SubFrame2.java
/* Copyright 2002-2024 Thales Alenia Space
* Licensed to CS GROUP (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.gnss.rflink.gps;
import org.hipparchus.util.FastMath;
import org.orekit.gnss.metric.parser.Units;
/**
* Container for sub-frames 2.
* <p>
* Table 20-1, sheet 2 and table 40-1, sheet 2 in
* <a href="https://navcen.uscg.gov/sites/default/files/pdf/gps/IS-GPS-200N.pdf">NAVSTAR
* GPS Space Segment/Navigation User Segment Interface</a>, IS-GPS-200N, 22 Aug 2022
* </p>
* @author Luc Maisonobe
* @since 12.0
*/
public class SubFrame2 extends SubFrame {
/** Index of IODE field. */
private static final int IODE = 7;
/** Index of Crs field. */
private static final int CRS = 8;
/** Index of Δn field. */
private static final int DELTA_N = 9;
/** Index of MO field. */
private static final int M0 = 10;
/** Index of Cuc field. */
private static final int CUC = 11;
/** Index of e field. */
private static final int E = 12;
/** Index of Cus field. */
private static final int CUS = 13;
/** Index of √a field. */
private static final int SQRT_A = 14;
/** Index of TOE field. */
private static final int TOE = 15;
/** Index of it interval field. */
private static final int FIT_INTERVAL = 16;
/** Index of AODO field. */
private static final int AODO = 17;
/** Simple constructor.
* @param words raw words
*/
SubFrame2(final int[] words) {
// create raw container
super(words, AODO + 1);
// populate container
setField(IODE, 3, 22, 8, words);
setField(CRS, 3, 6, 16, words);
setField(DELTA_N, 4, 14, 16, words);
setField(M0, 4, 6, 8, 5, 6, 24, words);
setField(CUC, 6, 14, 16, words);
setField(E, 6, 6, 8, 7, 6, 24, words);
setField(CUS, 8, 14, 16, words);
setField(SQRT_A, 8, 6, 8, 9, 6, 24, words);
setField(TOE, 10, 14, 16, words);
setField(FIT_INTERVAL, 10, 13, 1, words);
setField(AODO, 10, 8, 5, words);
}
/** Get Issue Of Data (ephemeris).
* @return Issue Of Data (ephemeris)
*/
public int getIODE() {
return getField(IODE);
}
/** Get Crs.
* @return crs (m)
*/
public double getCrs() {
return FastMath.scalb((double) getField(CRS), -5);
}
/** Get Δn.
* @return Δn (rad/s)
*/
public double getDeltaN() {
return Units.SEMI_CIRCLE.toSI(FastMath.scalb((double) getField(DELTA_N), -43));
}
/** Get M₀.
* @return M₀ (rad)
*/
public double getM0() {
return Units.SEMI_CIRCLE.toSI(FastMath.scalb((double) getField(M0), -31));
}
/** Get Cuc.
* @return Cuc (rad)
*/
public double getCuc() {
return Units.SEMI_CIRCLE.toSI(FastMath.scalb((double) getField(CUC), -29));
}
/** Get e.
* @return e
*/
public double getE() {
return FastMath.scalb((double) getField(E), -33);
}
/** Get Cus.
* @return Cus (rad)
*/
public double getCus() {
return Units.SEMI_CIRCLE.toSI(FastMath.scalb((double) getField(CUS), -29));
}
/** Get √a.
* @return d√a (√m)
*/
public double getSqrtA() {
return FastMath.scalb((double) getField(SQRT_A), -19);
}
/** Get Time Of Ephemeris.
* @return Time Of Ephemeris
*/
public int getToe() {
return getField(TOE) << 4;
}
/** Get fit interval.
* @return fit interval
*/
public int getFitInterval() {
return getField(FIT_INTERVAL);
}
/** Get Age Of data Offset.
* @return Age Of Data Offset (s)
*/
public int getAODO() {
return getField(AODO) * 900;
}
}