טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
M.Sc Thesis
M.Sc StudentMaklada Rabia
SubjectElectromagnetic Interferences Effect on GPS Receivers and
Total Stations
DepartmentDepartment of Civil and Environmental Engineering
Supervisor Professor Gilad Even-Tzur
Full Thesis text - in Hebrew Full thesis text - Hebrew Version


Abstract

The potential for degraded performance of electronic measuring instruments such as GPS and Total Station (TS) when they are used near electric power facilities was investigated.

Electromagnetic interferences (EMI) from power lines are caused by two phenomena: Corona, and spark discharges. In both of the above cases, electromagnetic "noise" fields are created, and which are liable to cause failures in the performance of electronic measuring devices.

The present research's goal was to carry out a thorough examination of the effect of the electromagnetic field on electronic measuring instruments such as GPS and TS.

Two field experiments were carried out in two separate locations of the electric company in which a particularly high electromagnetic field exists.

In order to examine the reliability of the results obtained from the electronic measuring instruments, a steel tape measuring were used. These measurements constituted the basis for comparing the results obtained from the electronic measuring instruments.

Five points were established on the ground at the "Kishon" power station. The distances between the five points were measured with the use of a steel tape, two different TS instruments, and three different GPS receivers. A comparison between the distances resulting from measuring with the GPS receivers, the TS instruments, and the steel tape measurements, showed that it was unlikely that the EMI were the cause of the failure in the performance of the GPS receivers and TS instruments.

Two sub-experiments were carried out at the "Zevulun" substation: GPS measurements at the point inside a 400kV high voltage pole and GPS measurements at points stationed under the 400kV high voltage line.

The results obtained from the GPS measurements to the point inside the 400kV high power voltage pole showed that the results did not satisfy the necessary accuracy criterion.

The results of the comparison between the distances with GPS measurements and the distances with a steel tape measurer showed that it was unlikely that EMI created from the 400kV high voltage line caused the failure in the GPS receivers' performance.

The reason for the low quality of the solutions obtained from the GPS measurements inside the 400kV high voltage pole as opposed to the high quality of the solutions obtained from the measurements beneath the 400kV high voltage line were a result of high multipath and cycle slips, which were caused by the complicated structure of the pole.