What kind of measurement method is generally used in elevation measurement?

The method used in pipeline elevation control survey is determined according to the main purpose. At present, there are three main methods of elevation control survey:

1, leveling

2, trigonometric leveling

3.GPS height measurement.

operation sequence/order

1, the principle of elevation control point layout

(1) height system in the survey area shall adopt the national elevation datum. When surveying in areas with existing elevation control network, the original height system can be used. When it is difficult to connect small measuring areas, the assumed height system can also be used.

(2) The methods of elevation measurement include leveling method, electromagnetic wave ranging trigonometric leveling method. Common leveling methods.

(3) Grade division of elevation control survey: Grade II, III, IV and V in turn. According to the need, each grade can be used as the first level elevation control of the survey area.

2. Layout method of elevation control points

(1) Main technical requirements of leveling method:

Level markers shall be buried at all levels of leveling points. Benchmarks should be selected in places with hard soil to facilitate long-term maintenance and use. Wall leveling points should be selected on stable buildings, and the points should be easy to find and conform to the regulations.

A survey area and its surroundings should have at least 3 leveling points. The distance between leveling points should comply with the regulations.

Leveling observation should be carried out after the monument is buried. When the height difference between the two observations is greater than the limit, it should be re-measured. When the retest results are compared with the original test results respectively, and the difference does not exceed the time limit, the average of the three results should be taken.

(2) During equipment installation, attention should be paid to measurement: it is best to use a leveling point as the starting point of elevation. When the workshop is large, leveling points can be added, but the observation accuracy should be improved.

(3) The included angle between the apparent axis of the level and the axis of the leveling tube shall comply with the regulations. The difference between the average length of the meter interval on the leveling ruler and the nominal length shall comply with the regulations.