Phase based measurement corrections
AssigneeQinetiq Limited
InventorCharles Robert Offer
Life of this patent
Estimating the term…
Abstract
A method for providing correction values for phase based measurements. Where averaging techniques are employed for exploiting redundancy in multiple measurements, by constraining the phase ambiguity in a correction value to be an integer multiple of the carrier wavelength, carrier phase based measurements can be used.
Claims16
A method for deriving a correction value An for a phase-based satellite navigation measurement for a satellite n, from a common set of a plurality of base station reference receivers M and a plurality of satellites N, wherein the phase ambiguity an in the correction value is constrained to be an integer multiple of the carrier wavelength λ.
A method according to any preceding claim, wherein said phase correction value is determined as:
- A
- nf
- =
- 1
- M
-
- ∑
- m
-
- [
- (
- A
- nmf
- ′
- -
- δ
-
-
- a
- nmf
- p
- 0
-
- q
- 0
- +
- c
- nf
- )
- -
- 1
- N
-
- ∑
- n
- ′
-
- (
- A
- n
- ′
-
- mf
- ′
- -
- δ
-
-
- a
- n
- ′
-
- mf
- p
- 0
-
- q
- 0
- +
- c
- n
- ′
-
- f
- )
- ]
- Where:
- Anf is the phase correction value for satellite n at frequency f
- M is the total number of base station reference receivers in the common set
- N is the total number of satellites in the common set
- Anmf′ is the component correction value for receiver m for satellite n at frequency f
- δanmfp0q0 is the double differenced reference receiver ambiguity for receiver m for satellite n at frequency f relative to a chosen satellite receiver pair p0q0
- cnf is an integer multiple of the carrier wavelength
A method according to any preceding claim, wherein said correction value is used to determine an estimate of position of an object relative to an average of the positions of the base station receivers, and wherein said estimate is subsequently transformed to be relative to a selected base station reference point.
A method of deriving a satellite navigation estimate for an object relative to a plurality of base station reference receivers, the method comprising:
- deriving a first estimate of the position of said object relative to an average position of said reference receivers, and
- deriving a second estimate of position of said object relative to a selected base station reference point, based on said first estimate.
A method for deriving a correction value An for a phase-based measurement of separation of a transmission source n, from a common set of a plurality of reference stations M, where the reference stations each make phase based measurements of distance from a plurality of transmission sources N, wherein the phase ambiguity an in the correction value is constrained to be an integer multiple of the carrier wavelength λ.
Dependencies are inferred from the claim text.