

2005

Conventional methods of surveying and navigation require tedious field and astronomical observations for deriving positional and directional information. Rapid advancement in higher frequency signal transmission and precise clock signals along with advanced satellite technology have led to the development of Global Positioning System (GPS). The outcome of a typical GPS survey includes geocentric position accurate to 10 m and relative positions between receiver locations to centimeter level or better. Technological aspect as well as applications of GPS in various fields are discussed in this paper.

Today advanced Surveying techniques are improving accuracy of measurements of distance, height, area and positional information of an area. Total station is an advanced instrument which is mainly used for measuring horizontal distance, slope distance, remote objects height and area of a land parcel now a days this instrument is majorly used for determining the land area information. The objectives of this thesis is to evaluate and compare accuracy and time expenditure of conventional methods like Chain, Tape, Plane Table and Theodolite with Total Station (TS) and Global positioning system (GPS).by Comparing the accuracy and the required time of these measurements will improve the knowledge about how much the precision and accuracy can be achieved by advanced instruments and at which time expense. It is possible to conduct survey with less man power and less time while using Total station. In the Campus of Karpagam Academy of Higher Education (KAHE) football ground was taken as study area. The aim of the study is to compare the land survey results conducted by conventional methods with Total Station and GPS. The study area was measured using conventional methods like Chain, Tape, Plane Table and theodolite Total Station (TS) and Global positioning system (GPS). The collected data was processed in AUTO CAD and terrasync. The results were compared and analyzed. The campus will be measured using total station. Finally the plots are represented separately with the scale and area information.

مجلة مرکز البحوث الجغرافیة والکارتوجرافیة, 2020