1 /* Copyright 2022-2025 Thales Alenia Space
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.gnss.rflink.gps;
18
19 import org.hipparchus.util.FastMath;
20 import org.orekit.gnss.metric.parser.Units;
21
22 /**
23 * Container for sub-frames 3.
24 * <p>
25 * Table 20-1, sheet 3 and table 40-1, sheet 3 in
26 * <a href="https://navcen.uscg.gov/sites/default/files/pdf/gps/IS-GPS-200N.pdf">NAVSTAR
27 * GPS Space Segment/Navigation User Segment Interface</a>, IS-GPS-200N, 22 Aug 2022
28 * </p>
29 * @author Luc Maisonobe
30 * @since 12.0
31 */
32 public class SubFrame3 extends SubFrame {
33
34 /** Index of Cic field. */
35 private static final int CIC = 7;
36
37 /** Index of Ω₀ field. */
38 private static final int UPPERCASE_OMEGA_0 = 8;
39
40 /** Index of Cis field. */
41 private static final int CIS = 9;
42
43 /** Index of i₀ field. */
44 private static final int I0 = 10;
45
46 /** Index of Crc field. */
47 private static final int CRC = 11;
48
49 /** Index of ω field. */
50 private static final int LOWERCASE_OMEGA = 12;
51
52 /** Index of dot(Ω) field. */
53 private static final int OMEGA_DOT = 13;
54
55 /** Index of IODE field. */
56 private static final int IODE = 14;
57
58 /** Index of dot(i) field. */
59 private static final int I_DOT = 15;
60
61 /** Simple constructor.
62 * @param words raw words
63 */
64 SubFrame3(final int[] words) {
65
66 // create raw container
67 super(words, I_DOT + 1);
68
69 // populate container
70 setField(CIC, 3, 14, 16, words);
71 setField(UPPERCASE_OMEGA_0, 3, 6, 8, 4, 6, 24, words);
72 setField(CIS, 5, 14, 16, words);
73 setField(I0, 5, 6, 8, 6, 6, 24, words);
74 setField(CRC, 7, 14, 16, words);
75 setField(LOWERCASE_OMEGA, 7, 6, 8, 8, 6, 24, words);
76 setField(OMEGA_DOT, 9, 6, 24, words);
77 setField(IODE, 10, 22, 8, words);
78 setField(I_DOT, 10, 8, 14, words);
79
80 }
81
82 /** Get Cic.
83 * @return Cic (rad)
84 */
85 public double getCic() {
86 return FastMath.scalb((double) getField(CIC), -29);
87 }
88
89 /** Get Ω₀.
90 * @return Ω₀ (rad)
91 */
92 public double getUppercaseOmega0() {
93 return Units.SEMI_CIRCLE.toSI(FastMath.scalb((double) getField(UPPERCASE_OMEGA_0), -31));
94 }
95
96 /** Get Cis.
97 * @return Cis (rad)
98 */
99 public double getCis() {
100 return FastMath.scalb((double) getField(CIS), -29);
101 }
102
103 /** Get i₀.
104 * @return i₀ (rad)
105 */
106 public double getI0() {
107 return Units.SEMI_CIRCLE.toSI(FastMath.scalb((double) getField(I0), -31));
108 }
109
110 /** Get Crc.
111 * @return Crc (rad)
112 */
113 public double getCrc() {
114 return FastMath.scalb((double) getField(CRC), -5);
115 }
116
117 /** Get ω.
118 * @return ω(rad)
119 */
120 public double getLowercaseOmega() {
121 return Units.SEMI_CIRCLE.toSI(FastMath.scalb((double) getField(LOWERCASE_OMEGA), -31));
122 }
123
124 /** Get dot(Ω).
125 * @return dot(Ω) (rad/s)
126 */
127 public double getOmegaDot() {
128 return Units.SEMI_CIRCLE.toSI(FastMath.scalb((double) getField(OMEGA_DOT), -43));
129 }
130
131 /** Get Issue Of Data (ephemeris).
132 * @return Issue Of Data (ephemeris)
133 */
134 public int getIODE() {
135 return getField(IODE);
136 }
137
138 /** Get dot(i).
139 * @return dot(i) (rad/s)
140 */
141 public double getIDot() {
142 return Units.SEMI_CIRCLE.toSI(FastMath.scalb((double) getField(I_DOT), -43));
143 }
144
145 }