1. A GNSS receiver system for receiving signals from GNSS satellites, including at least one SBAS satellite, which receiver system includes:
a receiver including a nonvolatile memory adapted for storing a table of bias corrections for at least one GNSS satellite;
each bias correction including at least one of a group delay correction component and an inter-signal bias correction component; and
an ionosphere-free pseudo range being SBAS-corrected using data broadcast in the SBAS signal as well as data in the bias correction table according to the formula:
R
\u2062
–
(
T
SV
–
\u2062
\u03c4
GD
)
\u2062
–
ISC
L
\u2062
\u2062
1
CA
+
T
SV
GPS
–
\u03c4
GD
GPS
+
T
SV
–
T
SV
GPS
+
ISC
L
\u2062
\u2062
1
CA
–
(
\u03c4
GD
–
\u03c4
GD
GPS
)
=
R
wherein:
the GPS broadcast clock model=TSVGPS;
the broadcast group-delay=\u03c4GDGPS;
the superscript \u201cGPS\u201d indicates that TSVGPS and \u03c4GDGPS are estimates provided by
the GPS Control Segment rather than the true values;
the GPS navigation message, which is modulated on the GPS transmitted signals, contains coefficients of a time-based polynomial fitting TSVGPS;
the navigation message contains a single word providing the group-delay, \u03c4GDGPS;
each satellite sends its respective, satellite-specific values for the above quantities; and
the SBAS clock correction, TSBAS, can be broken down into its individual constituents as follows:
T
SBAS
=
T
SV
–
T
SV
GPS
+
ISC
L
\u2062
\u2062
1
CA
–
(
\u03c4
GD
–
\u03c4
GD
GPS
)
P
iono
\u2062
_
\u2062
free
\u2062
_
\u2062
corrected
CA
=
K
1
\u2062
C
1
–
K
2
\u2062
P
2
+
T
SV
GPS
+
T
SBAS
+
B
ISC_TGD
B
ISC
\u2062
\u2062
_
\u2062
\u2062
TGD
=
K
2
\u2062
ISC
L
\u2062
\u2062
1
CA
+
(
\u03c4
GD
–
\u03c4
GD
GPS
)
;
and
P
iono
\u2062
\u2062
_
\u2062
\u2062
free
\u2062
\u2062
_
\u2062
\u2062
corrected
CA
=
R
.
2. The GNSS receiver system of claim 1, which includes: a Kalman filter adapted for estimating the troposphere as its state.
3. The system of claim 1, which includes:
said GNSS receiver comprising a dual frequency receiver using one of:
L2(P) and L1(P); and
L2(P) and L1(CA).
4. The system of claim 1, which includes means for calibrating the biases using either:
a Kalman filter or a least squares method to: estimate and remove the effects of un-modeled troposphere errors and clock errors; and to effectively time-average the data.
5. The method of claim 1, which includes means for providing a separate BTOTAL value for each of multiple GNSS satellites.
6. A GNSS receiver system for receiving pseudo range signals from GNSS satellites, including at least one SBAS satellite, which receiver system includes:
a receiver including a nonvolatile memory adapted for storing a table of bias corrections for at least one GNSS satellite;
a microprocessor controller connected to said GNSS receiver;
each bias correction including at least one of a group delay correction component and an inter-signal bias correction component;
the pseudo range signals being bias-corrected using data broadcast in the SBAS signal as well as data in the bias correction table; and
the pseudo range being SBAS-corrected using a GNSS broadcast clock model and a broadcast group delay, each satellite sending respective satellite-specific correction values and the biases being calibrated using a Kalman filter or a least squares method to estimate and remove the effects of un-modeled troposphere errors and clock errors and to effectively time-average the data.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A rotary cathode assembly comprising:
a rotary cathode;
a vacuum chamber surrounding at least a portion of said cathode, said vacuum chamber defined by a chamber housing connected and sealed relative to said cathode; a power supply which supplies a current to the cathode; and
a power connection between said power supply and said cathode, said power connection being connected with said cathode at a point within said vacuum chamber.
2. The cathode assembly of claim 1 wherein the current source is a fluctuating current source.
3. The cathode assembly of claim 2 wherein said fluctuating current source is chosen from one or more of the group comprising an AC current source, a bipolar DC current source, and a pulsed DC current source.
4. The cathode assembly of claim 3 wherein said power connection further comprises one or more electrical contact assemblies between said power connection and said cathode.
5. The cathode assembly of claim 4 wherein said electrical contact assemblies further comprise electrical brushes constructed of a carbon or graphite based material with molybdenum disulfide as an additive.
6. The cathode assembly of claim 4 further comprising a main support housing operably attached to the chamber, the main support housing being hollow and surrounding a length of a drive shaft, the drive shaft rotatably supported by the main support housing and connected to said cathode.
7. The cathode assembly of claim 6 wherein said electrical contact assembly is an electrical contact further comprising:
at least one electrical brush disposed in electrical contact with a portion of the rotary cathode.
8. The cathode assembly of claim 7 wherein said at least one electrical brush is made from a carbon or graphite based material with one or more of molybdenum disulfide, CdI2, PbI2, CdCl2, HgI2, BaF2 and dichalcogenides, diselenides and ditellurides of the metals of molybdenum, tungsten, niobium and tantalum.
9. The cathode assembly of claim 8 wherein the electrical brush is made from a carbon or graphite based material with molybdenum disulfide as an additive.
10. The cathode assembly of claim 9 wherein the molybdenum disulfidee is present as an additive in the amount of about 1% to 10% of the carbon or graphite based material.
11. The cathode assembly of claim 10 further comprising a vacuum sealed electrical port disposed on the vacuum chamber, the conductive wire operably connected at a first end to the power supply and operably connected at a second end to the electrical contact, the conductive wire passing through the chamber housing via the vacuum sealed electrical port, whereby the current flows from the power supply, through the conductive wire, and into the electrical contact.
12. The cathode assembly of claim 11 wherein said vacuum seal is a ferro-fluidic seal.
13. A sputter assembly comprising:
a sputter chamber;
one or more rotary sputter cathodes with at least a portion of each of said cathodes positioned within said sputter chamber and a portion of said cathode disposed inside of a housing;
a vacuum seal operably positioned between said cathode and said housing; and
means for supplying a current to the rotary sputter cathode inside of the sputter chamber, thereby avoiding inductive heating of the vacuum seal.
14. The cathode assembly of claim 13 wherein the current source is chose from one or more of the group comprising an oscillating current source, a high power current source, and a fluctuating current source.
15. The cathode assembly of claim 13 wherein said electrical contact assembly is an electrical contact further comprising:
an electrical brush housing operably connected to the main housing and in electrical contact with the same;
and at least one electrical brush disposed in electrical contact on the interior of the housing, the electrical brush in electrical contact with the rotary cathode.
16. The cathode assembly of claim 15 wherein said electrical brush is made from a carbon or graphite based material with an additive to facilitate wear in substantially vacuum conditions.
17. The cathode assembly of claim 15 wherein said electrical brush is made from a carbon or graphite based material with an additive to facilitate current carrying capacity in substantially vacuum conditions.
18. A sputtering cathode assembly comprising:
a rotary cathode;
a vacuum chamber surrounding at least a portion of said cathode, said vacuum chamber defined by a chamber housing connected and sealed relative to said cathode;
a drive shaft connected to said cathode;
a main support housing surrounding a portion of said drive shaft; and
a power supply which supplies a current to the cathode, the current flowing from the power supply, through the main support housing and to the cathode.
19. The cathode assembly of claim 17 wherein said electrical contact assembly is an electrical contact further comprise:
an electrical brush housing operably connected to the main housing and in electrical cooperation with the same;
and at least one electrical brush disposed in electrical contact on the interior of the housing, the electrical brush in electrical contact with the rotary cathode.
20. The cathode assembly of claim 18 wherein said electrical brush is made from a material sufficient to facilitate wear in a substantially vacuum environment.
21. The cathode assembly of claim 19 wherein the alternating current source is chosen from one or more of the group comprising an AC current source, a bipolar DC current source, and a pulsed DC current source.