Patent ID: 7623961
Filing Date: 2009-11-24
Classification: E21B,G01C

Abstract:
1. A method for determining a track of a geographical trajectory which has a predetermined start location and a predetermined end location, said method comprising the steps of: a) moving a data collecting device from the start location to the end location, and while the device is being moved, sample wise collecting physical measurement data related to the movement of the device by a set of onboard sensors of the device, the sensors being synchronised to a common clock signal for said sample wise collection of physical measurement data, wherein the onboard sensors comprise a combination of sensors from whose measurement data a heading profile, a pitch profile and a roll profile are obtained and an odometer measuring a distance travelled with respect to the start location and from whose measurement data a distance profile is obtained, b) determining said heading profile, said pitch profile, said distance profile and said roll profile based on the collected measurement data, c) determining said track based on said heading profile, said pitch profile, said distance profile and said roll profile, characterised in that all said physical measurement data are stored during the movement of the device from the start location to the end location and that, after retrieval of the stored measurement data and before determining said profiles, the method further comprises the steps of: d) determining at least first, respectively second trajectory parameters based on synchronously collected measurement data of a first, respectively second sensor of said set, said synchronously collected measurement data forming part of said stored measurement data, the first sensor measuring a different physical quantity from the second sensor and the first and second trajectory parameters being deduced to relate to a single physical quantity, and mapping said first trajectory parameters on said second trajectory parameters, e) determining an error compensation for said measurement data of said first and said second sensors based on said mapping, f) correcting said measurement data of said first and second sensors by means of said error compensation.