What Is an Azimuth Compass?

The azimuth angle refers to the satellite receiving antenna that rotates from 0 ° to 360 ° in the horizontal plane. When the azimuth is adjusted, the parabola moves left and right in the horizontal plane. Generally, the results obtained by calculation software or in the data should be based on the north direction (about the geomagnetic south pole) as the standard, and the satellite antenna's pointing east or west should be adjusted by an angle, which is the so-called azimuth.

The azimuth is the horizontal angle from the north direction line of a point in a clockwise direction to the target direction line, and it is expressed by "degree" and "close position". Commonly used to determine orientation, indicate the target and maintain the direction of travel. From

Azimuth

Since each point has three different north direction lines of true north, magnetic north, and coordinate north, there are three different azimuths from a point to a target.

1.Calculate azimuth BA, BP according to the given coordinate data

xBA = xA-xB = + 123.461m

yBA = yA-yB = + 91.508m

Since xBA> 0, yBA> 0

It can be seen that BA is located in the first quadrant, that is,

BA = arctg = 36 ° 32'43.64 "

xBP = xP-xB = -37.819m

yBP = yP-yB = + 9.048m

Since xBP <0, yBP> 0

True bearing

All angles are set to 000 ° with true north and 360 ° after one clockwise turn.

therefore:

True North: 000 ° or 360 °

Orient: 090 °

True South: 180 °

True West: 270 °

Compass bearing

True north and south are the primary orientations, and true east and west are the secondary orientations.

In recent years, people have a comprehensive understanding of the advantages of carrying out wide azimuth observations, but for wide azimuth observations, there must be higher coverage times and smaller facets, that is, more expensive acquisition costs, which are somewhat prohibitive. To this end, this article

At present, researches on seismic attributes in the field of geology at home and abroad are all directed to conventional post-stack data. Although the post-stack seismic attribute extraction has been well developed, there are certain defects in using the post-stack data to calculate seismic attributes, because post-stack seismic attributes are mainly obtained through the difference in reflection amplitude between adjacent channels in space, which cannot be obtained. The finer anisotropic seismic attributes are obtained based on the difference in the reflection amplitude of seismic waves at different azimuth angles.

In the areas of fractures and faults, the reflection amplitudes of seismic waves at different azimuth angles are different, and the differences in reflection amplitudes between points in space and surrounding points may be caused by fractures or may be caused by lateral changes in lithology. In other words, the use of the difference in reflection amplitude between the points in the space and the surrounding points for fracture prediction has a stronger multiplicity, but the difference in the reflection amplitude of seismic waves with different azimuth angles is helpful to eliminate this multiplicity.

In the field of current geological exploration, the observation system is generally a beam-line observation system. The aspect ratio (ratio of the width of the horizontal arrangement and the length of the vertical arrangement) of this type of observation system is generally lower than 0.5. The observation method is narrow azimuth exploration. The advantage of narrow azimuth exploration is that there are fewer gun inspections, lower detection costs, and there will be no problems when exploring large reservoirs. However, when fracture-type oil and gas reservoirs with small storage capacity, the prediction accuracy of narrow azimuth exploration will be greatly reduced, and the location of oil and gas reservoirs cannot be accurately located, which also increases the production cost in disguise. It is with this demand that wide azimuth exploration has come into being.

Wide azimuth survey refers to an observation system with an aspect ratio greater than 0.5. In the early stage of the development of wide azimuth exploration, there were also obvious defects. Because it is necessary to satisfy the aspect ratio greater than 0.5, the number of artillery inspection pairs for narrower azimuth exploration will greatly increase, and the economic cost of exploration is greatly increased to a certain extent. However, with the rapid development of acquisition technology, wide azimuth exploration technology has also been greatly developed. With the application of Wandao seismograph and digital geophone, the cost of wide azimuth exploration has been greatly reduced. Objective demand has also promoted wide-azimuth exploration. ^[6]