1 /*
2  * Copyright (c) 2021 Huawei Device Co., Ltd.
3  * Licensed under the Apache License, Version 2.0 (the "License");
4  * you may not use this file except in compliance with the License.
5  * You may obtain a copy of the License at
6  *
7  *     http://www.apache.org/licenses/LICENSE-2.0
8  *
9  * Unless required by applicable law or agreed to in writing, software
10  * distributed under the License is distributed on an "AS IS" BASIS,
11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12  * See the License for the specific language governing permissions and
13  * limitations under the License.
14  */
15 
16 #ifndef GEOMAGNETIC_FIELD_H
17 #define GEOMAGNETIC_FIELD_H
18 
19 #include <cstdint>
20 #include <vector>
21 
22 class GeomagneticField {
23 public:
24     GeomagneticField(float latitude, float longitude, float altitude, int64_t timeMillis);
25     ~GeomagneticField() = default;
26     float ObtainX();
27     float ObtainY();
28     float ObtainZ();
29     float ObtainGeomagneticDip();
30     float ObtainDeflectionAngle();
31     float ObtainLevelIntensity();
32     float ObtainTotalIntensity();
33 
34 private:
35     std::vector<std::vector<float>> GetSchmidtQuasiNormalFactors(int32_t expansionDegree);
36     void CalculateGeomagneticComponent(double latDiffRad, int64_t timeMillis);
37     void GetLongitudeTrigonometric();
38     void GetRelativeRadiusPower();
39     void CalibrateGeocentricCoordinates(float latitude, float longitude, float altitude);
40     void InitLegendreTable(int32_t expansionDegree, float thetaRad);
41     double ToDegrees(double angrad);
42     double ToRadians(double angdeg);
43 };
44 #endif // GEOMAGNETIC_FIELD_H