java.lang.Object
- org.orekit.models.earth.ViennaModelCoefficientsLoader

All Implemented Interfaces:: DataLoader

public class ViennaModelCoefficientsLoader
extends Object
implements DataLoader

Loads Vienna tropospheric coefficients a given input stream. A stream contains, for a given day and a given hour, the hydrostatic and wet zenith delays and the ah and aw coefficients used for the computation of the mapping function. The coefficients are given with a time interval of 6 hours.

A bilinear interpolation is performed the case of the user initialize the latitude and the longitude with values that are not contained in the stream.

The coefficients are obtained from Vienna Mapping Functions Open Access Data. Find more on the files at the VMF Model Documentation.

The files have to be extracted to UTF-8 text files before being read by this loader.

After extraction, it is assumed they are named VMFG_YYYYMMDD.Hhh for ViennaOneModel and VMF3_YYYYMMDD.Hhh ViennaThreeModel. Where YYYY is the 4-digits year, MM the month, DD the day and hh the 2-digits hour.

The format is always the same, with and example shown below for VMF1 model.

Example:

 ! Version:            1.0
 ! Source:             J. Boehm, TU Vienna (created: 2018-11-20)
 ! Data_types:         VMF1 (lat lon ah aw zhd zwd)
 ! Epoch:              2018 11 19 18 00  0.0
 ! Scale_factor:       1.e+00
 ! Range/resolution:   -90 90 0 360 2 2.5
 ! Comment:            http://vmf.geo.tuwien.ac.at/trop_products/GRID/2.5x2/VMF1/VMF1_OP/
  90.0   0.0 0.00116059  0.00055318  2.3043  0.0096
  90.0   2.5 0.00116059  0.00055318  2.3043  0.0096
  90.0   5.0 0.00116059  0.00055318  2.3043  0.0096
  90.0   7.5 0.00116059  0.00055318  2.3043  0.0096
  90.0  10.0 0.00116059  0.00055318  2.3043  0.0096
  90.0  12.5 0.00116059  0.00055318  2.3043  0.0096
  90.0  15.0 0.00116059  0.00055318  2.3043  0.0096
  90.0  17.5 0.00116059  0.00055318  2.3043  0.0096
  90.0  20.0 0.00116059  0.00055318  2.3043  0.0096
  90.0  22.5 0.00116059  0.00055318  2.3043  0.0096
  90.0  25.0 0.00116059  0.00055318  2.3043  0.0096
  90.0  27.5 0.00116059  0.00055318  2.3043  0.0096

Author:: Bryan Cazabonne

Field Summary

Fields
Modifier and Type Field Description

static String DEFAULT_SUPPORTED_NAMES
Default supported files name pattern.

Constructor Summary

Constructors
Constructor	Description
`ViennaModelCoefficientsLoader(double latitude, double longitude, ViennaModelType type)`	Constructor with default supported names.
`ViennaModelCoefficientsLoader(String supportedNames, double latitude, double longitude, ViennaModelType type)`	Constructor with supported names given by user.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`double[]`	`getA()`	Returns the a coefficients array.
`String`	`getSupportedNames()`	Returns the supported names of the loader.
`double[]`	`getZenithDelay()`	Returns the zenith delay array.
`void`	`loadData(InputStream input, String name)`	Load data from a stream.
`void`	`loadViennaCoefficients()`	Load the data using supported names .
`void`	`loadViennaCoefficients(DateTimeComponents dateTimeComponents)`	Load the data for a given day.
`boolean`	`stillAcceptsData()`	Check if the loader still accepts new data.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - DEFAULT_SUPPORTED_NAMES
```
public static final String DEFAULT_SUPPORTED_NAMES
```
    Default supported files name pattern.
    
    See Also:
    
    Constant Field Values
- Constructor Detail
  - ViennaModelCoefficientsLoader
```
public ViennaModelCoefficientsLoader(String supportedNames,
                                     double latitude,
                                     double longitude,
                                     ViennaModelType type)
```
    Constructor with supported names given by user.
    
    Parameters:
    
    supportedNames - Supported names
    
    latitude - geodetic latitude of the station, in radians
    
    longitude - geodetic latitude of the station, in radians
    
    type - the type of Vienna tropospheric model (one or three)
  - ViennaModelCoefficientsLoader
```
public ViennaModelCoefficientsLoader(double latitude,
                                     double longitude,
                                     ViennaModelType type)
```
    Constructor with default supported names.
    
    Parameters:
    
    latitude - geodetic latitude of the station, in radians
    
    longitude - geodetic latitude of the station, in radians
    
    type - the type of Vienna tropospheric model (one or three)
- Method Detail
  - getA
```
public double[] getA()
```
    Returns the a coefficients array.
    
    double[0] = a_h
    double[1] = a_w
    Returns:
    
    the a coefficients array
  - getZenithDelay
```
public double[] getZenithDelay()
```
    Returns the zenith delay array.
    
    double[0] = D_hz → zenith hydrostatic delay
    double[1] = D_wz → zenith wet delay
    Returns:
    
    the zenith delay array
  - getSupportedNames
```
public String getSupportedNames()
```
    Returns the supported names of the loader.
    
    Returns:
    
    the supported names
  - loadViennaCoefficients
```
public void loadViennaCoefficients()
```
    Load the data using supported names .
  - loadViennaCoefficients
```
public void loadViennaCoefficients(DateTimeComponents dateTimeComponents)
```
    Load the data for a given day.
    
    Parameters:
    
    dateTimeComponents - date and time component.
    
    Throws:
    
    OrekitException - if the coefficients could not be loaded
  - stillAcceptsData
```
public boolean stillAcceptsData()
```
    Description copied from interface: DataLoader
    
    Check if the loader still accepts new data.
    This method is used to speed up data loading by interrupting crawling the data sets as soon as a loader has found the data it was waiting for. For loaders that can merge data from any number of sources (for example JPL ephemerides or Earth Orientation Parameters that are split among several files), this method should always return true to make sure no data is left over.
    
    Specified by:
    
    stillAcceptsData in interface DataLoader
    
    Returns:
    
    true while the loader still accepts new data
  - loadData
```
public void loadData(InputStream input,
                     String name)
              throws IOException,
                     ParseException
```
    Description copied from interface: DataLoader
    
    Load data from a stream.
    
    Specified by:
    
    loadData in interface DataLoader
    
    Parameters:
    
    input - data input stream
    
    name - name of the file (or zip entry)
    
    Throws:
    
    IOException - if data can't be read
    
    ParseException - if data can't be parsed or if some loader specific error occurs

Class ViennaModelCoefficientsLoader

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

DEFAULT_SUPPORTED_NAMES

Constructor Detail

ViennaModelCoefficientsLoader

ViennaModelCoefficientsLoader

Method Detail

getA

getZenithDelay

getSupportedNames

loadViennaCoefficients

loadViennaCoefficients

stillAcceptsData

loadData