/[escript]/branches/doubleplusgood/doc/inversion/DataSources.tex
ViewVC logotype

Diff of /branches/doubleplusgood/doc/inversion/DataSources.tex

Parent Directory Parent Directory | Revision Log Revision Log | View Patch Patch

revision 4344 by jfenwick, Wed Feb 27 03:42:40 2013 UTC revision 4345 by jfenwick, Fri Mar 29 07:09:41 2013 UTC
# Line 137  the domain will fail once \member{getDom Line 137  the domain will fail once \member{getDom
137  \end{methoddesc}  \end{methoddesc}
138    
139  \begin{methoddesc}[DomainBuilder]{setBackgroundMagneticFluxDensity}{B}  \begin{methoddesc}[DomainBuilder]{setBackgroundMagneticFluxDensity}{B}
140  sets the background magnetic flux density $B=(B_r,B_\theta,B_\phi)$ which is  sets the background magnetic flux density $B=(B_{North},B_{East},B_{Vertical})$
141  required for magnetic inversions.  which is required for magnetic inversions.
142  A implementation of the dipole approximation as described in  $B_{East}$ is ignored for 2-dimensional magnetic inversions.
 Equation~\ref{ref:MAG:EQU:5} is provided through the function  
 \member{simpleGeoMagneticFluxDensity} (see Section~\ref{sec:ref:DataSource}).  
 $B_\theta$ is ignored for 2-dimensional magnetic inversions.  
143  \end{methoddesc}  \end{methoddesc}
144    
145  \begin{methoddesc}[DomainBuilder]{getBackgroundMagneticFluxDensity}{}  \begin{methoddesc}[DomainBuilder]{getBackgroundMagneticFluxDensity}{}
# Line 196  The domain \member{origin}, number of el Line 193  The domain \member{origin}, number of el
193  \member{spacing} are provided as tuples or lists to aid with interpolation.  \member{spacing} are provided as tuples or lists to aid with interpolation.
194  \end{methoddesc}  \end{methoddesc}
195    
196    \begin{methoddesc}[DataSource]{getUtmZone}{}
197    Must be implemented to return the UTM zone that corresponds to the location of
198    this data set as returned by \member{getDataExtents}.
199    \end{methoddesc}
200    
201  \begin{methoddesc}[DataSource]{setSubsamplingFactor}{factor}  \begin{methoddesc}[DataSource]{setSubsamplingFactor}{factor}
202  Notifies the data source that data should be subsampled by \member{factor}.  Notifies the data source that data should be subsampled by \member{factor}.
203  This method does not need to be overwritten.  This method does not need to be overwritten.
# Line 219  don't support it. Line 221  don't support it.
221  \vspace{1em}\noindent The \module{esys.downunder.datasources} module contains the following helper  \vspace{1em}\noindent The \module{esys.downunder.datasources} module contains the following helper
222  functions:  functions:
223    
 \begin{funcdesc}{simpleGeoMagneticFluxDensity}{latitude%  
 \optional{, longitude=0.}}  
 returns an approximation of the geomagnetic flux density $B$ as described in  
 Equation~\ref{ref:MAG:EQU:5} for the given \member{latitude}.  
 The \member{longitude} parameter is currently ignored and the return value is  
 the tuple $(B_r, B_{\theta}, 0)$.  
 \end{funcdesc}  
   
224  \begin{funcdesc}{LatLonToUTM}{longitude, latitude%  \begin{funcdesc}{LatLonToUTM}{longitude, latitude%
225  \optional{, wkt_string=\None}}  \optional{, wkt_string=\None}}
226  converts one or more (longitude,latitude) pairs to the corresponding (x,y)  converts one or more (longitude,latitude) pairs to the corresponding (x,y)
227  coordinates in the \emph{Universal Transverse Mercator} (UTM) projection.  coordinates in the \emph{Universal Transverse Mercator} (UTM) projection.
228  This function requires the \module{pyproj} module for conversion and the  This function requires the \module{pyproj} module for conversion and the
229  \module{gdal} module to parse the \member{wkt_string} parameter if supplied.  \module{gdal} module to parse the \member{wkt_string} parameter if supplied.
230    The \member{wkt_string} parameter may describe the coordinate system used
231    for the input values as a \emph{Well-known Text} (WKT) string.
232  \end{funcdesc}  \end{funcdesc}
233    
234  \subsection{ER Mapper Raster Data}\label{sec:ref:DataSource:ERM}  \subsection{ER Mapper Raster Data}\label{sec:ref:DataSource:ERM}
# Line 247  Note, that the current implementation ma Line 243  Note, that the current implementation ma
243  datasets. For example, the only cell type understood is \emph{IEEE4ByteReal}  datasets. For example, the only cell type understood is \emph{IEEE4ByteReal}
244  at the moment.  at the moment.
245  To run inversions on a \emph{ER Mapper} dataset use the following constructor:  To run inversions on a \emph{ER Mapper} dataset use the following constructor:
246  \begin{classdesc}{ErMapperData}{datatype, headerfile%  \begin{classdesc}{ErMapperData}{data_type, headerfile%
247  \optional{, datafile=\None}%  \optional{, datafile=\None}%
248  \optional{, altitude=0.}}  \optional{, altitude=0.}%
249    \optional{, error=\None}%
250    \optional{, scale_factor=\None}%
251    \optional{, null_value=\None}}
252  Creates a new data source from \emph{ER Mapper} data.  Creates a new data source from \emph{ER Mapper} data.
253  The parameter \member{datatype} must be one of  The parameter \member{data_type} must be one of
254  \class{DataSource}.\member{GRAVITY} or \class{DataSource}.\member{MAGNETIC}  \class{DataSource}.\member{GRAVITY} or \class{DataSource}.\member{MAGNETIC}
255  depending on the type of data, \member{headerfile} is the name of the header  depending on the type of data, \member{headerfile} is the name of the header
256  file, \member{datafile} specifies the name of the data file and  file while \member{datafile} specifies the name of the data file.
 \member{altitude} specifies the altitude in meters of the measurements.  
257  The parameter \member{datafile} can be left blank if the name is identical to  The parameter \member{datafile} can be left blank if the name is identical to
258  the header file except for the file extension. The \member{altitude} parameter  the header file except for the file extension.
259  is only used with 3-dimensional domains and determines the vertical location  The \member{altitude} parameter can be used to shift a 2-dimensional slice of
260  of the 2-dimensional slice of data within the domain.  data vertically within a 3-dimensional domain.
261    Use \member{error} to set the (constant) measurement error with the same units
262    used by the measurements. By default a value of $2$ units is assumed which
263    equals $0.2 \; mgal$ or $2 \; nT$ depending on the data type.
264    Since ER Mapper files do not store any information about data units or scale
265    the \member{scale_factor} may be used to provide this information.
266    If not set, gravity data is assumed to be given in $\frac{\mu m}{sec^2}$ while
267    magnetic data is assumed to be given in $nT$.
268    Finally, the \member{null_value} parameter can be used to override the value
269    for the areas to be ignored (see Section~\ref{SEC:P1:GRAV:REMARK:DATAHOLES})
270    which is usually provided in the ER Mapper header file.
271  \end{classdesc}  \end{classdesc}
272    
273  \subsection{NetCDF Data}\label{sec:ref:DataSource:NETCDF}  \subsection{NetCDF Data}\label{sec:ref:DataSource:NETCDF}
# Line 278  To plot such an input file including coo Line 286  To plot such an input file including coo
286  The interface to \class{NetCdfData} looks as follows:  The interface to \class{NetCdfData} looks as follows:
287    
288  \begin{classdesc}{NetCdfData}{datatype, filename%  \begin{classdesc}{NetCdfData}{datatype, filename%
289  \optional{, altitude=0.}}  \optional{, altitude=0.}%
290    \optional{, data_variable=\None}%
291    \optional{, error=\None}%
292    \optional{, scale_factor=\None}%
293    \optional{, null_value=\None}}
294  Creates a new data source from compatible \netcdf data.  Creates a new data source from compatible \netcdf data.
295  The parameter \member{datatype} must be one of  The two required parameters are \member{datatype}, which must be one of
296  \class{DataSource}.\member{GRAVITY} or \class{DataSource}.\member{MAGNETIC}  \class{DataSource}.\member{GRAVITY} or \class{DataSource}.\member{MAGNETIC}
297  depending on the type of data, \member{filename} is the name of the file and  depending on the type of data, and \member{filename} which is the name of the
298  \member{altitude} specifies the altitude in meters of the measurements.  file containing the data.
299  The \member{altitude} parameter is only used with 3-dimensional domains and  The \member{altitude} parameter can be used to shift a 2-dimensional slice of
300  determines the vertical location of the 2-dimensional slice of data within the  data vertically within a 3-dimensional domain.
301  domain.  Set the \member{data_variable} parameter to the name of the \netcdf variable
302    that contains the measurements unless there is only one data variable in the
303    file in which case the parameter can be left empty.
304    Use \member{error} to set the (constant) measurement error with the same units
305    used by the measurements or the name of the \netcdf variable that contains this
306    information. By default a value of $2$ units is assumed which equals
307    $0.2 \; mgal$ or $2 \; nT$ depending on the data type.
308    The current implementation does not use the units attribute (if available)
309    within the \netcdf file. Use the \member{scale_factor} argument to provide this
310    information instead.
311    If not set, gravity data is assumed to be given in $\frac{\mu m}{sec^2}$ while
312    magnetic data is assumed to be given in $nT$.
313    Finally, the \member{null_value} parameter can be used to override the value
314    for the areas to be ignored (see Section~\ref{SEC:P1:GRAV:REMARK:DATAHOLES})
315    which is usually provided in the \netcdf file.
316  \end{classdesc}  \end{classdesc}
317    
318  \subsection{Synthetic Data}  \subsection{Synthetic Data}

Legend:
Removed from v.4344  
changed lines
  Added in v.4345

  ViewVC Help
Powered by ViewVC 1.1.26