Note: This addon document is for an older version of GRASS GIS that will be discontinued soon. You should upgrade your GRASS GIS installation, and read the current addon manual page.
NAME
r.crater - Creates meteorites from craters (-c) or craters from meteorites (default).KEYWORDS
raster, planetary, impact, meteorite, craterSYNOPSIS
Flags:
- -c
- Estimate crater diameter from projectile size [m]
- -t
- output the time of crater formation for Pi scaling [s]
- -g
- use the Gault instead of default Pi scaling
- -y
- use the Yield instead of default Pi scaling
- --overwrite
- Allow output files to overwrite existing files
- --help
- Print usage summary
- --verbose
- Verbose module output
- --quiet
- Quiet module output
- --ui
- Force launching GUI dialog
Parameters:
- impactor_velocity=name [required]
- Name of impactor velocity raster map [km/s]
- impactor_angle=name [required]
- Name of impactor angle raster map [dd.ddd]
- target_density=name [required]
- Name of target density raster map [kg/m^3]
- gravity_acceleration=name [required]
- Name of gravity acceleration raster map [m/s^-2]
- target_type=name [required]
- Name of target type raster map [1=liq.H2O, 2=Loose Sand, 3=Competent Rock/Saturated Soil]
- impactor_density=name [required]
- Name of impactor density raster map [kg/m^3]
- projectile_diameter=name
- Flag -c: Name of projectile diameter raster map [m]
- transient_crater_diameter=name
- Default mode: Name of transient crater diameter raster map [m]
- final_crater_diameter=name
- Default mode: Name of final crater diameter raster map [m]
- output=name [required]
- Name for projectile size (default) or crater size (-c) or crater creation time (-t) raster map [m] or [s]
Table of contents
DESCRIPTION
r.crater This program estimates the size of a gravity dominated impact crater or the projectile that made it.
Forward mode This mode needs to know the projectile details
L: projectile diameter (m)
r_proj: projectile density (kg/m^3)
Vi: Projectile velocity (km/s)
theta: projectile impact angle (degrees) for Gault scaling law (flag2)
Solid_rock or not (1 or 0) for Gault scaling law (flag2)
Backward modeThis mode needs to know the crater details
NOTES
Gault scaling law saturates at craters 1000 Diameter Apparent Transient, and was essentially designed for regolith (Moon surface).Below is explanation from the Meloch Fortran code (not included because of copyright)
Three different estimates are presented, but the pi-scaling method is currently considered the best!
Impact conditions: argv[1]: enter the impact velocity in km/sec argv[2]: enter the impact angle in degrees
Target descriptors: argv[3]: enter the target density in kg/m^3 argv[4]: enter the acceleration of gravity in m/sec^2
argv[5]: enter the target type, (1-3): type 1 = liquid water type 2 = loose sand type 3 = competent rock or saturated soil argv[6]: enter the projectile density in kg/m^3
argv[7]: enter the type of computation desired (1 or 2): Mode 1, crater size Mode 2, projectile size
Mode 1: Estimate crater diameter from projectile size Mode 1 case: Projectile descriptors: argv[8]: enter the projectile diameter in m
Mode 2: Estimate crater size from crater diameter*/ Mode 2 case: Crater descriptor: argv[8]: enter the transient crater diameter in m (if the final, not the transient crater diameter is known, enter zero (0.0) here) argv[9]: [optional] enter the final crater diameter in m
NOTES
SEE ALSO
r.drain, r.out.asciiAUTHOR
Yann CheminSOURCE CODE
Available at: r.crater source code (history)
Latest change: Mon Jun 28 07:54:09 2021 in commit: 1cfc0af029a35a5d6c7dae5ca7204d0eb85dbc55
Note: This addon document is for an older version of GRASS GIS that will be discontinued soon. You should upgrade your GRASS GIS installation, and read the current addon manual page.
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© 2003-2023 GRASS Development Team, GRASS GIS 7.8.8dev Reference Manual