{
  "$type": "site.standard.document",
  "description": "Techniques are provided to determine an initial quaternion transform that is used to transform measurements received from accelerometer, rate sensor and inertial reference subsystems from a vehicle coordinate frame to an inertial navigation frame. Methods disclosed determine corrective angular…",
  "path": "/patents/1000671",
  "publishedAt": "2012-07-04T00:00:00.000Z",
  "site": "at://did:plc:oql6ds5vnff4ugar6rruliwd/site.standard.publication/3mn3ohu7oxx5w",
  "tags": [
    "B64G1/244",
    "CUSTOM SENSORS & TECHNOLOGIES INC [US]"
  ],
  "textContent": "Techniques are provided to determine an initial quaternion transform that is used to transform measurements received from accelerometer, rate sensor and inertial reference subsystems from a vehicle coordinate frame to an inertial navigation frame. Methods disclosed determine corrective angular rates to use as a feedback signal to rotate the quaternion transform to counter errors that result when transforming a gravity vector and an inertial reference vector (e.g., a magnetic North reference vector) that are being measured by the accelerometer and an inertial reference subsystems, respectively. The initial quaternion determination is performed during a time period when the only substantial acceleration on the vehicle is due to gravity. The initial quaternion can be used for processing various guidance, navigation and control functions.",
  "title": "Method and system for initial quaternion and attitude estimation"
}