SURPAC Surveying Software
An underground Peg Calculation using the Double Button Method
Underground Peg Calculation using the "Double Button" Method
This application is designed to solve the common underground Mine Survey problem of determining and checking the [Y, X, Z] (or [E, N, Z]) ordinates a new Peg. 

The [Y, X, Z] (or [E, N, Z]) ordinates of both the Set Up Peg and the Back Sight peg must be known, and exist in the current Coordinate File. 

Although not as secure as the previously described "Double Set Up" technique, this technique does provide a "semicheck" on the distance between the two Pegs, and their relative elevations. Until the Peg's position is verified by means of a closed traverse at some future date, its absolute position can not be assured. 

The required method of Survey is a Set up at the Set Up (or Fixing) Peg. 

At the Set Up Peg , the following quantities should be measured or observed :


The application allows for data entry by :


Calculation will only take place if none of the angular and/ or linear measurements exceeds the User specified limits. These limits are compared to the calculated differences for Vertical Angles, Horizontal Angles, Horizontal Distances and Vertical Height Differences. They also provide the option of forcing the User to carry out a Back Check before the new Fore Sight Peg can be calculated. The ability to modify these limits is limited to Users having the necessary Security Code. This Security Code prevents unauthorized Users from changing the limits, or resetting the Back Check option. 

Before the New Peg calculation takes place, a Back Check calculation may be carried out to verify the relative positions of the Back Sight Peg and the Set Up Peg against the theoretical values. 

After calculation takes place, the Coordinates, Peg Elevation and Floor Elevation of the Fore Sight Peg (New Peg) will be stored in the current Coordinate File. 

The results of the Peg calculation will also be stored in the MultiPolar/Peg File of the current Coordinate File. This file will hold and display up to 4 determinations of a Peg, over and above the actual coordinates (current values) stored in the Coordinate File. Running the Edit a MultiPolar/Peg File (found under the General main Menu) programme will generate a display of a summary of all determinations of existing Pegs in the Coordinate File. The stored ASCII Peg File (type ***.pg2) can then be called, for any the Point/Peg determinations, which will in turn generate a full display of all the observational and derived data for the New Peg calculation. 

After calculating the New Peg, an ASCII Peg File (type ***.pg2) of all observed and derived data my be created. This ASCII file has four main uses :


The application also allows for the calculation of a Chain length at the New Peg. The Chain length is the height difference between the Peg elevation of the New Peg and a computed Grade Elevation, based on User input information. 

The
option to Print the results is available, after the on screen entries have been made and
checked and the New Peg calculated. The results of both the Back Check
calculation and the Chain Length calculation may also be printed. 