ray2mesh.8

用于2维的射线追踪

.TH ray2mesh 8 2004-01-01

.SH NAME
ray2mesh \- traces seismic rays in geographic meshes 

.SH SYNOPSIS

.B ray2mesh 
.RB [\-h|\-\-help]
.PP
.B ray2mesh 
.RB [\-v|\-\-version]
.PP 
.B ray2mesh
[\-s|\-\-source\ x,y,z] [\-d|\-\-dest\ x,y,z] [\-p|\-\-phase phase\_name] [\-l|\-\-length FLOAT] [\-t|\-\-tables DIR]
.PP
.B ray2mesh
.RB 
[\-m|\-\-meshfile FILE] 
[\-i|\-\-input FILE]
[\-o|\-\-output FILE] 
[\-l|\-\-length FLOAT]
[\-f|\-\-format=r2m,sco] 
[\-\-iterate] 
[\-\-vmodel FILE] 
[\-\-filtered FILE] 
[\-\-set-filter=res,dist,nbray] 
[\-t|\-\-tables DIR]
[\-L|\-\-mem-limit INT]
[\-c|\-\-chunksize INT]

.SH DESCRIPTION
.P
Ray2mesh is part of the gimbos suite software.
It is used to analyze how the mesh of a geographic area is impacted by
the ray-tracing of seismic rays. 
.P
Ray2mesh comes in various flavors, depending on the choice made during compilation.
Invoking it with \-\-version will list the important flavor flags.
It may first be a 
.B sequential 
or
.B parallel  
binary (it uses MPI). A paralell binary implements either a
.B scatter
or 
.B master/slave
parallelization paradigm. Use scatter or master/slave on a parallel machine, 
and only master/slave in an heteregoneous environment.

.SH OPTIONS
.TP
.BI [\-s|\-\-source\ x,y,z] [\-d|\-\-dest\ x,y,z]
Source and destination of a seismic ray. Used to trace an individual ray.
Option 
.B [\-p |\-\-phase]
is required to trace an individual ray.
.TP
.BI "[\-p|\-\-phase phase\_name]"
Phase name conformant to seismic notation used in libraycode(8). 
.TP
.BI "[\-m|\-\-meshfile FILE]" 
The name of a mesh description conformant to libmesh(8) format. 
.TP
.BI "[\-i|\-\-input FILE]" 
The name of the ray data set. 
Each file line represents one seismic ray (or bundle) with the event ID (resp. 
number of ray in the bundle), source, destination, phase and observed ray 
travel-time values in that order. 
Source and destination are each encoded as three real numbers in geographic coordinates: latitude, longitude, depth in that order from left to right, with angles in degrees, depth in km. A sample line is :
.nf
   3 58.5840 -137.7780 0.0 60.825000 -137.503889 -1.41 Pn 51.28
.fi

.TP
.BI "[\-o|\-\-output FILE]"
Give the basename of the output file where the results go.

.TP
.BI "[\-\-filtered FILE]"
Creates a new file containing ray data that were traced without errors.
The created file is thus a subset of the input data file. 
Use this to clean your input data set. Added as the last column, the 
residual time.
.TP
.BI "[\-l|\-\-length FLOAT]"
Specify the distance between two sample points in the ray-tracing process.
Default is 2 kms. A longer distance implies a little less computation time 
and memory used for ray sampling. 
A shorter distance yields greater precision.
.TP
.BI "[\-\-iterate]"
Iterate on ray computation to increase precison of the last node position,
which should match the receiver location (may be very time consuming).
.TP
.BI "[\-\-vmodel]"
Specify a particular earth velocity model rather than the iasp91 default one.
.TP
.BI "[\-f|\-\-format]"
Generates output results in sco or r2m fomated file.
.TP
.BI "[\-t|\-\-tables DIR]"
Specify an alternate path to find IASP tables. 
When the velocity model is IASP, the ray-tracer needs the tables iasp91.hed and iasp91.tbl. Use this if you have moved these tables somewhere else than where installed by the installation process of iasp.
.TP
.BI "[\-L|\-\-limit INT]"
Limit memory storage used to a given amount (in MBytes).
Each time the specified memory size is reached, a new file is created, 
the results computed moved to the file, and the memory freed. 
Use this to compute big data sets on computer(s) with limited RAM.  
This option desactivates the all-to-all communication between processors.
In the end, you have to merge the partial result files (merger program).
.TP
.BI "[\-\-set-filter FLOAT,FLOAT,INT]"
Set a filter on ray set. Three parameters are required in that order :
maximum residual time in second, maximum distance in degre between source
and receiver, and minimum number of rays in a bundle.
A ray is filtered out if at leat one of his parameter do not fit with the
filter parameters.
.TP
.BI " [\-c|\-\-chunksize INT]"
ray number per chunks ditributed to slaves in master/slave mode.




.SH SEE ALSO
merger(8), libraycode(8), libraydescartes(8), libmesh(8), gimbos(8)