SubFrameAlmanac.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 5, page 1-24.
- * <p>
- * Table 20-1, sheet 4 and table 40-1, sheet 4 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 SubFrameAlmanac extends SubFrame45 {
- /** Index of e field. */
- private static final int E = 9;
- /** Index of TOA field. */
- private static final int TOA = 10;
- /** Index of δi field. */
- private static final int DELTA_I = 11;
- /** Index of dot(Ω) field. */
- private static final int OMEGA_DOT = 12;
- /** Index of SV health field. */
- private static final int SV_HEALTH = 13;
- /** Index of √a field. */
- private static final int SQRT_A = 14;
- /** Index of Ω₀ field. */
- private static final int UPPERCASE_OMEGA_0 = 15;
- /** Index of ω field. */
- private static final int LOWERCASE_OMEGA = 16;
- /** Index of M₀ field. */
- private static final int M0 = 17;
- /** Index of AF0 field. */
- private static final int AF0 = 18;
- /** Index of AF1 field. */
- private static final int AF1 = 19;
- /** Simple constructor.
- * @param words raw words
- */
- SubFrameAlmanac(final int[] words) {
- // create raw container
- super(words, AF1 + 1);
- // populate container
- setField(E, 3, 6, 16, words);
- setField(TOA, 4, 22, 8, words);
- setField(DELTA_I, 4, 6, 16, words);
- setField(OMEGA_DOT, 5, 14, 16, words);
- setField(SV_HEALTH, 5, 6, 8, words);
- setField(SQRT_A, 6, 6, 24, words);
- setField(UPPERCASE_OMEGA_0, 7, 6, 24, words);
- setField(LOWERCASE_OMEGA, 8, 6, 24, words);
- setField(M0, 9, 6, 24, words);
- setField(AF0, 10, 22, 8, 10, 8, 3, words);
- setField(AF1, 10, 11, 11, words);
- }
- /** Get the PRN code phase of the SV.
- * @return PRN code phase
- */
- public int getPRN() {
- // sub-frames that contain almanacs use the SV-ID for the PRN
- return getSvId();
- }
- /** Get eccentricity.
- * @return eccentricity
- */
- public double getE() {
- return FastMath.scalb((double) getField(E), -21);
- }
- /** Get Time Of Almanac.
- * @return Time Of Almanac (seconds)
- */
- public int getToaA() {
- return getField(TOA) << 12;
- }
- /** Get Δi.
- * @return Δi (rad)
- */
- public double getDeltai() {
- return Units.SEMI_CIRCLE.toSI(FastMath.scalb((double) getField(DELTA_I), -19));
- }
- /** Get dot(Ω).
- * @return dot(Ω) (rad/s)
- */
- public double getOmegaDot() {
- return Units.SEMI_CIRCLE.toSI(FastMath.scalb((double) getField(OMEGA_DOT), -38));
- }
- /** Get SV health.
- * @return SV health
- */
- public int getSvHealth() {
- return getField(SV_HEALTH);
- }
- /** Get √a.
- * @return d√a (√m)
- */
- public double getSqrtA() {
- return FastMath.scalb((double) getField(SQRT_A), -11);
- }
- /** Get Ω₀.
- * @return Ω₀ (rad)
- */
- public double getUppercaseOmega0() {
- return Units.SEMI_CIRCLE.toSI(FastMath.scalb((double) getField(UPPERCASE_OMEGA_0), -23));
- }
- /** Get ω.
- * @return ω(rad)
- */
- public double getLowercaseOmega() {
- return Units.SEMI_CIRCLE.toSI(FastMath.scalb((double) getField(LOWERCASE_OMEGA), -23));
- }
- /** Get M₀.
- * @return M₀ (rad)
- */
- public double getM0() {
- return Units.SEMI_CIRCLE.toSI(FastMath.scalb((double) getField(M0), -23));
- }
- /** Get af₀.
- * @return af₀ (second)
- */
- public double getAF0() {
- return FastMath.scalb((double) getField(AF0), -20);
- }
- /** Get af₁.
- * @return af₁ (second/second)
- */
- public double getAF1() {
- return FastMath.scalb((double) getField(AF1), -38);
- }
- }