{
  "schema_version": 3,
  "transform_convention": "T_A_B maps a point in frame B into frame A: p_A = T_A_B * p_B",
  "frames": {
    "world": {
      "name": "W",
      "axes": {
        "x": "East",
        "y": "North",
        "z": "Up"
      },
      "origin_llh_gga": {
        "latitude_deg": 30.449400235285786,
        "longitude_deg": 114.51175649447971,
        "altitude_m": 30.877709330727896
      }
    },
    "vehicle": {
      "name": "V",
      "axes": {
        "x": "forward",
        "y": "left",
        "z": "up"
      },
      "origin": "ground level, centre of the four wheels"
    },
    "uav": {
      "name": "U",
      "axes": {
        "x": "forward",
        "y": "left",
        "z": "up"
      }
    }
  },
  "extrinsics_m": {
    "uav_rtk_antenna_in_u": [
      0.03,
      -0.05,
      0.25
    ],
    "car_rtk_antenna_in_v": [
      0.01,
      -0.22,
      0.86
    ]
  },
  "transforms": {
    "T_W_V": {
      "vehicle_pose_0716": [
        [
          -0.3400029448603845,
          -0.9404243709550845,
          0.0,
          0.19553638681993726
        ],
        [
          0.9404243709550845,
          -0.3400029448603845,
          0.0,
          -0.14374656836228367
        ],
        [
          0.0,
          0.0,
          1.0,
          -1.124236942068264
        ],
        [
          0.0,
          0.0,
          0.0,
          1.0
        ]
      ],
      "vehicle_pose_0723": [
        [
          -0.344470843811927,
          -0.9387970162732192,
          0.0,
          0.0
        ],
        [
          0.9387970162732192,
          -0.344470843811927,
          0.0,
          0.0
        ],
        [
          0.0,
          0.0,
          1.0,
          -1.22
        ],
        [
          0.0,
          0.0,
          0.0,
          1.0
        ]
      ]
    }
  },
  "sensor_extrinsics": {
    "_comment_en": "Per-sensor extrinsics used by the real-time pipeline. Values are identical to the source repository config/extrinsic_calibration.json and document/外参标定结果.txt (paper-form). Kinematic chain: T_W_L = T_W_V * T_V_G1(yaw) * T_G1_G2(pitch) * T_G2_L.",
    "_comment_zh": "实时系统使用的传感器外参。数值与源码仓库 config/extrinsic_calibration.json 及 document/外参标定结果.txt（论文公式版）一致。运动学链：T_W_L = T_W_V · T_V_G1(yaw) · T_G1_G2(pitch) · T_G2_L。",
    "frames": {
      "V": "Vehicle (origin: ground level, centre of four wheels; x=forward, y=left, z=up) / 车辆坐标系（原点：地面四轮中心；x 前、y 左、z 上）",
      "H": "RoboSense RS-Helios LiDAR (used for vehicle localization) / Helios 雷达坐标系（用于车辆定位）",
      "G1": "Gimbal yaw (pan) joint frame / 云台偏航（pan）关节坐标系",
      "G2": "Gimbal pitch (tilt) joint frame / 云台俯仰（tilt）关节坐标系",
      "L": "RoboSense RS-M1 LiDAR (tracking sensor) / M1 雷达坐标系（追踪传感器）",
      "C": "Hikvision camera / 相机坐标系",
      "R": "Vehicle RTK antenna / 车载 RTK 天线"
    },
    "encoder_to_angle": {
      "_comment_en": "Maps servo encoder readings to joint angles (degrees). E_pan, E_tilt are the raw encoder codes.",
      "_comment_zh": "舵机编码值到关节角度（度）的映射。E_pan、E_tilt 为原始编码值。",
      "pan_deg": "0.0669 * (E_pan - 2062.8)",
      "tilt_deg": "-0.071 * (E_tilt - 1936.79)"
    },
    "T_V_G1": {
      "_comment_en": "Pan (yaw) joint pose in Vehicle. Time-varying rotation Rz(yaw). / 偏航关节在车辆坐标系中的位姿，时变旋转 Rz(yaw)。",
      "rotation_param": "Rz(yaw)",
      "translation": [
        0.18,
        0.0,
        0.85
      ]
    },
    "T_G1_G2": {
      "_comment_en": "Tilt (pitch) joint pose in G1. Time-varying rotation Ry(pitch). / 俯仰关节在 G1 坐标系中的位姿，时变旋转 Ry(pitch)。",
      "rotation_param": "Ry(pitch)",
      "translation": [
        0.0,
        0.0,
        0.062
      ]
    },
    "T_G2_L": {
      "_comment_en": "RS-M1 LiDAR pose in G2. Pure translation, identity rotation. / M1 雷达在 G2 坐标系中的位姿，纯平移，无旋转。",
      "matrix_4x4": [
        [
          1.0,
          0.0,
          0.0,
          0.018
        ],
        [
          0.0,
          1.0,
          0.0,
          0.0
        ],
        [
          0.0,
          0.0,
          1.0,
          0.072
        ],
        [
          0.0,
          0.0,
          0.0,
          1.0
        ]
      ]
    },
    "T_G2_C": {
      "_comment_en": "Camera pose in G2. Rotation = ideal axis permutation left-multiplied by Ry(+1.10 deg) fine correction. / 相机在 G2 坐标系中的位姿。旋转在理想轴置换基础上左乘 Ry(+1.10°) 精修。",
      "matrix_4x4": [
        [
          0.0,
          -0.0191974424,
          0.999815712122,
          0.025
        ],
        [
          -1.0,
          0.0,
          0.0,
          0.08
        ],
        [
          0.0,
          -0.999815712122,
          -0.0191974424,
          0.058
        ],
        [
          0.0,
          0.0,
          0.0,
          1.0
        ]
      ]
    },
    "T_V_H": {
      "_comment_en": "RS-Helios LiDAR pose in Vehicle. Pure translation, identity rotation. / Helios 雷达在车辆坐标系中的位姿，纯平移，无旋转。",
      "matrix_4x4": [
        [
          1.0,
          0.0,
          0.0,
          -0.17
        ],
        [
          0.0,
          1.0,
          0.0,
          0.0
        ],
        [
          0.0,
          0.0,
          1.0,
          0.95
        ],
        [
          0.0,
          0.0,
          0.0,
          1.0
        ]
      ]
    },
    "T_V_R": {
      "_comment_en": "Vehicle RTK antenna pose in Vehicle. Heading aligned with Vehicle. / 车载 RTK 天线在车辆坐标系中的位姿，朝向与车辆一致。",
      "matrix_4x4": [
        [
          1.0,
          0.0,
          0.0,
          0.01
        ],
        [
          0.0,
          1.0,
          0.0,
          -0.22
        ],
        [
          0.0,
          0.0,
          1.0,
          0.86
        ],
        [
          0.0,
          0.0,
          0.0,
          1.0
        ]
      ]
    },
    "camera_intrinsic": {
      "_comment_en": "Hikvision MV-CS050-10UC pinhole + radial-tangential distortion. / 海康 MV-CS050-10UC 相机内参 + 径向切向畸变。",
      "fx": 2292.4112472233305,
      "fy": 2289.1280016360388,
      "cx": 1183.4111483043127,
      "cy": 1038.7331036789315,
      "k1": -0.08272229239611316,
      "k2": 0.13203832389665585,
      "p1": 0.0003186630393428523,
      "p2": -0.0032283162603578613,
      "k3": -0.11291916041136751,
      "image_width": 2448,
      "image_height": 2048
    }
  }
}