MODULE 10: Omitted Measurements

OMITTED MEASUREMENTS

• When it is not always possible or practical to determine by field observation all lengths/distances and direction of line(s) within a closed traverse.

• Missing quantities may be determined analytically to complete data for the traverse.

• Maximum of two omitted measurements.

• The practice of omitted measurement is NOT desirable and should be avoided, but maybe used to advantage in certain instances.

  e.g.,

  • dividing large tracts of lands into specific parts or required areas

  • determining interior lot lines

  • presence of obstacles, rugged terrain in site surveyed

  • unfriendly/hostile environment

  • lack of time to complete the survey

Omitted measurements

It eliminates the check on the precision of the field measurements that were made. There is no choice but to assume that the measurements taken are all correct and without error in order that the missing quantities may be calculated

Cases of omitted measurements

• Omitted measurements are in one side

• Omitted measurements involving two adjoining sides

• Omitted measurements involving two non-adjoining sides

1. Omitted measurements are in one side

• Length and bearing of one side unknown

• Unknown length and bearing

2. Omitted measurements involving two adjoining sides

• CASE 1: Length of one side and bearing of another side unknown

• CASE 2: Lengths of two sides unknown

• CASE 3: Bearings of two sides unknown

3. Omitted measurements involving two non-adjoining sides

• CASE 1: Length of one side and bearing of another side unknown

• CASE 2: Lengths of two sides unknown

• CASE 3: Bearings of two sides unknown

PRINCIPLES TO BE APLIED:

• A line may be moved from one location to a second location parallel with the first, and its latitude and departure will remain unchanged

• The algebraic sum of the latitudes and the algebraic sum of the departures of any system of lines forming a closed figure must be zero, regardless of the order in which the lines are placed