Scatterometer with adaptable spatial resolution
First Claim
1. An apparatus for sensing and processing global positioning system (GPS) signals reflected from an ocean surface, said apparatus comprising:
- a receiving means for receiving said GPS signals;
a generator means for generating pseudo-random noise codes;
a pair of parallel delay means for delaying said pseudo-random noise codes;
a pair of parallel code correlator means for generating correlated signals by correlating said GPS signals with said delayed pseudo-random noise codes; and
a signal correlator means for correlating said correlated signals from said code correlator means to generate a power signal averaged over a time period;
wherein said delay means and said code correlator means are variable for decreasing a footprint of the ocean surface region from which said GPS signals are received.
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Accused Products
Abstract
A global positioning system (GPS) ocean scatterometer with an adaptable spatial resolution for sensing and processing GPS signals reflected from an ocean surface for wind measurements in a wide range of altitudes and wind velocities. To increase wind sensitivity at low altitudes, the GPS ocean scatterometer employs a sub-chip GPS receiver which includes, inter alia, a signal correlator and a pair of code correlators for generating a sub-chip footprint to boost system resolution. To increase wind sensitivity at high altitudes, the GPS ocean scatterometer employs a multi-chip GPS receiver which includes, inter alia, a wide-band oscillator and a multi-chip generator for generating a multi-chip footprint to boost scattered energy.
62 Citations
14 Claims
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1. An apparatus for sensing and processing global positioning system (GPS) signals reflected from an ocean surface, said apparatus comprising:
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a receiving means for receiving said GPS signals; a generator means for generating pseudo-random noise codes; a pair of parallel delay means for delaying said pseudo-random noise codes; a pair of parallel code correlator means for generating correlated signals by correlating said GPS signals with said delayed pseudo-random noise codes; and a signal correlator means for correlating said correlated signals from said code correlator means to generate a power signal averaged over a time period; wherein said delay means and said code correlator means are variable for decreasing a footprint of the ocean surface region from which said GPS signals are received. - View Dependent Claims (2)
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3. A method for sensing and processing global positioning system (GPS) signals reflected from an ocean surface region, said method comprising the steps of:
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receiving said GPS signals; generating pseudo-random noise codes; delaying said pseudo-random noise codes in parallel; forming correlated signals by correlating said GPS signals in parallel with said delayed pseudo-random noise codes; and outputting a power signal averaged over a time period by correlating said correlated signals from said code correlator means; wherein said delaying of said pseudo-random noise codes and forming of correlated signals are variable for decreasing a footprint of the ocean surface region from which said GPS signals are received. - View Dependent Claims (4)
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5. An apparatus for sensing and processing global positioning system (GPS) signals reflected from an ocean surface region, said apparatus comprising:
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a receiving means for receiving said GPS signals; a generator means for generating a pseudo-random noise code; a first delay means for delaying said pseudo-random noise code by a first time period; a second delay means for delaying said pseudo-random noise code by a second time period; a first code correlator means for generating a first correlated signal by correlating said GPS signals with said pseudo-random noise code delayed by said first delay means; a second code correlator means for generating a second correlated signal by correlating said pseudo-random noise code delayed by said second delay means; and a signal correlator means for receiving said first and second correlated signals from said first and second code correlator means, wherein said first two correlated signals are averaged over a third time period by said signal correlator means; wherein said first and second delay means and said first and second code correlator means are variable for decreasing a footprint of the ocean surface region from which said GPS signals are received. - View Dependent Claims (6)
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7. A method for sensing and processing global positioning system (GPS) signals reflected from an ocean surface region, said method comprising the steps of:
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receiving said GPS signals; generating a pseudo-random noise code; delaying said pseudo-random noise code by a second time period which is different from said first time period; generating a first correlated signal by correlating said GPS signals with said pseudo-random noise code delayed by said first delay means; generating a second correlated signal by correlating said pseudo-random noise code delayed by said second delay means; and receiving said first and second correlated signals from said first and second code correlator means, wherein said first two correlated signals are averaged over a third time period by said signal correlator means; wherein said delaying of said-random noise code by the first and second time periods and the generating of the first and second correlated signals are variable for decreasing a footprint of the ocean surface region from which said GPS signals are received. - View Dependent Claims (8)
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9. An apparatus for sensing and processing a global position system signal reflected from a terrestrial sphere, said apparatus comprising:
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a receiving means for receiving said GPS signal; an oscillator means for generating an oscillating signal of a wide bandwidth; a mixer means for multiplying said oscillating signal with said GPS signal; a generator means for generating a time-shifted pseudo-random noise code; a delay means for delaying said time-shifted pseudo-random noise code by a predetermined time period; a code correlator means for generating a correlated signal by correlating said integrated signal with said time-shifted pseudo-random noise code by said delay means; and a power averaging means for averaging said correlated signal from said code correlator means over a predetermined time period; wherein said generator means comprises a multi-chip generator, and said delay means and said code correlator means are variable for increasing a footprint of an area from which said apparatus receives said GPS signal. - View Dependent Claims (10, 11)
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12. A method for sensing and processing a global positioning signal reflected from a terrestrial sphere, said method comprising the steps of:
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receiving said GPS signal; forming an oscillating signal of a wide bandwidth; multiplying said oscillating signal with said GPS signal to form an integrated signal; generating a time-shifted pseudo-random noise code by a multi-chip generator; delaying said time-shifted pseudo-random noise code by a predetermined time period; correlating said integrated signal with said time-shifted pseudo-random noise code delayed by said delay means to yield a correlated signal; and averaging said correlated signal from said code correlator means over a predetermined time period; wherein the predetermined time period of said delaying step and the correlating step of said time-shifted pseudo-random noise code are variable to increase a footprint of an area from which said receiving step receives said GPS signal. - View Dependent Claims (13, 14)
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Specification