Journal of Surveying Engineering

A global positioning system (GPS) geodetic network has been established at the western end of the North Anatolian Fault Zone (NAFZ) in the Marmara Sea Region (Turkey) with a density of 47 points to determine the velocity field. Some attention is paid to the determination and testing procedures. This study focuses on the purpose of determining methods of crustal movements with GPS, deformation analysis, the reliability of conclusions, and the character of the deforming area. Displacements are determined by using the method of S-transformation. The analysis of the deformation field was performed both in two and three dimensions. Testing procedures for deformation measurements are derived. Subsequently rotation and translation of the objects are studied. The results of the proposed test methods are independent of the coordinate system chosen. Two large earthquakes on the region with magnitudes of 7.4 and 7.2 in 1999 show the importance of such studies to submit references to other scientists.

Analysis of an exceptionally long and homogeneous geodetic monitoring record of a deep-seated, slow $(15\mathrm{cm}/\mathrm{year})$ moving landslide indicates that changes in the distance between a survey point lying on stable ground and several control points lying on slipping ground have effectively and accurately detected and recorded dislocations of the control points exceeding the value of a few millimeters; a result confirmed by independent, submillimeter-accuracy spirit leveling data. Landslide monitoring based on radial length changes permits estimation of the velocity and of the acceleration of the landslide movement, and is free of various disadvantages characterizing other geodetic techniques (delayed results, high cost, need for accessibility of control points, etc.). This method can therefore be used to provide near-real time, efficient, low cost, and reliable monitoring for many landslides and other deforming bodies at a few millimeter accuracy. It may also be combined with modern telemetric or robotic survey systems to provide real-time and automated deformation monitoring.

Normal curvatures formed at a point on any surface and relations regarding these are analogous to the deformations formed on distorted surfaces. By using the analogy, which is mentioned for the first time in this paper, graphic methods are given to find normal section curvatures from principal curvatures formed at one point on the rotational ellipsoid surface or to find principal curvatures and principal direction from normal curvatures. In addition, it is mentioned that these methods are valid for all types of surfaces. Then some interpretations are given regarding the different situations in finding the normal curvatures, which are formed on the various surfaces by the graphic method. In the application section, results are obtained by applying the given graphic method at a point on the surface of the rotational ellipsoid, and these results are compared with those from the analytic method.

The paper tries to apply the Butterworth low-pass filter to inertial navigation system (INS) data processing. A set of INS heading data of a practical example has been calculated and the filtering tested. This filtering method is used to examine the correction of the results made by Guo and Wang. Based on the discrete Fourier transformation and the digital filter design technique, a Butterworth low-pass digital filter has been designed and performed to process INS heading raw data. The design of a special Butterworth filter includes determination of the technical specification of the filter and of the response function in the time domain or the frequency domain (determination of the order and cutoff frequency of the digital filter). For the high-frequency noise of INS raw data, a Butterworth low-pass filter has been designed to obtain a more accurate INS heading. The choice of the parameters and orders of the filter is also discussed in the paper. Finally, an example of INS heading data calculation is presented. The signal-processing TOOLBOX of MATLAB software is used for calculating and mapping the results. The result (RMS) is at the level of 0.01°. The method described here is simpler than Kalman filtering or the smoothing method and has sufficient accuracy for INS processing. It also provides ideas for some other series of raw data with high-frequency noise.

Precise heighting by the hidden point bar method is investigated. The investigation includes development of the mathematical model, calibration of the hidden point bar, and comparison with precise leveling and precise trig heighting. The method is applied in the field at a coal-fired electric power generating plan. Both the field application and the comparison with precise leveling and precise trig heighting indicated that the level of precision is on the order of $0.1\mathrm{mm}$. Special advantages of the method are that the target point does not have to be visible from the measurement instrument and the bar placed on the target can be set at any convenient orientation.

Economic considerations are one of the most fundamental elements affecting the standards of highway projects. Therefore, cut-fill balancing and minimizing the amount of earthwork are significant factors that can decrease construction costs. In order to achieve this, the “weighted ground line method,” which describes a hypothetical ground line that guides cut-fill balancing and minimizes the total amount of earthwork, is presented. The main idea of this approach is to find a “hypothetical reference line” (instead of a ground line) that makes the earthwork optimization possible in terms of cut-fill balancing as well as earthwork minimization. Because the centerline ground elevation rarely represents the transverse changes in the ground elevations of a cross section (template), setting the grade line as close as possible to the ground line may be misleading in terms of optimizing earthwork. Another point to be considered is that all the excavated (cut) material may not be used as a fill material due to the difference between the original volume in a cut and the volume in a fill after compaction. Furthermore, all excavated material may not be suitable for fill. In this respect, to be able to accomplish the exact cut-fill balance and minimize the total amount of earthwork, these two factors must be taken into consideration. For this reason, modified cut and fill volumes should be used for calculating weighted ground elevations. Consequently, the aim of this paper is to balance the cut-fill volume and minimize the amount of earthwork while considering shrinkage and swell factors, thereby achieving much more cost-effective results.