ADVANCED TOPICS IN SURVEYING

INTRODUCTION

Photogrammetry  – Introduction

– Terrestial and aerial Photographs

–  Stereoscopy

– Parallax

– Electromagnetic distance measurement

– Carrier waves

–  Principles – Instruments

– Trilateration

Hydrographic Surveying

– Tides

– MSL

– Sounding methods

–  Location of soundings and methods

– Three point problem

– Strength of fix

– Sextants and station pointer

– River surveys

– Measurement of current and discharge

Cartography

–  Cartographic concepts and techniques

–  Cadastral  surveying

–  Definition

–  Uses

–  Legal values

–  Scales and accuracies.

PHOTOGRAMMETRIC SURVEYING

Photogram metric surveying or photogrammetry is the science and art of obtaining accurate measurements by use of photographs, for various purposes such as the construction of planimetric and topographic maps, classification of soils, interpretation of geology, acquisition of military intelligence and the preparation of composite pictures of the ground.

PRINCIPLES BEHIND TERRESTRIAL PHOTOGRAMMETRY.

The principle of terrestrial photogrammetry was improved upon and perfected by Capt. Deville, then Surveyor General of Canada in 1888. In terrestrial photogrammetry, photographs are taken with the camera supported on the ground. The photographs are taken by means of a photo theodolite which is a combination of a camera and a theodolite. Maps are then compiled from the photographs.