Precision Attitude Sensing on Aerostats (PASA)

"Archangel's Air Data Attitude Heading Reference System (ADAHRS) is a solid-state unit that integrates low-cost piezoelectric MEMS gyros and accelerometers, as well as pitot and static sensing devices and a magnetometer with a local processor. Accuraciesto 1 degree RMS have been demonstrated in aircraft test flights. The gyro sensors used in the construction of the ADAHRS were low cost without reproducible thermal profiles. All drift in the ADAHRS is therefore estimated on line using a proprietarytechnique called FLASP (Fuzzy Logic Adaptive Signal Processing). By replacing the existing gyro sensors with the new sensors and modifying the FLASP algorithm, the RMS attitude errors can be significantly reduced.Following this approach, the RMS accuracies for pitch and roll can be under 0.10 degree (1.75 m radian). With these accuracies in pitch and roll, heading accuracies can be under 0.15 degree. With the greater accuracies, the ADAHRS can be used for attitudedetermination of tethered and high-altitude aerostats. The attitude solution is extremely important for pinpointing the location and velocity of radar returns. With an overall RSS attitude accuracy of approximately 0.21 degree, location of returns can bedetermined to a RMS accuracy of 266 meters at a 100 km range. Existing ADAHRS products typically sell for $22,000 to $30,000. The Archangel ADAHRS is sold in quantities of one for only $8,000. By increasing the accuracy of the A