System and method for correcting global navigation satellite system carrier phase measurements in receivers having controlled reception pattern antennas
First Claim
1. An apparatus for calibrating a global navigation satellite system (GNSS) receiver for receiver or antenna hardware induced direct path signal errors in carrier phase measurements of GNSS transmitter direct path signals when tracking the GNSS transmitter direct path signals, the apparatus comprising:
- a controlled reception pattern antenna (CRPA) comprising a plurality of receiving elements and configured to sense a plurality of direct path signals from a GNSS transmitter;
a digital sampler circuit configured to convert the plurality of sensed GNSS direct path signals to a plurality of sampled digital signals; and
a digital processor configured to;
access stored direct path phase calibration correction data for at least some combinations of the plurality of receiving elements and a plurality of transmitter orientations with respect to the CRPA;
generate direct path beam steering control data using a transmitter orientation with respect to the CRPA;
combine the accessed direct path phase calibration correction data specific to the transmitter orientation with respect to the CRPA and each of the plurality of receiving elements together with the direct path beam steering control data to generate corrected direct path beam steering control data;
generate a composite corrected direct path digital signal by combining the sampled digital signals and the corrected direct path beam steering control data; and
convert the composite corrected direct path digital signal into a corrected direct path GNSS carrier phase measurement.
1 Assignment
0 Petitions
Accused Products
Abstract
This invention discloses a method for enhancing a Global Navigation Satellite System (GNSS), such as Global Positioning System (GPS), location calculation by supplying carrier phase corrections within a GNSS receiver used with a multiple element Controlled Reception Pattern Antenna (CRPA) receiver. GNSS carrier phase measurements should be compensated for receiver hardware and directionally dependent antenna errors to obtain desired accuracies for high precision GNSS positioning applications. One technique successfully employed in Fixed Reception Pattern Antenna (FRPA) GPS sensors applies a simple directionally dependent set of correction factors to the measurement outputs. For the complex case of a GNSS receiver employing a CRPA and dynamic beam steering, however, the multiplicity of combinations of antenna element outputs makes the FRPA compensation technique impractical. Compensation of carrier phase measurements is a problem not addressed in previous GPS CRPA beam steering sensors.
49 Citations
14 Claims
-
1. An apparatus for calibrating a global navigation satellite system (GNSS) receiver for receiver or antenna hardware induced direct path signal errors in carrier phase measurements of GNSS transmitter direct path signals when tracking the GNSS transmitter direct path signals, the apparatus comprising:
-
a controlled reception pattern antenna (CRPA) comprising a plurality of receiving elements and configured to sense a plurality of direct path signals from a GNSS transmitter; a digital sampler circuit configured to convert the plurality of sensed GNSS direct path signals to a plurality of sampled digital signals; and a digital processor configured to; access stored direct path phase calibration correction data for at least some combinations of the plurality of receiving elements and a plurality of transmitter orientations with respect to the CRPA; generate direct path beam steering control data using a transmitter orientation with respect to the CRPA; combine the accessed direct path phase calibration correction data specific to the transmitter orientation with respect to the CRPA and each of the plurality of receiving elements together with the direct path beam steering control data to generate corrected direct path beam steering control data; generate a composite corrected direct path digital signal by combining the sampled digital signals and the corrected direct path beam steering control data; and convert the composite corrected direct path digital signal into a corrected direct path GNSS carrier phase measurement. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. A method for calibrating a global navigation satellite system (GNSS) receiver for receiver or antenna hardware induced direct path signal errors in carrier phase measurements of GNSS transmitter direct path signals when tracking the GNSS transmitter direct path signals, the method comprising:
-
sensing a plurality of direct path signals from a GNSS transmitter with a controlled reception pattern antenna (CRPA) comprising a plurality of receiving elements; digitally sampling the sensed GNSS direct path signals to produce a plurality of sampled digital signals; accessing stored direct path phase calibration correction data for at least some combinations of the plurality of receiving elements and a plurality of transmitter orientations with respect to the CRPA; generating direct path beam steering control data using a transmitter orientation with respect to the CRPA; combining the accessed direct path phase calibration correction data specific to the transmitter orientation with respect to the CRPA and each of the plurality of receiving elements together with the direct path beam steering control data to generate corrected direct path beam steering control data; generating a composite corrected direct path digital signal by combining the sampled digital signals and the corrected direct path beam steering control data; converting the composite corrected direct path digital signal into a corrected direct path GNSS carrier phase measurement. - View Dependent Claims (11, 12, 13, 14)
-
Specification