Measuring Principles
Although there are many EDM instruments available, there are basically only two methods of measurement employed, namely the pulse method and the more popular phase difference method. Pulse method A…
Main Engine Layout Familiarization – B&W Engine Room Layout
The ship’s engine room watch-keeping engineer must be familiar with main engine layouts, including their components optimum operating pressures and temperatures. This familiarization should include a B&W engine room layout,…
Field surveying
Introduction This chapter is designed to introduce you to the various surveying techniques used to obtain the original field data on which such maps are based. An understanding of these…
Distance Adjustment
To eliminate or minimize the systematic errors of taping, it is necessary to adjust each measured bay to its final horizontal equivalent as follows. Standardization During a period of use,…
Distance measurement
Distance is one of the fundamental measurements in surveying. Although frequently measured as a spatial distance (sloping distance) in three-dimensional space, usually it is the horizontal component which is required.…
EQUIPMENT
The equipment used in the levelling process comprises optical levels and graduated staffs. Basically, the optical level consists of a telescope fitted with a spirit bubble or automatic compensator to…
Bench mark (BM)
In order to make OD accessible to all users throughout the country, a series of permanent marks were established, called bench marks. The height of these marks relative to OD…
Vertical control
INTRODUCTION This chapter describes the various heighting procedures used to obtain the elevation of points of interest above or below a reference datum. The most commonly used reference datum is…
Basic concept of errors
The basic concept of errors in the data captured by the surveyor may be likened to target shooting. In the first instance, let us assume that a skilled marksman used…
Errors In Measurement
It should now be apparent that position fixing simply involves the measurement of angles and distance. However, all measurements, no matter how carefully executed, will contain error, and so the…
