Tracking of occluded navigation satellite signals

Patent metadata

Field	Value
Publication number	US-9476990-B2
Application number	US-201414574708-A
Country	US
Kind code	B2
Filing date	Dec 18, 2014
Priority date	Dec 18, 2014
Publication date	Oct 25, 2016
Grant date	Oct 25, 2016

Abstract

A navigation system includes a first navigation module for determining a first position and a second navigation module for determining a second position. The first and the second navigation modules are mechanically connected, such that the first position is dependent on the second position. Also, the first and the second navigation modules are communicatively connected to exchange information including at least one of the first and the second positions. At an instant of time during an operation of the navigation system, the first navigation module receives the second position from the second navigation module and determines the first position based on the second position.

First claim

We claim:

1. A navigation system, comprising:
a first navigation module for determining a first position; and
a second navigation module for determining a second position, wherein the first and the second navigation modules are mechanically connected, such that the first position is dependent on the second position, wherein the first and the second navigation modules are communicatively connected to exchange information including at least one of the first and the second positions, and wherein, at an instant of time during an operation of the navigation system, the first navigation module receives the second position from the second navigation module and determines the first position based on the second position, wherein the first navigation module determines a first velocity and determines the first position based on the first velocity and the second position, and wherein the first navigation module determines a phase of a satellite signal using the first position determined upon receiving the second position, determines a frequency of the satellite signal using the first velocity, and initializes tracking of the satellite signal according to the frequency and the phase of the satellite signal.

2. The navigation system of claim 1 , wherein the first navigation module receives a second velocity from the second navigation module and determines the first velocity using the second velocity.

3. The navigation system of claim 1 , wherein the first navigation module determines the first position using a relative velocity between the first and the second navigation modules.

4. The navigation system of claim 1 , wherein the first navigation module receives the first velocity from a velocity measurement system rigidly connected with the first navigation module.

5. The navigation system of claim 1 , wherein the first navigation module determines the first position using a relative distance between the first and the second navigation modules.

6. The navigation system of claim 5 , wherein the first navigation module and the second navigation module are rigidly connected.

7. The navigation system of claim 5 , wherein the first navigation module adjusts the relative distance using geographic information.

8. The navigation system of claim 5 , wherein the first and the second navigation modules are arranged at different cars of a train and connected by the cars of the train, wherein the first navigation module adjusts the relative distance using information about the connection between the cars, and geographic information.

9. The navigation system of claim 1 , wherein the first navigation module determines the phase {circumflex over (Φ)} of the satellite signal according to

Φ
^

=

[

1
c

⁡

[



x

(
k
)

-

x
u



-

(

b

(
k
)

-

b
^

A

)

]

+

A
1

⁢

f
Dopp

+

A

0
⁢
φ

]

Λ

,

wherein {circumflex over (x)} A is the first position of first navigation module A, x (k) is a position of a satellite k transmitting the satellite signal, c is the speed of light, {circumflex over (b)} A is a clock bias on the first navigation module A, φ is the phase of the satellite signal, A 0 and A 1 are receiver dependent constants, and b (k) is a bias on the clock of the satellite k, brackets with subscript [ ] Λ indicate the modulo operation, and Λ is a spatial length of a pseudorandom code identifying the satellite k being re-acquired,
wherein the first navigation module determines the frequency {circumflex over (f)} of the satellite signal according to

f
^

(
k
)

=

(

v
u

-

v

(
k
)

)

·

1

(
k
)

λ

+

f
0

1

(
k
)

=

Assignees

• Mitsubishi Electric Res Laboratories Inc

Inventors

• Kim Kyeong Jin
• Osechas Okuary
• Kniazev Andrei
• Parsons Kieran
• Sahinoglu Zafer

Classifications

• G01S19/26

  involving a sensor measurement for aiding acquisition or tracking · CPC title

• G01S19/426

  by combining or switching between position solutions or signals derived from different modes of operation in a single system · CPC title

• G01S19/29

  carrier {including Doppler,} related {(G01S19/246 takes precedence)} · CPC title

• G01S19/50

  whereby the position solution is constrained to lie upon a particular curve or surface, e.g. for locomotives on railway tracks · CPC title

• G01S19/25

  involving aiding data received from a cooperating element, e.g. assisted GPS · CPC title