1 /* Copyright 2002-2020 CS GROUP
2 * Licensed to CS GROUP (CS) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * CS licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.orekit.forces.gravity.potential;
18
19 import java.io.BufferedReader;
20 import java.io.IOException;
21 import java.io.InputStream;
22 import java.io.InputStreamReader;
23 import java.nio.charset.StandardCharsets;
24 import java.util.Map;
25 import java.util.regex.Matcher;
26 import java.util.regex.Pattern;
27
28 import org.hipparchus.util.FastMath;
29 import org.orekit.errors.OrekitException;
30 import org.orekit.errors.OrekitMessages;
31
32 /** Reader for ocean tides files following the fes2004.dat format.
33 * @since 6.1
34 * @author Luc Maisonobe
35 */
36 public class FESCHatEpsilonReader extends OceanTidesReader {
37
38 /** Default pattern for fields with unknown type (non-space characters). */
39 private static final String UNKNOWN_TYPE_PATTERN = "\\S+";
40
41 /** Pattern for fields with integer type. */
42 private static final String INTEGER_TYPE_PATTERN = "[-+]?\\p{Digit}+";
43
44 /** Pattern for fields with real type. */
45 private static final String REAL_TYPE_PATTERN = "[-+]?(?:(?:\\p{Digit}+(?:\\.\\p{Digit}*)?)|(?:\\.\\p{Digit}+))(?:[eE][-+]?\\p{Digit}+)?";
46
47 /** Pattern for fields with Doodson number. */
48 private static final String DOODSON_TYPE_PATTERN = "\\p{Digit}{2,3}[.,]\\p{Digit}{3}";
49
50 /** Pattern for regular data. */
51 private static final Pattern PATTERN = Pattern.compile("[.,]");
52
53 /** Sea water fensity. */
54 private static final double RHO = 1025;
55
56 /** Gravitational constant (from IERS 2010, chapter 1). */
57 private static final double BIG_G = 6.67428e-11;
58
59 /** Earth mean gravity AT EQUATOR (from IERS 2010, chapter 1). */
60 private static final double GE = 9.7803278;
61
62 /** Scale of the CHat parameters. */
63 private final double scaleCHat;
64
65 /** Scale of the epsilon parameters. */
66 private final double scaleEpsilon;
67
68 /** Load deformation coefficients for ocean tides. */
69 private final OceanLoadDeformationCoefficients oldc;
70
71 /** Map for astronomical amplitudes. */
72 private final Map<Integer, Double> astronomicalAmplitudes;
73
74 /** Simple constructor.
75 * @param supportedNames regular expression for supported files names
76 * @param scaleCHat scale of the CHat parameters
77 * @param scaleEpsilon scale of the epsilon parameters
78 * @param oldc load deformation coefficients for ocean tides
79 * @param astronomicalAmplitudes map for astronomical amplitudes
80 * @see AstronomicalAmplitudeReader#getAstronomicalAmplitudesMap()
81 */
82 public FESCHatEpsilonReader(final String supportedNames,
83 final double scaleCHat, final double scaleEpsilon,
84 final OceanLoadDeformationCoefficients oldc,
85 final Map<Integer, Double> astronomicalAmplitudes) {
86 super(supportedNames);
87 this.scaleCHat = scaleCHat;
88 this.scaleEpsilon = scaleEpsilon;
89 this.oldc = oldc;
90 this.astronomicalAmplitudes = astronomicalAmplitudes;
91 }
92
93 /** {@inheritDoc} */
94 @Override
95 public void loadData(final InputStream input, final String name)
96 throws IOException {
97
98 // FES ocean tides models have the following form:
99 // Ocean tide model: FES2004 normalized model (fev. 2004) up to (100,100) in cm
100 // (long period from FES2002 up to (50,50) + equilibrium Om1/Om2, atmospheric tide NOT included)
101 // Doodson Darw n m Csin+ Ccos+ Csin- Ccos- C+ eps+ C- eps-
102 // 55.565 Om1 2 0 -0.540594 0.000000 0.000000 0.000000 0.5406 270.000 0.0000 0.000
103 // 55.575 Om2 2 0 -0.005218 0.000000 0.000000 0.000000 0.0052 270.000 0.0000 0.000
104 // 56.554 Sa 1 0 0.017233 0.000013 0.000000 0.000000 0.0172 89.957 0.0000 0.000
105 // 56.554 Sa 2 0 -0.046604 -0.000903 0.000000 0.000000 0.0466 268.890 0.0000 0.000
106 // 56.554 Sa 3 0 -0.000889 0.000049 0.000000 0.000000 0.0009 273.155 0.0000 0.000
107 final String[] fieldsPatterns = new String[] {
108 DOODSON_TYPE_PATTERN,
109 UNKNOWN_TYPE_PATTERN,
110 INTEGER_TYPE_PATTERN,
111 INTEGER_TYPE_PATTERN,
112 REAL_TYPE_PATTERN,
113 REAL_TYPE_PATTERN,
114 REAL_TYPE_PATTERN,
115 REAL_TYPE_PATTERN,
116 REAL_TYPE_PATTERN,
117 REAL_TYPE_PATTERN,
118 REAL_TYPE_PATTERN,
119 REAL_TYPE_PATTERN
120 };
121 final StringBuilder builder = new StringBuilder("^\\p{Space}*");
122 for (int i = 0; i < fieldsPatterns.length; ++i) {
123 builder.append("(");
124 builder.append(fieldsPatterns[i]);
125 builder.append(")");
126 builder.append((i < fieldsPatterns.length - 1) ? "\\p{Space}+" : "\\p{Space}*$");
127 }
128 final Pattern regularLinePattern = Pattern.compile(builder.toString());
129
130 final double commonFactor = 4 * FastMath.PI * BIG_G * RHO / GE;
131 final double[] kPrime = oldc.getCoefficients();
132
133 // parse the file
134 startParse(name);
135 try (BufferedReader r = new BufferedReader(new InputStreamReader(input, StandardCharsets.UTF_8))) {
136 int lineNumber = 0;
137 for (String line = r.readLine(); line != null; line = r.readLine()) {
138 ++lineNumber;
139 final Matcher regularMatcher = regularLinePattern.matcher(line);
140 if (regularMatcher.matches()) {
141 // we have found a regular data line
142
143 // parse fields
144 final int doodson = Integer.parseInt(PATTERN.matcher(regularMatcher.group(1)).replaceAll(""));
145 final int n = Integer.parseInt(regularMatcher.group(3));
146 final int m = Integer.parseInt(regularMatcher.group(4));
147
148 if (canAdd(n, m)) {
149
150 final double cHatPlus = scaleCHat * Double.parseDouble(regularMatcher.group(9));
151 final double ePlus = scaleEpsilon * Double.parseDouble(regularMatcher.group(10));
152 final double cHatMinus = scaleCHat * Double.parseDouble(regularMatcher.group(11));
153 final double eMinus = scaleEpsilon * Double.parseDouble(regularMatcher.group(12));
154
155 // compute bias from table 6.6
156 final double hf = astronomicalAmplitudes.getOrDefault(doodson, 0.0);
157 final int cGamma = doodson / 100000;
158 final double chiF;
159 if (cGamma == 0) {
160 chiF = hf > 0 ? FastMath.PI : 0.0;
161 } else if (cGamma == 1) {
162 chiF = hf > 0 ? 0.5 * FastMath.PI : -0.5 * FastMath.PI;
163 } else if (cGamma == 2) {
164 chiF = hf > 0 ? 0.0 : FastMath.PI;
165 } else {
166 chiF = 0;
167 }
168
169 // compute reference gravity coefficients by converting height coefficients
170 // IERS conventions 2010, equation 6.21
171 if (n >= kPrime.length) {
172 throw new OrekitException(OrekitMessages.OCEAN_TIDE_LOAD_DEFORMATION_LIMITS,
173 kPrime.length - 1, n, name);
174 }
175 final double termFactor = (1 + kPrime[n]) / (2 * n + 1);
176
177 // an update on IERS conventions from 2012-08-10 states that for FES model:
178 // Note that, for zonal terms, FES2004 takes the approach to set
179 // the retrograde coefficients C-f,nO and S-f,n0 to zero and to double
180 // the prograde coefficients C+f,nO and S+f,n0. Therefore, after
181 // applying Equation (6.15), the ΔCn0 have the expected value but the
182 // ΔSn0 must be set to zero.
183 // (see ftp://tai.bipm.org/iers/convupdt/chapter6/icc6.pdf)
184 final double cPlus = commonFactor * termFactor * cHatPlus * FastMath.sin(ePlus + chiF);
185 final double sPlus = commonFactor * termFactor * cHatPlus * FastMath.cos(ePlus + chiF);
186 final double cMinus = (m == 0) ? 0.0 : commonFactor * termFactor * cHatMinus * FastMath.sin(eMinus + chiF);
187 final double sMinus = (m == 0) ? 0.0 : commonFactor * termFactor * cHatMinus * FastMath.cos(eMinus + chiF);
188
189 // store parsed fields
190 addWaveCoefficients(doodson, n, m, cPlus, sPlus, cMinus, sMinus, lineNumber, line);
191
192 }
193
194 }
195 }
196 }
197 endParse();
198
199 }
200
201 }