The error due to bad ranging is cumulative; positive.

Bad ranging refers to errors that occur in the measurement of distances or ranges. These errors can arise due to various factors such as equipment limitations, environmental conditions, and human errors. The error due to bad ranging is cumulative, meaning that it accumulates over multiple measurements and increases the overall uncertainty in the final result. In addition, the error is predominantly positive, meaning that the measured values tend to be higher than the true values.

Explanation:

1. Cumulative nature of the error:
- When ranging errors occur, they affect each individual measurement of distance.
- These errors can add up or accumulate over multiple measurements, leading to a larger overall error in the final result.
- For example, if the true distance between two points is 100 meters, but each individual measurement has a ranging error of 2 meters, the accumulated error after 10 measurements would be 20 meters.
- This cumulative nature of the error means that the more measurements are taken, the greater the overall error becomes.

2. Positive nature of the error:
- Bad ranging errors tend to be predominantly positive, meaning that the measured values are generally higher than the true values.
- This positive bias can be caused by various factors such as instrument calibration issues, signal reflections, or systematic errors in the measurement process.
- For example, if a measuring instrument consistently overestimates distances by 1 meter, all the measured distances will be systematically higher than the true distances.
- This positive bias can lead to inaccurate calculations and decisions based on the measured values.

Conclusion:

In summary, the error due to bad ranging is cumulative and predominantly positive. It accumulates over multiple measurements and tends to result in measured values that are higher than the true values. It is important to consider and account for these errors when conducting distance measurements in civil engineering projects to ensure accurate and reliable results.