/* Copyright 2002-2017 CS Systèmes d'Information
* Licensed to CS Systèmes d'Information (CS) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* CS licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.orekit.forces.gravity.potential;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.nio.charset.StandardCharsets;
import java.util.HashMap;
import java.util.Map;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import org.hipparchus.exception.DummyLocalizable;
import org.hipparchus.util.FastMath;
import org.orekit.errors.OrekitException;
import org.orekit.errors.OrekitMessages;
/** Supported Ocean load Deformation coefficients (Love numbers k'<sub>i</sub>).
* @see GravityFieldFactory
* @since 6.1
* @author Luc Maisonobe
*/
public enum OceanLoadDeformationCoefficients {
/** Coefficients from IERS 1996 conventions.
* <p>
* Note that coefficients from conventions IERS 1996, 2003 and 2010 are all equal to each other.
* </p>
*/
IERS_1996 {
/** {@inheritDoc} */
@Override
public double[] getCoefficients() {
return new double[] {
// IERS conventions 1996, chapter 6 page 48
0.0, 0.0, -0.3075, -0.195, -0.132, -0.1032, -0.0892
};
}
},
/** Coefficients from IERS 2003 conventions.
* <p>
* Note that coefficients from conventions IERS 1996, 2003 and 2010 are all equal to each other.
* </p>
*/
IERS_2003 {
/** {@inheritDoc} */
@Override
public double[] getCoefficients() {
return new double[] {
// IERS conventions 2003, section 6.4 page 67 equation 13
0.0, 0.0, -0.3075, -0.195, -0.132, -0.1032, -0.0892
};
}
},
/** Coefficients from IERS 2010 conventions.
* <p>
* Note that coefficients from conventions IERS 1996, 2003 and 2010 are all equal to each other.
* </p>
*/
IERS_2010 {
/** {@inheritDoc} */
@Override
public double[] getCoefficients() {
return new double[] {
// IERS conventions 2010, section 6.3.1 page 91
0.0, 0.0, -0.3075, -0.195, -0.132, -0.1032, -0.0892
};
}
},
/** Coefficients computed by Pascal Gégout, CNRS / UMR5563 (GET).
* <p>
* These coefficients are available up to degree 250.
* </p>
*/
GEGOUT {
/** Coefficients resources. */
private static final String RESOURCE_NAME = "/assets/org/orekit/fic.love.kp.gegout";
/** Pattern for fields with integer type. */
private static final String INTEGER_TYPE_PATTERN = "[-+]?\\p{Digit}+";
/** Pattern for fields with real type. */
private static final String REAL_TYPE_PATTERN = "[-+]?(?:(?:\\p{Digit}+(?:\\.\\p{Digit}*)?)|(?:\\.\\p{Digit}+))(?:[eE][-+]?\\p{Digit}+)?";
/** {@inheritDoc} */
@Override
public double[] getCoefficients() throws OrekitException {
final InputStream stream =
OceanLoadDeformationCoefficients.class.getResourceAsStream(RESOURCE_NAME);
if (stream == null) {
throw new OrekitException(OrekitMessages.UNABLE_TO_FIND_FILE, RESOURCE_NAME);
}
// regular lines are simply a degree index followed by the coefficient for this degree
final StringBuilder builder = new StringBuilder("^\\p{Space}*");
builder.append("(").append(INTEGER_TYPE_PATTERN).append(")");
builder.append("\\p{Space}+");
builder.append("(").append(REAL_TYPE_PATTERN).append(")");
builder.append("\\p{Space}*$");
final Pattern regularLinePattern = Pattern.compile(builder.toString());
int lineNumber = 0;
String line = null;
try (BufferedReader reader = new BufferedReader(new InputStreamReader(stream, StandardCharsets.UTF_8))) {
// setup the reader
lineNumber = 0;
int maxDegree = 0;
final Map<Integer, Double> map = new HashMap<Integer, Double>();
for (line = reader.readLine(); line != null; line = reader.readLine()) {
lineNumber++;
final Matcher regularMatcher = regularLinePattern.matcher(line);
if (regularMatcher.matches()) {
// we have found a regular data line
final int degree = Integer.parseInt(regularMatcher.group(1));
final double coefficient = Double.parseDouble(regularMatcher.group(2));
map.put(degree, coefficient);
maxDegree = FastMath.max(maxDegree, degree);
}
}
final double[] coefficients = new double[maxDegree + 1];
for (final Map.Entry<Integer, Double> entry : map.entrySet()) {
coefficients[entry.getKey()] = entry.getValue();
}
return coefficients;
} catch (NumberFormatException nfe) {
throw new OrekitException(OrekitMessages.UNABLE_TO_PARSE_LINE_IN_FILE,
lineNumber, RESOURCE_NAME, line);
} catch (IOException ioe) {
throw new OrekitException(ioe, new DummyLocalizable(ioe.getMessage()));
}
}
};
/** Get the load deformation coefficients for ocean tides.
* @return load deformation coefficients for ocean tides
* @exception OrekitException if coefficients cannot be loaded
*/
public abstract double[] getCoefficients() throws OrekitException;
}