الفهرس 
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Abstract
Nowadays, precise distance measurement plays an important role in surveying, construction and advanced engineering such as aircraft assembly, space missions, and geodetic applications.
Laser-based Electronic Distance Meters (EDMs) and distance meters that are based on Global navigation satellite systems (GNSS) receivers have become the major technologies utilized in most surveying and construction applications with millimeter-scale accuracies.
EDMs are the ideal choice to accurately measure the distance to an object while avoiding any contact measurement such as those conducted by bulky reel-in tapes or walking wheels. Additionally, EDMs can be used to measure large surfaces and volumes.
On the other hand, distance meter that are based on GNSS technologies are the primary tool not only for precision surveying but also for geodesy, geophysics, and many other industrial applications worldwide.
Rapid developments in these fields bring more and more requirements in their accuracy assessment. Since, the only way to assure the accuracy of these instruments’ measurements is by calibration. In order to calibrate an instrument, a method with a superior accuracy is required. Since the accuracy of the GNSS distance meters is in the centimeter range, they can be calibrated using a calibrated EDM with accuracy in the millimeter range. For the calibration of EDMs, a method with a sub-millimeter accuracy is required. In addition, the calibration must be traceable to the SI unit of length, i.e., the meter. In order to facilitate such calibration chain, it is performed through a baseline, in such a way that, the distances between the bases of the baseline are accurately measured using the reference technique; then the calibrated distances of the baseline are used for calibration of the device under-calibration.
In this thesis, a baseline is constructed at NIS campus over 300 m to be used as a transfer standard for the calibration of GNSS-based distance meters. The inter-pillar distances of this baseline is measured using a calibrated EDM. For the calibration of this EDM, an optical method with accuracy in the sub-millimeter range is required. An investigation is performed over several optical methods to find the suitable method that offers the submillimeter precision. The optical techniques considered in this thesis are: the time-of-flight (TOF), Phase-Shift of Amplitude Modulated signal (PS-AM), Frequency Modulation of Continuous Wave (FMCW), and Opto-Electronic Oscillator (OEO). These techniques were discussed and experimentally demonstrated throughout the thesis in order to establish a reference absolute distance measuring system for EDMs calibration. In the thesis we succeeded to establish a 1550 nm reference optical system based on off-the-shelf components using the optoelectronic oscillator (OEO) with a submillimeter accuracy, which is used for calibration of an indoor baseline and consequently the calibration of an EDM.
In addition, determination of the absolute position on earth using GNSS technologies plays a vital role in navigation in land, sea or in the air. Moreover, it is used for mapping the location of power plants or the location of the offshore gas and oil platforms. It can be also used for the guidance of the unmanned systems that are used in military applications. Calibration of GNSS-based position determination receivers is vital for their accurate operation. Therefore, another baseline is constructed in NIS campus for the calibration of the GNSS-based location receivers.
By doing this, a complete solution is provided for the calibration of the distance measurement equipment that are used in surveying and construction.