1. File Name
Follower-Vehicle logs are automatically generated and stored with a Universal Time Coordinated (UTC) file name. The UTC file name is formatted as
yyyy-MM-dd_hh-mm-ss_log.csv ; where:
yyyy denotes four-digit year
MM denotes two-digit month
dd denotes two-digit day
hh denotes hours (00-23)
mm denotes minutes (00-59)
ss denotes seconds (00-59)

2. Headers
At the top of the data log file, there are two headers. The first header is for Follower-Vehicle information and is described in Table I below. A second header is used to depict the Electronic Crumb (eCrumb) information for the Leader-Vehicle and is described in Table II below.

Table I – System Data Log Headers for the Follower-Vehicle
VEH                         Vehicle Identification (ID)
STATE                       Current vehicle operation state (IDLE = Operator in manual control, RUN = Autonomous mode, ROLLOUT = Ready for rollout)
NAV_STATE                   Current navigation availability state (INITIALIZING = initializing navigation, READY = navigation ready including deadreckoning, DEADRECKONING = currently deadreckoning, DEADRECKONING_MERGE = merging out of deadreckoning)
STAMP                       UTC time stamp generated by Global Positioning System (GPS) in Binary Coded Decimal (BCD format)
CRUMB                       eCrumb ID
NEXT_CRUMB                  ID of closest eCrumb to the follower vehicle
TOTAL_CRUMBS                Total number of eCrumbs in process
GPS_LAT                     GPS Latitude (degrees)
GPS_LON                     GPS Longitude (degrees)
CENTER_LAT                  GPS Center Latitude (degrees) (between 2 antennas)
CENTER_LON                  GPS Center Longitude (degrees) (between 2 antennas)
NAV_LAT                     Navigation Latitude (degrees) (including deadreckoning)
NAV_LON                     Navigation Longitude (degrees) (including deadreckoning)
GPS_S_LAT                   GPS Sensor Latitude (degrees)
GPS_S_LON                   GPS Sensor Longitude (degrees)
LATERAL_OFFSET(FT)          Current lateral offset of the follower (feet)
LATERAL_OFFSET_CMD(FT)      Commanded lateral offset of the follower (feet)
ALT                         Altitude (meters)
#SATS                       Number of satellites GPS is tracking
GPS_FIX                     GPS Fixtype (-1 = NONE, 0 = NORMAL, 1 = RTCM DIFFERENTIAL, 2 = RTK FLOAT, 3 = RTK FIXED, 5 = DEAD RECKONING, 6 = FORCED DEAD RECKONING, 9 = SBAS DIFFERENTIAL)
COURSE                      Course heading (track) (degrees)
HEADING                     Vehicle current heading (degrees)
HDG (Desired)               Desired heading (degrees); this is the heading vehicle would try to get to
VELOCITY                    Speed (miles per hour)
VEL (Desired)               Desired speed (miles per hour); target speed to get to
GAP                         Current gap (meters)
GAP (Desired)               Desired gap (meters); target gap distance to get to
CTE                         Cross track error (CTE) (meters); how far off from leader path
ACCEL                       Accelerator or brake percent (positive = acceleration, negative = braking)
STEER                       Steering turn percent (positive = turn right, negative = turn left)
NOTES                       Warnings, system errors, and other system notes (each entry ends with ###; there may be none, one, or multiple entries)

Table II – System Data Log Header for Leader-Vehicle eCrumb Information
LCB                         Vehicle ID for eCrumb (ECB = artificial eCrumbs, LDR = leader generated)
STATE                       Current vehicle operation state (IDLE = Operator in manual control, RUN = Autonomous mode, ROLLOUT = Ready for rollout)
NAV_STATE                   Current navigation availability state (INITIALIZING = initializing navigation, READY = navigation ready including deadreckoning, DEADRECKONING = currently deadreckoning, DEADRECKONING_MERGE = merging out of deadreckoning)
STAMP                       UTC time stamp generated by GPS in BCD format
CRUMB                       eCrumb ID (if this is not an eCrumb, it will be 0)
NEXT_CRUMB                  ID of closest eCrumb to the follower vehicle
TOTAL_CRUMBS                Total number of eCrumbs in process
GPS_LAT                     GPS Latitude (degrees)
GPS_LON                     GPS Longitude (degrees)
CENTER_LAT                  GPS Center Latitude (degrees) (between 2 antennas)
CENTER_LON                  GPS Center Longitude (degrees) (between 2 antennas)
NAV_LAT                     Navigation Latitude (degrees) (including deadreckoning)
NAV_LON                     Navigation Longitude (degrees) (including deadreckoning)
GPS_S_LAT                   GPS Sensor Latitude (degrees)
GPS_S_LON                   GPS Sensor Longitude (degrees)
LATERAL_OFFSET(FT)          Current lateral offset of the follower (feet)
LATERAL_OFFSET_CMD(FT)      Commanded lateral offset of the follower (feet)
ALT                         Altitude (meters)
#SATS                       Number of satellites GPS is tracking
GPS_FIX                     GPS Fixtype (-1 = NONE, 0 = NORMAL, 1 = RTCM DIFFERENTIAL, 2 = RTK FLOAT, 3 = RTK FIXED, 5 = DEAD RECKONING, 6 = FORCED DEAD RECKONING, 9 = SBAS DIFFERENTIAL)
COURSE                      Course heading (track) (degrees)
HEADING                     Vehicle current heading (degrees)
VELOCITY                    Speed (miles per hour)
