Incorrect trajectory generation from JSON configuration

[Hsymbol-511]

1、When initVelocity type is set to SCU, the course angle is calculated incorrectly.
2、In the JSON, "speedUnit": "kph" with "speed": 741.6 (which should be ≈ 206 m/s) is directly treated as 741.6 m/s.

I wanted to analyze the error between the software receiver's positioning solution and the true trajectory. I generated a trajectory using MATLAB according to the JSON configuration, but found that the trajectory I generated seems to differ greatly from the receiver's solved trajectory, and that's how I discovered these problems.

I also added extra trajectory output to the tag file. The original course angle of 325° became 261°, which caused the latitude/longitude that should be heading northwest to become heading southwest.

The receiver's solution also confirmed this: the computed speed was 2667 km/h, which is exactly 3.6 times the value configured in the JSON.

I would also like to know what unit is assumed for the up velocity when configured this way.Although I've already worked around these two issues by modifying the code, I'm not confident that my fix is correct. Looking forward to your proper fix.

[Hsymbol-511]

MATLAB：
lon = trace.Longitude(idx);
lat = trace.Latitude(idx);
alt = trace.Height(idx); % 高度单位：米
speed_kph = trace.Speed(idx); % 速度单位：km/h
speed_up = trace.Speed_up(idx); % 速度单位：m/s
course_deg = trace.Angle(idx); % 航向角（度）

% 参数与 JSONConfig 一致
duration_sec = 15; % trajectoryList 中 Const time = 15
dt = 0.1; % 1ms 步长
num_steps = round(duration_sec / dt);

% 初始位置（LLA -> ECEF）
initLLA = [lat, lon, alt];            
initPos = lla2ecef(initLLA);          % 返回 1x3

% 初始速度转换
speed_mps = speed_kph * 1000 / 3600;  
course_rad = deg2rad(course_deg);
vn = speed_mps * cos(course_rad);     % 北向速度
ve = speed_mps * sin(course_rad);     % 东向速度
vu = speed_up;                      

% ENU -> ECEF 旋转矩阵
lat_rad = deg2rad(lat);
lon_rad = deg2rad(lon);
R = [-sin(lon_rad), -sin(lat_rad)*cos(lon_rad), cos(lat_rad)*cos(lon_rad);
     cos(lon_rad),  -sin(lat_rad)*sin(lon_rad), cos(lat_rad)*sin(lon_rad);
     0,              cos(lat_rad),              sin(lat_rad)];

initVel = (R * [ve; vn; vu])';        

% 生成参考轨迹
refTime = (0:num_steps-1)' * dt;      
refPosECEF = zeros(num_steps, 3);     
refLLA = zeros(num_steps, 3);

for i = 1:num_steps
    t = refTime(i);
    pos = initPos + initVel * t;
    refPosECEF(i, :) = pos;
    
   
    lla = ecef2lla(pos);
    refLLA(i,1) = lla(1);   % lat
    refLLA(i,2) = lla(2);   % lon
    refLLA(i,3) = lla(3);   % alt
end