Tram's Positioning Dataset

1 README NGAP Overview Tram 1013 operating in revenue service in Florence tramway system is equipped with a set of sensors (RADAR, IMU, GNSS) and collects datasets from relevant measurements. The first and second dataset associated to NGAP system is made of the all sensors’ outputs. • RADAR: used in Doppler mode to provide information on vehicle velocity • IMU: inertial unit to measure acceleration components • GNSS: Global Navigation Satellite System to measure position NGAP system processes data from sensor with Sensor Fusion Algorithms and determines the relevant tram position. Dataset Contents/Dataset Description The first dataset is composed of the following files _slash_imu.csv _slash_RadarContinentalDataMsgPod.csv _slash_UbxNavPvtMsgPod.csv The fields description is reported in the following tables Table 1 - File _slash_imu.csv fields description (IMU sensor) Item Type Description Epoch_rosbag float64 Epoch timestamp in ns. Epoch float64 Epoch timestamp in ms. AccX float64 Acceleration along X axis expressed in m/s^2. AccY float64 Acceleration along Y axis expressed in m/s^2. AccZ float64 Acceleration along Z axis expressed in m/s^2. AngX float64 Measures the rate of rotation around the device's X-axis in degrees per second, tracking angular velocity. AngY float64 Measures the rate of rotation around the device’s Y-axis in degrees per second, tracking angular velocity. AngZ float64 Measures the rate of rotation around the device’s Z-axis in degrees per second, tracking angular velocity. Seq uint16 Sequence number used to count the received IMU messages. T uint16 Temperature in °C detected by the sensor. 2 Table 2 - _slash_RadarContinentalDataMsgPod.csv fields (RADAR) Item Type Description Epoch_bag float64 Epoch expressed in ns. Epoch Float64 Epoch expressed in ms. Speed float64 Longitudinal speed expressed in m/s (this speed is a speed provided by a Kalman Filter). Sigma float64 Sigma associated with the speed provided by the Kalman Filter. Raw Speed Float64 Raw speed that feeds the Kalman Filter (which is the mean of the speed of the clusters speed that are inside the hitbox). Innovation value Innovation value provided by the Kalman Filter. Innovation failure bool Flag which indicates if the measurement (speed) provided to the Kalman Filter has been accepted (1) or refused (0). Hitbox number uint8 Number of elements that are . Table 3 - _slash_UbxNavPvtMsgPod.csv fields (GNSS) Item Type Description epoch_s float64 Epoch expressed in ms. iTOW_ms uint32 Integer time of week in milliseconds, indicating the specifc time within the week measured from the start of the GPS week. yearUTC uint16 Represents the year part of the Coordinated Universal Time (UTC) timestamp, indicating the current year during which the IMU data is collected. monthUTC uint8 Represents the month part of the Coordinated Universal Time (UTC) timestamp, indicating the current year during which the IMU data is collected. dayUTC uint8 Represents the day part of the Coordinated Universal Time (UTC) timestamp, indicating the current year during which the IMU data is collected. hourUTC uint8 Represents the hour part of the Coordinated Universal Time (UTC) timestamp, indicating the current year during which the IMU data is collected. minUTC uint8 Represents the minutes part of the Coordinated Universal Time (UTC) timestamp, indicating the current year during which the IMU data is collected. secUTC uint8 Represents the seconds part of the Coordinated Universal Time (UTC) timestamp, indicating the current year during which the IMU data is collected. valid uint8 Flag which indicates in the Navigation message is valid or not. tAccUTC_s float64 Refers to the accuracy of the Coordinated Universal Time (UTC) timestamp in seconds, indicating the precision of the time measurement associated with the IMU data. nano_ns int32 Refers to the nanosecond prt of the timestamp, indicating the fractional second precision of the time measurement associated with the IMU data. fixTypeGNSS uint8 Refers to the type of positioning fix determined by the GNSS, indicating the level of accuracy and reliability of the location (e.g., no fix, 2D fix, 3 fix). flags uint8 Refers specific Ublox configuration flags. reserved uint8 Reserved flag. 3 numSV uint8 Number of satellities received signals. longitude_rad float64 Acquired longitude in radians. latitude_rad float64 Acquired latitude in radians. heightEllipsoid_m float64 Refers to the height above the ellipsoid model of the Earth in meters, indicating the vertical position relative to a mathematical model rather than mean sea level. heightMSL_m float64 Refers to the altitude in meters of the device relative to the Earth's ellipsoid, a mathematical figure approximating the shape of the Earth. hAcc_m float64 Refers to the horizontal accuracy in meters, indicating the estimated precision of the horizontal position measurements provided by IMU. vAcc_m float64 Refers to the vertical accuracy in meters, indicating the estimated precision of the vertical position measurements provided by IMU. velN_m_s float64 Refers to the velocity North direction measured in meters per second, indicating the northward component of the velocity vector captured by the IMU. velE_m_s float64 Refers to the velocity in the East direction measured in meters per second, indicating the eastward component of the velocity vector captured by the IMU. velD_m_s float64 Refers to the velocity in the Down direction measured in meters per second, indicating the downward component of the velocity vector captured by the IMU. groundSpeed_m_s float64 Ground speed calculate by the received expressed in m/s. heading_rad float64 Orientation angle in radians relative to the North, indicating the direction in which the device is facing. speedAcc_m_s float64 Ground speed accuracy in m/s. headingAcc_rad float64 Orientation angle accuracy expressed in radians. positionDOP float64 Refers to the Position Dilution of Precision, a measure of the error in position due to the geometric positions of the satellites being tracked. reserved16 uint16 Reserved. reserved32 uint32 Reserved. headVeh_deg int32 Refers to the vehicle's heading in degrees, indicating the direction in which the vehicle is moving, relative to true North. magDec_deg int16 Refers to the magnetic declination in degrees, indicating the angle between magnetic North and the true North at the location of the IMU. magAcc_deg uint16 Refers to the accuracy of the magnetic heading measurement in degrees, indicating the expected error range in the magnetic declination reading. The second dataset is composed of the following files output.csv. The fields description is reported in the following tables. Table 4 Output.csv field description Item Type Description EPOCH Epoch of when the message has been received by the SFA (by the listener module) SENSOR Identifier of the received message: o 1: Acceleration and angular velocity coming from IMU 4 o 3: Speed message coming from RADAR o 9: Initialization message o 12: Balise position message coming from the GNSS Navigation message ImuCnt Sequence counter of the IMU message. Important in order to check if we are missing some IMU messages. Dropped Flag which indicates if IMU message have been dropped (1) or not (0). GT_cnt Not Applicable GT_Edge Identification of the spline where the SFA is running. GT_Position Initial position in [m] specified by the initialization message. GT_Speed Initial speed in [m/s] specified by the initialization message. GT_Dir Direction of the vehicle on the spline. 0 means forward direction, 1 means backward direction. FU_cnt Counter which is used the number of predictions processed by the SFA. FU_Edge Identifier of the spline used by the SFA. FU_Arc Position, starting from the origin of the spline, in [m] of the vehicle on the used spline FU_Arc_var Variance of the position, calculated by the SFA, expressed in 𝑚𝑚 2 . FU_Arc_norm Position, starting from the end of the spline, in [m] of the vehicle on the used spline FU_Protection_Limit_speed Speed Protection Limit value exiting the SFA, expressed in m/s. FU_Protection_Limit_position Position Protection Limit value exiting the SFA, expressed in m. FU_Speed Speed, expressed in m/s, calculated by the SFA. FU_SpeedVar Variance of the speed, expressed in 𝑚𝑚 2 𝑠𝑠 2 calculated by the SFA. FU_Epoch Epoch of the Sensor Fusion Algorithm. FU_ecef_x ECEF X coordinate, associated to the position calculated by the SFA on the selected spline. FU_ecef_y ECEF Y coordinate, associated to the position calculated by the SFA on the selected spline. FU_ecef_z ECEF Z coordinate, associated to the position calculated by the SFA on the selected spline. FU_vel_x Speed along X axis, expressed in [m/s], calculated by the SFA. FU_vel_y Speed along Y axis, expressed in [m/s], calculated by the SFA. FU_vel_z Speed along Z axis, expressed in [m/s], calculated by the SFA. FU_dir_x Direction along X axis, calculated by the SFA: 0-forward, 1-backward. FU_dir_y Direction along Y axis, calculated by the SFA: 0-forward, 1-backward. FU_dir_z Direction along Z axis, calculated by the SFA: 0 -forward, 1-backward. 5 Sigma Speed sigma value, expressed in [m/s], provided by the RADAR. Speed Speed value, expressed in [m/s], provided by the RADAR. SequenceNum Incremental number which from 1 to 32767 which is used to identify if we are missing an IMU packet or not, BitStatus Flag which is used to identify if the IMU it has been correctly processing IMU information 0 or there was a problem 0. X1SpecForce Acceleration along x expressed in 𝑚𝑚 𝑠𝑠 2, provided by the IMU. X2SpecForce Acceleration along y expressed in 𝑚𝑚 𝑠𝑠2, provided by the IMU. X3SpecForce Acceleration along z expressed in 𝑚𝑚 𝑠𝑠2, provided by the IMU X1AngVel Angular velocity along x expressed in ° 𝑠𝑠, provided by the IMU. X2AngVel Angular velocity along x expressed in ° 𝑠𝑠, provided by the IMU. X3AngVel Angular velocity along x expressed in ° 𝑠𝑠, provided by the IMU X1MagField Magnetometer force along x expressed in Gauss, provided by the IMU. X2MagField: Magnetometer force along y expressed in Gauss, provided by the IMU. mX3MagField Magnetometer force along z expressed in Gauss, provided by the IMU. GPSLatitude Latitude calculated by the GNSS receiver, expressed in m. This information is received when the GNSS NAV message is provided GPSLongitude Longitude calculated by the GNSS receiver, expressed in m. This information is received when the GNSS NAV message is provided. GPSAltitude Altitude calculated by the GNSS receiver, expressed in m. This information is received when the GNSS NAV message is provided. GPSSpeed Speed calculated by the GNSS receiver, expressed in m/s. This information is received when the GNSS NAV message is provided. HAccuracy Horizontal accuracy expressed in m of the position provided as latitude, longitude, altitude. This information is received when the GNSS NAV message is provided. VAccuracy Vertical accuracy expressed in m of the position provided as latitude, longitude, altitude. This information is received when the GNSS NAV message is provided. ArcLengthGNSS Arclength value (spline distance from origin) of the projected GNSS coordinates. Pos_accuracy Horizontal accuracy, expressed in [m] provided by the GNSS receiver. NumSatellities Number of satellites of the received position message. This information is received when the GNSS NAV message is provided. Instead, the dataset related to velocity contains the following file profilo_velocità.csv. The following table describes the field meaning 6 Table 5File profilo_velocità.csv fields description Item Type Description ArcLenght Length of arc of spline which approximates the railway line (m). The difference between two adjacent samples is very short, usually of a magnitude of 10 -4 m. The first sample start around 16 meters (approximately half of the length of tram) and ends at 11.15 km which is the length of Line T1. FU_Speed Velocity (m/s) ECEF_X Coordinate ECEF X (m) ECEF_Y Coordinate ECEF Y (m) ECEF_Z Coordinate ECEF Z (m) FU_Speed_X Velocity X (m/s) FU_Speed_Y Velocity Y (m/s) FU_Speed_Z Velocity Z (m/s) Getting Started The dataset is provided in .csv format, so no special software or prerequisites are required to access or use it. Download & Usage • git clone https://github.com/VERGE-PROJECT/GTSI-HITACHI-NGAP-dataset The files are zipped, divided per folder and, because github limitation (file size less than 25MB), splitted in several files. Citation NA