Patent ID: 7557748

Claim:
A method for determining at least one of motion and location parameters of a railroad locomotive, with the locomotive oriented with either end thereof in the lead in the direction of travel of the locomotive, said method comprising the steps of: providing at least two satellite signal receivers on the locomotive at spaced locations along the length of the locomotive; determining a vector distance {right arrow over (d)} between the two satellite signal receivers using an integer ambiguity, wherein an initial integer ambiguity is resolved by consulting a database that provides an initial heading and track grade as a function of latitude and longitude; determining a set of phase differences between satellite reference signals received by satellite receivers; and determining an accurate heading, accurate heading rate, attitude, and attitude rate of the locomotive during normal locomotive transit operation using only the set of phase differences between the satellite reference signals and the vector distance {right arrow over (d)} the method further comprising the step of determining {right arrow over (d)} as {right arrow over (d)}=(H T H) −1 H T {right arrow over (y)}, where: H = [ LOS x 1 LOS y 1 LOS z 1 LOS x 2 LOS y 2 LOS z 2 ... ... ... LOS x n LOS y n LOS z n ] ; y -> = [ Δϕ 1 - λ ⁡ ( N 1 1 - N 2 1 ) - c ⁡ ( dt 1 - dt 2 ) Δϕ 2 - λ ⁡ ( N 1 2 - N 2 2 ) - c ⁡ ( dt 1 - dt 2 ) ⋮ Δϕ n - λ ⁡ ( N 1 n - N 2 n ) - c ⁡ ( dt 1 - dt 2 ) ] ; and d -> = [ d x d y d z ] , where ø represents a fractional phase part, where n represents a number of satellites in the GPS system.