Abstract: A method of determining orientation parameters of a rigid body, including: associating at least two multi-axis accelerometers with the rigid body, wherein the body has a base end, a distal end, and a line of symmetry between the base end and the distal end. The two first multi-axis accelerometers are disposed at a first point along the line of symmetry between the base end and the distal end. Each first multi-axis accelerometer is disposed at equal distances from the line of symmetry. The line of symmetry and both first multi-axis accelerometers lie in a first plane. The method further includes: associating a gyroscope with the body at the first point, equally between both first multi-axis accelerometers; gathering measured data from the two first multi-axis accelerometers and the gyroscope; and applying analysis free of calculus to determine a first inclination angle, of the body from a stable orientation.