## 4. Error Sources and Behavior

### a. Instrumental / Personal

#### (1) Consistency

##### (a) Principle

It may take some time for a new surveyor to settle into a comfortable, consistent walking rate.

Random

##### (c) Compensation

Practice and paying attention to other errors

#### (2) Footgear

##### (a) Principle

Shoe type, Figure B-4, affects how a person walks.

 Figure B-4Footgear

Random.

##### (c) Compensation

Use footgear typically worn in field situations.

#### (3) Counting

##### (a) Principle

Forgetting the count as you are pacing can happen, particularly on longer distances.

Mistake.

##### (c) Compensation

Repeat measurements to find and discard mistaken counts.

#### (4) Individual v Group

##### (a) Principle

Everyone has their own normal stride. When walking in a group, some individuals speed up, others slow down so the group stays together. This happens subconsciously and will affect pacing.

Random.

Walk alone.

#### (5) Self-consciousness

##### (a) Principle

The key to successful pacing is to maintain a normal comfortable walking rate. Doing something out of the ordinary will affect pacing.

Step off normally when stating a pace (many first-timers exaggerate the initial step).

Don't look down at your feet (you won't leave them behind), instead watch where you're going and to see obstacles.

Use peripheral vision at the end of the pace to avoid stretching or shrinking the last step.

Believe it or not, some people still remember and react to "Step on a crack, break your mother's back." (If you didn't before, you will now as I've planted the seed)

Random.

Practice.

#### (6) Computations

##### (b) Principle and Behavior

Over/understating accuracy, math blunder, etc. Mistake.

Care and review.

### b. Natural

#### (1) Terrain

##### (a) Principle

In Surveying we use horizontal distances; pacing returns a distance along the ground, Figure B-5. On rolling terrain, the paced distance will be too long.

 Figure B-5Pacing Along the Ground

Random.

##### (c) Compensation

The only way to compensate is to make an adjustment based on terrain analysis.

#### (2) Slopes

##### (a) Principle

Slopes affect walking rate. Going uphill tends to shorten paces, downhill lengthens, Figure  B-6.

 Figure B-6Slope Effects
##### (b) Behavior

Systematic/Random.

##### (c) Compensation

The only way to compensate is to make an adjustment based on terrain analysis.

#### (3) Temperature

##### (a) Principle

We tend to walk more quickly in cold weather than warm which affects pace lengths.

Random.

##### (c) Compensation

Re-calibrate under cold conditions.