Abstract: Using an inertial master box mounted on a carrier for measuring its movements with respect to a geographic frame of reference of fixed directions along three axes Xg, Yg, Zg, a measuring method provides for continuously measuring an orientation of a frame of reference Xm, Ym, Zm tied to the inertial master box. Positioning is provided by applying a sequence of cycles of eight inversions of the inertial master box while keeping the axis Ym in a direction parallel to the axis Yg. A first motor causes a gimbal to pivot on a first axle secured to the carrier, while a second motor causes the inertial master box to pivot about a second perpendicular axle secured to the gimbal. A processor calculates three attitude angles by running a first inertial navigation program of the strapdown type and controls the first and second motors by running a second program.

Abstract: Using an inertial master box (3) mounted on a carrier for measuring its movements with respect to a geographic frame of reference of fixed directions along three axes Xg, Yg, Zg, the method comprises measuring actions which consist in constantly measuring an orientation of a frame of reference tied to the inertial master box Xm, Ym, Zm by using the inertial master box (3) in the geographic frame of reference, positioning actions which consist in applying a sequence of cycles of eight turnings-over of the inertial master box (3) each of which keeps the axis Ym in a direction parallel to the axis Yg, a succession of two turnings-over about the axis Xm being preceded and followed by a turning-over about the axis Zm, a succession of two turnings-over about the axis Zm being preceded and followed by a turning-over about the axis Xm.