A positioning system comprising: - several inertial measurement units (U 1, U i, U N), each inertial measurement unit (U i) comprising at least one inertial sensor, accelerometer or gyrometer, configured to provide an inertial signal (S i) representative of an acceleration or an angular speed of rotation of the measurement unit (U i), - at least one common sensor (C 1, Cp), configured to provide a measurement ( mes n) of a positioning parameter (y) of the system, said measurement ( mes n) being affected by a measurement noise, - for each inertial measurement unit (U i), an individual navigation filter (F i k) configured to: a) determine an estimate ( ŷ k,i) of said positioning parameter ( y), on the basis of the inertial signal (S i) provided by said inertial measurement unit, and to b) determine a corrected estimate y ^ cor k, i of said positioning parameter by adding to said estimate ( ŷ k,i) previously determined at step a) a corrective term equal to a correction gain (K n) multiplied by a difference between, on the one hand, said measurement ( mes n) of the positioning parameter (y) of the system, and, on the other hand, the product of a measurement matrix (H n) multiplied by said estimate of the positioning parameter or multiplied by a sum of said estimate ( ŷ k,i) and of an estimated error x ^ n _ k, i affecting said estimate ( ŷ k,i), the measurement matrix (H n) representing the way said measurement ( mes n) depends on the positioning parameter (y) of the system, the correction gain (K n) being determined as a function of an augmented variance (V aug) that is higher than the variance of the measurement noise (R n) of the common sensor (C 1, Cp), and - at least one fusion module (F us k) configured to determine a mean estimate y ^ F k, l of said positioning parameter (y) of the system by calculating a mean of a given number (k) of said corrected estimates y ^ cor k, i of the positioning parameter, said number (k) being higher than or equal to two and lower than or equal to the number of inertial measurement units (U 1, U i, U N) that are included in the positioning system, the system being configured so that each individual navigation filter (F i k) executes several times, successively, all the steps a) and b) without taking into account said mean estimate y ^ F k, l determined by the fusion module (F us k). - several inertial measurement units (U 1, U i, U N), each inertial measurement unit (U i) comprising at least one inertial sensor, accelerometer or gyrometer, configured to provide an inertial signal (S i) representative of an acceleration or an angular speed of rotation of the measurement unit (U i), - at least one common sensor (C 1, Cp), configured to provide a measurement ( mes n) of a positioning parameter (y) of the system, said measurement ( mes n) being affected by a measurement noise, - for each inertial measurement unit (U i), an individual navigation filter (F i k) configured to: a) determine an estimate ( ŷ k,i) of said positioning parameter ( y), on the basis of the inertial signal (S i) provided by said inertial measurement unit, and to b) determine a corrected estimate y ^ cor k, i of said positioning parameter by adding to said estimate ( ŷ k,i) previously determined at step a) a corrective term equal to a correction gain (K n) multiplied by a difference between, on the one hand, said measurement ( mes n) of the positioning parameter (y) of the system, and, on the other hand, the product of a measurement matrix (H n) multiplied by said estimate of the positioning parameter or multiplied by a sum of said estimate ( ŷ k,i) and of an estimated error x ^ n _ k, i affecting said estimate ( ŷ k,i), the measurement matrix (H n) representing the way said measurement ( mes n) depends on the positioning parameter (y) of the system, the correction gain (K n) being determined as a function of an augmented variance (V aug) that is higher than the variance of the measurement noise (R n) of the common sensor (C 1, Cp), and a) determine an estimate ( ŷ k,i) of said positioning parameter ( y), on the basis of the inertial signal (S i) provided by said inertial measurement unit, and to b) determine a corrected estimate y ^ cor k, i of said positioning parameter by adding to said estimate ( ŷ k,i) previously determined at step a) a corrective term equal to a correction gain (K n) multiplied by a difference between, on the one hand, said measurement ( mes n) of the positioning parameter (y) of the system, and, on the other hand, the product of a measurement matrix (H n) multiplied by said estimate of the positioning parameter or multiplied by a sum of said estimate ( ŷ k,i) and of an estimated error x ^ n _ k, i affecting said estimate ( ŷ k,i), the measurement matrix (H n) representing the way said measurement ( mes n) depends on the positioning parameter (y) of the system, the correction gain (K n) being determined as a function of an augmented variance (V aug) that is higher than the variance of the measurement noise (R n) of the common sensor (C 1, Cp), and - at least one fusion module (F us k) configured to determine a mean estimate y ^ F k, l of said positioning parameter (y) of the system by calculating a mean of a given number (k) of said corrected estimates y ^ cor k, i of the positioning parameter, said number (k) being higher than or equal to two and lower than or equal to the number of inertial measurement units (U 1, U i, U N) that are included in the positioning system,