Chapter 8. Electronic Survey Measurement. Dr. Maher A. El-Hallaq Lecturer of Surveying The Islamic University of Gaza

Transcription

1 Chapter 8 Electronic Survey Measurement Dr. Maher A. El-Hallaq Lecturer of Surveying The Islamic University of Gaza

2 Contents Introduction. Parts of a total station. Handling a total station. Total station set up. Coordinate calculation. Total station field techniques. Field procedure.

3 Introduction Transits and theodolites were commonly used. Recently, total stations has replaced all instruments. Total station can accomplish all tasks much more efficiently. In addition, they can also measure distances accurately and quickly. Furthermore, they can make computations with angle and distance measurements. They can display the results in a real time. They are used for all types of surveys.

4 Introduction Total station = theodolite + built in EDM + built in data collector + microprocessor

5 Introduction Measures and Records: Horizontal Angles Vertical Angles and Slope Distances Calculates: Horizontal Distance Vertical Distance Azimuths of Lines X,Y,Z Coordinates Layout etc.

6 Parts of a total station

7 Parts of a total station

8 Parts of a total station

9 Parts of a total station

10 Parts of a total station 1. The telescope. 2. The angle measurement system. 3. The vertical circle. 4. Rotation of the telescope. 5. The base of a total station. 6. The tribrach.

11 Parts of a total station 7. An optical plummet. 8. A tripod. 9. The microprocessor. 10. The keyboard and display. 11. The communication ports.

12 Handling a total station

13 Total station set up Should be centered over the survey point. Should be leveled. - bull s-eye bubble for preliminary leveling - one plate bubble for precise leveling

14 Total station set up

15 Vertical coordinate z v h B = h A + HI + S sin v - HT

16 Horizontal Coordinate (x,y) x k = x i +d ik sin α ik y k = y i +d ik cos α ik

17 Total station field techniques 1. Point Location

18 Total station field techniques 2. Missing Line Measurement

19 Total station field techniques 3. Resection

20 Total station field techniques 4. Azimuth Calculation

21 Total station field techniques 5. Remote Object Elevation Calculation

22 Total station field techniques 6. Offset Measurement

23 Total station field techniques 7. Setting Out Positions

24 Total station field techniques 8. Area Computation

25 Summary of typical total station characteristics Parameter Input 1. Angle units: degrees 2. Distance units: meters 3. Pressure units 4. Temperature units 5. Prism constant (usually 0.03 m) 6. Automatic point number increments

26 Summary of typical total station characteristics Parameter Input 7. Height of instrument (HI) 8. Height of reflector (HR) 9. Point number and code number of occupied and sighted stations 10. Date and time setting

27 Summary of typical total station characteristics Capabilities 1. Monitor: battery status, axes status, collimation, etc 2. Compute coordinates: easting, northing, elevation 3. Traverse closure and adjustment and areas 4. Topography reduction 5. Object heights ROE 6. Missing line measurement 7. inversing

28 Summary of typical total station characteristics Capabilities 8. Resection 9. Layout (setting out) 10. H and V collimation correction 11. Load external programs 12. Transfer data to the computer (download) 13. Transfer files to the data collector (upload)

29 Field Procedure for total station Initial Data Entry 1. Project description 2. Date and crew 3. Temperature and pressure 4. Prism constant 5. Curvature and refraction settings 6. Number of measurement repetitions (angle or dist.) 7. Choice of imperial units for all data (ex: SI)

30 Field Procedure for total station Survey Station Descriptors

31 Field Procedure for total station Occupied Point Data Entry 1. Height of the Instrument 2. Station Number 3. Station Identification code 4. Coordinates of occupied station 5. Coordinates of backsight (BS) station 6. Description point data

32 Field Procedure for total station Sighted Point Data Entry 1. Height of prism (reflector) HR 2. Station Number 3. Station Identification code 4. Description point data

33 Field Procedure for total station Example

34 Automatic Target Recognition

35 THANK YOU Questions