User guide¶
Units (gmeterpy.units)¶
The unit aware calculations is one of the main goals of the gMeterPy. We are using astropy.units sub-package for this. To use units you need to import gmeterpy.units module:
>>> import gmeterpy.units as u
And now you can work with gravity acceleration SI units:
>>> gravity = 9.8 * u.m / u.s**2
>>> gravity
<Quantity 9.8 m / s2>
and convert them to more convinient CGS units:
>>> gravity.to(u.Gal)
<Quantity 980. Gal>
and even use prefixes (u – micro):
>>> gravity.to(u.uGal)
<Quantity 9.8e+08 uGal>
In addition to Astropy built-in units we introduce Eotvos unit for the gravity gradient:
>>> gradient = 0.3086 * u.mGal / u.m
>>> gradient.to(u.E)
<Quantity 3086. E>
Constants (gmeterpy.constants)¶
The gMeterPy uses astropy.constants sub-package for handling constants. We expand it for some frequently used constants in gravimetry.
Constant |
Description |
|
---|---|---|
omega |
Mean angular rotation rate of the Earth |
|
atm_sens |
Default gravity/pressure sensitivity (0.3 uGal / mbar) |
International Standard Atmosphere¶
The Standard Atmosphere (ISO 2533:1975) is used to calculate the normal pressure in the atmospheric pressure correction.
Constant |
Description |
|
---|---|---|
p0 |
Standard atmospheric pressure at sea level |
|
L |
Temperature lapse rate |
|
Tn |
Standard thermodynamic air temperature at sea level |
|
gn |
Standard acceleration of free-fall |
|
M |
Air molar mass at sea level |
|
R |
Universal gas constant |