osgearth3.2根据TLE参数绘制卫星轨道的代码

要在osgEarth 3.2中根据TLE参数绘制卫星轨道，你可以使用以下代码片段：

#include <iostream>
#include <fstream>
#include <string>
#include <sstream>
#include <iomanip>
#include <cmath>
#include <osgEarth/MapNode>
#include <osgEarthUtil/Controls>
#include <osgEarthUtil/EarthManipulator>
#include <osgEarthUtil/Sky>
#include <osgEarthUtil/ExampleResources>
#include <osgEarthAnnotation/FeatureNode>
#include <osgEarthSymbology/Style>
#include <osgEarthDrivers/tms/TMSOptions>
#include <osgEarthDrivers/wms/WMSOptions>
#include <osgEarthDrivers/feature_ogr/OGRFeatureOptions>
#include <osgEarthFeatures/Feature>
#include <osgEarthFeatures/FeatureModelLayer>
#include <osgEarthUtil/Controls>
#include <osgEarthUtil/ActivityMonitorTool>
#include <osgEarthUtil/RTTPicker>
#include <osgEarthUtil/MouseCoordsTool>
#include <osgEarthUtil/EarthManipulator>
#include <osgEarthUtil/ViewFitter>
#include <osgEarthUtil/ExampleResources>

using namespace osgEarth;
using namespace osgEarth::Features;
using namespace osgEarth::Symbology;
using namespace osgEarth::Util;
using namespace osgEarth::Annotation;

// 用于将字符串转换为浮点数的函数
double to_double(const std::string& str)
{
    std::istringstream ss(str);
    double value;
    ss >> value;
    return value;
}

// 用于将时间字符串转换为时间戳的函数
time_t to_time_t(const std::string& time_str)
{
    std::tm timeinfo = {};
    std::istringstream ss(time_str);
    ss >> std::get_time(&timeinfo, "%Y-%m-%d %H:%M:%S");
    return std::mktime(&timeinfo);
}

// 计算卫星在给定时间的位置
osg::Vec3d calculate_satellite_position(double time_since_epoch, double inclination,
    double ascending_node_longitude, double eccentricity, double argument_of_perigee,
    double mean_anomaly, double semi_major_axis)
{
    // 计算卫星轨道上的平均角速度
    double mean_motion = 2.0 * osg::PI / (86400.0 / mean_anomaly);

    // 计算卫星在给定时间的平均角度
    double mean_angle = mean_anomaly + mean_motion * time_since_epoch;

    // 计算卫星在给定时间的偏心率角
    double eccentric_anomaly = mean_angle;
    for (int i = 0; i < 10; i++) {
        double delta = (eccentric_anomaly - eccentricity * sin(eccentric_anomaly) - mean_angle) /
            (1.0 - eccentricity * cos(eccentric_anomaly));
        eccentric_anomaly -= delta;
        if (fabs(delta) < 1e-12) {
            break;
        }
    }

    // 计算卫星在给定时间的真近点角
    double true_anomaly = 2.0 * atan(sqrt((1.0 + eccentricity) / (1.0 - eccentricity)) *
        tan(0.5 * eccentric_anomaly));

    // 计算卫星在给定时间的升交点经度
    double raan = ascending_node_longitude * osg::PI / 180.0;
    double arg_perigee = argument_of_perigee * osg::PI / 180.0;
    double inclination_rad = inclination * osg::PI / 180.0;
    double x = semi_major_axis * (cos(raan) * cos(true_anomaly + arg_perigee) -
        sin(raan) * sin(true_anomaly + arg_perigee) * cos(inclination_rad));
    double y = semi_major_axis * (sin(raan) * cos(true_anomaly + arg_perigee) +
        cos(raan) * sin(true_anomaly + arg_perigee) * cos(inclination_rad));
    double z = semi_major_axis * sin(true_anomaly + arg_perigee) * sin(inclination_rad);

    return osg::Vec3d(x, y, z);
}

int main(int argc, char** argv)
{
    // 读取TLE文件
    std::ifstream tle_file("tle.txt");
    if (!tle_file.is_open()) {
        std::cerr << "Failed to open TLE file!" << std::endl;
        return -1;
    }

    // 读取第一行TLE参数
    std::string line1;
    std::getline(tle_file, line1);

    // 读取第二行TLE参数
    std::string line2;
    std::getline(tle_file, line2);

    // 解析TLE参数
    std::string name = line1.substr(0, 24);
    double inclination = to_double(line2.substr(8, 8));
    double ascending_node_longitude = to_double(line2.substr(17, 8));
    double eccentricity = to_double("0." + line2.substr(26, 7));
    double argument_of_perigee = to_double(line2.substr(34, 8));
    double mean_anomaly = to_double(line2.substr(43, 8));
    double mean_motion = to_double(line2.substr(52, 11));
    double semi_major_axis = pow(398600.4418 / pow(mean_motion, 2), 1.0 / 3.0) * 1000.0;

    // 创建地球模型
    osgViewer::Viewer viewer;
    osg::ref_ptr<osgEarth::MapNode> mapNode = osgEarth::Util::MapNodeHelper().load(arguments, &viewer);
    viewer.setSceneData(mapNode);

    // 计算卫星在当前时间的位置
    double time_since_epoch = difftime(time(0), to_time_t("2022-01-01 00:00:00"));
    osg::Vec3d satellite_position = calculate_satellite_position(time_since_epoch, inclination,
        ascending_node_longitude, eccentricity, argument_of_perigee, mean_anomaly, semi_major_axis);

    // 创建轨道线段的几何体
    osg::ref_ptr<osg::Vec3Array> vertices = new osg::Vec3Array;
    vertices->push_back(osg::Vec3d(0, 0, 0));
    vertices->push_back(satellite_position);
    osg::ref_ptr<osg::Geometry> geometry = new osg::Geometry;
    geometry->setVertexArray(vertices.get());
    geometry->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::LINE_STRIP, 0, 2));

    // 创建轨道线段的节点
    osg::ref_ptr<Feature> feature = new Feature(geometry.get(), mapNode->getMapSRS(), Feature::UNDEFINED);
    osg::ref_ptr<FeatureNode> featureNode = new FeatureNode(mapNode, feature.get());

    // 添加轨道线段节点到地球上
    mapNode->addChild(featureNode.get());

    viewer.run();
    return 0;
}

这段代码使用 osgEarth 库创建了一个地球模型，并使用TLE参数计算了卫星在当前时间的位置，并在地球上绘制了一条卫星轨道线。你可以根据自己的需要修改TLE文件路径，调整轨道的位置和方向。