Understanding Survey Distances

Surveys can be reviewed and analyzed based on varying ways of recording and measuring distances. The following are definitions and descriptions of the different measurement and recording terms used with PCS Survey Manager:

• Measure— the measured distance between the current data point and the starting location of the survey, calculated using the GPS coordinates of the data points. The measure represents the distance between the two points along a straight line, not the distance along the survey route.

• Engineering Station — a known location that can be tied to a specific data point. Adding engineering stations to multiple data points allows you to shift, stretch, or shrink sections of the survey so the data points line up with known locations along the survey.

  If you select Eng. Station for the Chart Legend and Axis Basis sections the Chart display options, the value that shows in the legend or serves as the x-axis range will be either the Eng Station - Measure or the Eng Station - Chainage value, depending on the option chosen in the Eng. Station Calculation section.

• Eng Station - Chainage — the distance between the current data point and the starting location of the survey segment, adjusted based on nearby engineering stations. The Eng Station - Chainage field takes the Segment Chainage field's value and modifies the value so it will fit between the surrounding engineering stations.

• Eng Station - Measure— the measured distance between the current data point and the starting location of the survey, adjusted based on nearby engineering stations. The Eng Station - Measure field takes the Measured field's value and modifies the value so it will fit between the surrounding engineering stations.

• Segment Chainage — the distance along the survey route between the starting location of the survey segment and the current data point. The segment chainage value comes from the original survey segment file.

• Station Number — the distance along the survey route between the starting location of the overall survey and the current data point. A data point's station number is dependent on its survey segment's position in the overall survey and is calculated by combining the current data point's segment chainage with the station number of the last data point in the previous survey segment. The first data point in the overall survey has a station number of 0.