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Software - Field Book Data to Reduced Level Conversion



Field Book or Level Book Calculations are carried out on the readings noted during a Survey Operation called Levelling. We will first understand Levelling process in detail and then we will look at how to calculate reduced level in Field book.

Levelling:

Levelling is a means by which you can determine the elevation of points, using other known points as references. Here are definitions for some commonly used terms related to Levelling and basic surveying:

Terms & Definitions

Sl.No. Term Definition
1 Datum An assigned or assumed reference level surface A reference surface to which the heights of all points in a survey or on a site are referred May be arbitrary or a national height datum
2 Mean Sea Level  (MSL) Most regularly used datum
3 Benchmark A permanent or semi-permanent physical location of known or assigned elevation Usually used as the starting and finishing point for levelling
4 Temporary Bench Mark (TBM) A point placed (e.g. peg, nail, spike) to provide a temporary reference point
5 Back Sight  or Back shot (BS) A sighting with a level back to a point of known elevation
6 Fore Sight or Fore shot (FS) A sighting with a level to determine the elevation of a point
7 Change Point or Turning Point A point at which you have established an elevation with FS and on which you will subsequently take a BS Change points should be… Stable Well defined Recoverable (e.g. sharp rock, nail, change plate, etc…)
8 Intermediate Site or Intermediate Shot A fore shot to a point at which you want to know the elevation but which will not be used as a turning point
9 Reduced Level (R.L.) or Elevation The height of a point above the selected datum.
10 Height of Instrument (HI) or Elevation of Instrument (EI) The vertical distance from datum to line of sight of the instrument

Levelling Finds application in following assignments

  • To determine Point heights (relative to a datum)
  • Height differences between two points (independent of datum)
  • Creating longitudinal sections and cross sections
  • Contouring
  • Setting out

Levelling Calculation can be done in two ways

  1. Rise and Fall Method
  2. Height of Collimation Method
 
Sl.No. BS IS FS RISE FALL RL RISE-FALL Calculation RL Calculation
1 2.191 0 0 0 0 49.873 Previous BS + Previous IS - IS - FS Previous RL +Rise - Fall
2 0 2.505 0 0 0.314 49.739 2.191+0-0-2.505 49.873+0-0.314
3 0 2.325 0 0.18 0 49.739 0+2.505-2.325-0 49.559+0.18-0
4 3.019 0 1.496 0.829 0 50.568 0+2.325-0-1.496 49.739+0.829-0
5 0 2.513 0 0.506 0 51.074 3.019+0-2.513-0 50.568+0.506-0
6 1.752 0 2.811 0 0.298 50.776 0+2.513-0-2.811 51.074+0-0.298
7 0 0 3.824 0 2.072 48.704 1.752+0-0-3.824 50.776+0-2.072
 
Sl.No. BS IS FS HI RL HI Calculation RL Calculation
1 2.191 00 00 52.064 49.873 Previous HI + BS - FS HI -IS - FS
2 00 2.505 00 52.064 49.559 52.064+0-0 52.064-0-2.505
3 00 2.325 00 52.064 49.739 52.064+0-0 52.064-0-2.325
4 3.019 00 1.496 53.587 50.568 52.064+3.019-1.496 53.587-3.019-0
5 00 2.513 00 53.587 51.074 52.064+0-0 53.587-0-2.513
6 1.752 00 2.811 52.528 50.776 52.064+1.752-2.811 52.528-0-1.752
7 00 00 3.824 48.704 48.704 52.064+0-0 48.704-0-0

How to do Field Book / Level Book Calculations?

Install Field Book Application developed by ESurveying. This Field book Calculation utility is developed considering levelling of cross section data. Double click on Field Book Icon We can do following type of calculations using this application
  1. Convert Raw Field book Excel Sheet to Field book Sheet with Reduced level
  2. Convert Raw Field book Excel Sheet to Excel Sheet which represents Cross Section Data
  3. Convert Excel Sheet with Cross Section Data into Field book Sheet

Convert Raw Field book Excel Sheet to Field book Sheet with Reduced level

Click on ‘FB Template’ and fill all your field book / level book data in that excel sheet and save it. Select Saved Excel File, by clicking on ‘…’ next to Select File Textbox. Click on ‘Export’ to get the Excel Sheet with Calculated Reduced level

Convert Raw Field Book Excel Sheet to Excel Sheet with Reduced Levels

Click on ‘FB Template’ and fill all your field book / level book data in that excel sheet and save it. Select ‘Field Book’ from Input and Select ‘ESurvey Section Excel Format’ from output Group. Select Saved Excel File, by clicking on ‘…’ next to Select File Textbox. Click on ‘Export’ to get the Excel Sheet with Calculated Reduced level in Cross Section data format. Note: you have to mention the Cross Section number in 2nd Column and Distance in 8th Column

Convert Excel Sheet with Cross Section Data into Field book Sheet

Click on ‘ES Template’ and fill all your cross section data in that excel sheet and save it. Select ‘ESurvey Section Excel Format’ from Input and Select ‘Field Book’ from output Group. Select Saved Excel File, by clicking on ‘…’ next to Select File Textbox. Enter the required fields
  1. 'Staff Minimum Height’ and ‘Staff Maximum Height’ – Staff Height that you use in Field Example: 3 M, 5 M
  2. ‘Instrument Proximity’ – Distance that your instrument can measure Example: 20 M – 100 M
  3. ‘Starting RL’ – By referring to cross section data you can specify this value – Say ’98.5’ M
  4. ‘Rounding’- Select Precision of your Instrument – Example: 0.005 – 0.10
Click on ‘Export’ to get the Excel Sheet with Cross Section data represented as Field book data with random Back Sight, Fore Sight, collimation Level Etc. This option is used to represent the survey data done in total station as Levelling procedure.

Click the Link below to Download.

Access this URL[FieldBook.exe-Download]