Changes

|+ {{table number|1}}Energy sources

|+ {{table number|1}}Energy sources

|-

|-

! Source

! Source || Application || Advantages || Disadvantages

! Application

! Advantages

! Disadvantages

|-

|-

| Explosives

| Explosives || General acquisition || Short, broad band pulse. Source can be placed below weathering layer. || Requires expensive shothole drilling. Frequency dependent on material in which explosion occurs. Dangerous to handle.

| General acquisition

| Short, broad band pulse. Source can be placed below weathering layer.

| Requires expensive shothole drilling. Frequency dependent on material in which explosion occurs. Dangerous to handle.

|-

|-

| Vibrators

| Vibrators || General acquisition || Minimal cultural and environmental impact. Controlled frequency source. Narrow frequency band can increase signal to noise ratio. No shot holes required. || Shallow weathering can cause statics problems. Base-plate to ground coupling can be a problem. More complex recording and processing.

| General acquisition

| Minimal cultural and environmental impact. Controlled frequency source. Narrow frequency band can increase signal to noise ratio. No shot holes required.

| Shallow weathering can cause statics problems. Base-plate to ground coupling can be a problem. More complex recording and processing.

|-

|-

| Gas or air guns

| Gas or air guns || Acquisition in rough terrain || Cheap. Heli-portable. Can use multiple sources. No shot holes required. || Limited energy penetration. Ground roll problems. Requires longer offsets. Shallow weathering can cause statics problems.

| Acquisition in rough terrain

| Cheap. Heli-portable. Can use multiple sources. No shot holes required.

| Limited energy penetration. Ground roll problems. Requires longer offsets. Shallow weathering can cause statics problems.

|-

|-

| Weight drop

| Weight drop || General acquisition. Desert acquisition. || Cheap. No shot holes required. || Cannot synchronize sources. Ground roll problems. Requires longer offsets. Shallow weathering can cause statics problems.

| General acquisition. Desert acquisition.

| Cheap. No shot holes required.

| Cannot synchronize sources. Ground roll problems. Requires longer offsets. Shallow weathering can cause statics problems.

|}

|}

==Receiver==

==Receiver==

[[file:seismic-data-acquisition-on-land_fig6.png|thumb|{{figure number|6}}Geophone. (Photo. Copyright: Western Atlas International.]]

[[file:seismic-data-acquisition-on-land_fig6.png|300px|thumb|{{figure number|6}}Geophone. (Photo. Copyright: Western Atlas International.]]

A ''geophone'' is a mechanical device that transforms seismic energy into electrical voltage ([[:file:seismic-data-acquisition-on-land_fig6.png|Figure 6]]). Individual geophones are often wired together and configured in arrays along a cable. These arrays are designed much the same as source arrays and for the same basic reasons, that is, to maximize detection of reflected energy and to reduce the amount of noise. However, it is important that for any geophone array to work, the individual phones must be properly planted and not just thrown out on the ground, stuck into trees, hung in bushes, or set on rocks.

A ''geophone'' is a mechanical device that transforms seismic energy into electrical voltage ([[:file:seismic-data-acquisition-on-land_fig6.png|Figure 6]]). Individual geophones are often wired together and configured in arrays along a cable. These arrays are designed much the same as source arrays and for the same basic reasons, that is, to maximize detection of reflected energy and to reduce the amount of noise. However, it is important that for any geophone array to work, the individual phones must be properly planted and not just thrown out on the ground, stuck into trees, hung in bushes, or set on rocks.

[[Category:Geophysical methods]]

[[Category:Geophysical methods]]

[[Category:Seismic data acquisition]]

[[Category:Seismic data acquisition]]