Heading

Real Time GPS or GNSS Heading Determination:

• Two GNSS antennas generate a vector in space that has both horizontal (azimuth) and vertical (pitch or roll) components
• Heading and pitch/roll solutions between the antennas are computed using our ALIGN^® heading engine
• ALIGN's heading accuracy is a function of the horizontal separation between the two antennas

Real Time SPAN^® GPS/INS or GNSS/INS Heading Determination:

• A SPAN system typically consists of one antenna, one GNSS receiver and also one Inertial Measurement Unit (IMU). Dual antenna SPAN GPS/INS systems are also available to enhance initialization time and long term stability of the system
• In a SPAN system, heading (and roll and pitch) is computed using gyroscope data, accelerometer data (IMU) and GNSS data
• Heading accuracy of a SPAN system is based on the accelerometer and gyroscope specification of the IMU being used and the type of motion encountered

Post-processed Heading Solutions:

• Two GNSS receivers' raw code and phase data can be post-processed in our GrafMov to obtain heading measurements
• A GNSS receiver's raw code and phase data plus IMU raw measurements can be post-processed in Inertial Explorer to obtain roll, pitch and yaw measurements. The forward post-processed solution will be similar to the real-time SPAN system mentioned above
• Our GrafMov or Inertial Explorer post-processing software takes advantage of both forward and backward data computations to generate the most accurate combined solution. This is especially useful for data collected under challenging GNSS environments (i.e., signal blockages, multipath, etc.)

When choosing a heading solution, consider the following needs of your application:

• Solution accuracy
• Signal availability
• Solution rate
• Continuity of solution updates
• Type of motion
• System exportability
• System price
• System installation constraints
• Real-time versus post-processed solution