EP0667518A2 — Profiling of selected atmospheric characteristics…

Claim 1

Independent Claim 93 words

For use in a passive remote sensing device having antenna means for receiving atmospheric microwave emissions containing frequencies of interest, an apparatus for providing a profile of a selected atmospheric characteristic comprising: frequency synthesizing means for providing a plurality of selected frequency outputs; and downconverting means for receiving said plurality of selected frequency outputs from said frequency synthesizing means and said emissions from said antenna means and, responsive thereto, providing output signals indicative of microwave energy emitted by the atmosphere at said frequencies of interest and representing said profile of said atmospheric characteristic.

Claim 2

Dependent Claim 93 words

For use in a passive remote sensing device having antenna means for receiving atmospheric microwave emissions containing frequencies of interest, an apparatus for providing a profile of a selected atmospheric characteristic comprising: frequency synthesizing means for providing a plurality of selected frequency outputs; and downconverting means for receiving said plurality of selected frequency outputs from said frequency synthesizing means and said emissions from said antenna means and, responsive thereto, providing output signals indicative of microwave energy emitted by the atmosphere at said frequencies of interest and representing said profile of said atmospheric characteristic.

Claim 3

Dependent Claim 54 words

The apparatus of claim 1 wherein said received frequencies of interest are a broad atmospheric oxygen line assemblage in a waveband between about 50 and 60 GHz, and wherein said frequency synthesizing means is tunable across said waveband to thereby provide said output signals from said downconverting means representing a profile of atmospheric temperature.

Claim 4

Dependent Claim 27 words

The apparatus of claim 2 wherein said plurality of selected frequency outputs are any selected ones of about 16 frequency intervals between about 50 and 60 GHz.

Claim 5

Dependent Claim 54 words

The apparatus of claim 1 or claim 2 wherein said received frequencies of interest are a pressure broadened water vapor line in a selected waveband, and wherein said frequency synthesizing means is tunable across said waveband to thereby provide said output signals from said downconverting means representing an altitude profile of atmospheric water vapor.

Claim 6

Dependent Claim 77 words

The apparatus of claim 4 wherein said pressure broadened water vapor line waveband is in the range of about 16 to 28 GHz, and wherein said received frequencies of interest also include a frequency in a waveband in the range of 30 to 36 GHz, said apparatus further comprising means for resolving said emissions in said 30 to 36 GHz range at said downconverting means to provide an output signal indicative of liquid content of the atmosphere.

Claim 7

Dependent Claim 46 words

The apparatus of any of claim 1, claim 2 or claim 4 wherein said frequency synthesizing means includes a crystal-referenced, highly stable tunable oscillator connected with said downconverting means and frequency control means connected with said tunable oscillator for controlling selection of said plurality of frequencies.

Claim 8

Dependent Claim 40 words

The apparatus of claim 6 wherein said downconverting means includes mixing means for receiving said emissions and said selected frequency outputs and providing said output signals that selectively represent atmospheric microwave power emitted at different frequency components of said profile.

Claim 9

Independent Claim 38 words

The apparatus of any of claims 1 through 7 further comprising a controller for operating the device, storing said output signals, and controlling tuning of said frequency synthesizing means to each of an ensemble of user defined frequencies.

Claim 10

Independent Claim 37 words

The apparatus of any of claims 1 through 8 further comprising means for characterizing gain and offset of the passive remote sensing device at each observation to enhance accuracy of said output signals and thus said profile.

Claim 11

Dependent Claim 28 words

The apparatus of claim 1 wherein the atmospheric characteristic is atmospheric temperature and wherein said frequency synthesizing means is tunable across selected intervals between 40 and 80 GHz.

Claim 12

Dependent Claim 46 words

The apparatus of claim 1 wherein the atmospheric characteristic is water vapor content, and wherein said frequency synthesizing means is tunable across selected intervals over about 6 GHz in a band responsive to said frequencies of interest corresponding to a selected pressure broadened water vapor line.

Claim 13

Dependent Claim 43 words

The apparatus of claim 1 wherein the atmospheric characteristic is cloud liquid water content, and wherein said frequency synthesizing means is tunable across separate wavebands at the low and high frequency sides of either of a selected water vapor or oxygen resonance line.

Claim 14

Dependent Claim 51 words

The apparatus of claim 12 wherein said selected water vapor or oxygen resonance line is an oxygen resonance at about 60 GHz, said frequency synthesizing means being tunable between about 40 and 60 GHz at said low frequency side and between about 60 and 80 GHz at said high frequency side.

Claim 15

Independent Claim 40 words

The apparatus of any of claims 1 through 13 further comprising calibration means for calibrating the passive remote sensing device, said calibration means including a cryogenic target and mounting means for removably positioning said cryogenic target above the antenna means.

Claim 16

Independent Claim 80 words

A method for profiling a selected atmospheric characteristic comprising the steps of: admitting atmospheric microwave emissions containing frequencies of interest into a volume; synthesizing a plurality of signals responsive to said atmospheric microwave emissions at said frequencies of interest and admitting said signals into said volume to downconvert said emissions from said frequencies of interest; and generating output signals indicative of microwave energy emitted by the atmosphere at said frequencies of interest to provide a profile of said atmospheric characteristic.

Claim 17

Independent Claim 80 words

A method for profiling a selected atmospheric characteristic comprising the steps of: admitting atmospheric microwave emissions containing frequencies of interest into a volume; synthesizing a plurality of signals responsive to said atmospheric microwave emissions at said frequencies of interest and admitting said signals into said volume to downconvert said emissions from said frequencies of interest; and generating output signals indicative of microwave energy emitted by the atmosphere at said frequencies of interest to provide a profile of said atmospheric characteristic.

Claim 18

Dependent Claim 58 words

The method of claim 15 wherein said atmospheric characteristic is atmospheric temperature, wherein said frequencies of interest are a broad band atmospheric oxygen line assemblage in a waveband between about 40 and 80 GHz, and wherein the step of synthesizing a plurality of signals includes tuning across said waveband to downconvert said emissions at said frequencies of interest.

Claim 19

Dependent Claim 54 words

The method of claim 15 wherein said atmospheric characteristic is atmospheric water vapor content, wherein said frequencies of interest are a pressure broadened water vapor line in a selected waveband, and wherein the step of synthesizing a plurality of signals includes tuning across said waveband to downconvert said emissions at said frequencies of interest.

Claim 20

Dependent Claim 23 words

The method of claim 17 wherein said pressure broadened water vapor line waveband is in the range of about 16 to 28 GHz.

Claim 21

Dependent Claim 56 words

The method of claim 17 wherein said atmospheric characteristic is also atmospheric liquid content, and wherein said frequencies of interest also include a frequency in the range of about 30 to 36 GHz, said method further comprising the step of providing a signal to downconvert said emissions at said 30 to 36 GHz frequency of interest.

Claim 22

Independent Claim 50 words

The method of any of claims 15 through 19 further comprising the steps of repeatedly admitting emissions, synthesizing responsive signals and generating output signals to provide ongoing observations, and characterizing error producing environmental conditions at each said observation to reduce error in said output signals and thus in said profile.

Claim 23

Dependent Claim 34 words

The method of any of claims claim 15 through 19 wherein the step of synthesizing signals includes tuning a crystal referenced, highly stable oscillator to each frequency of a user selected ensemble of frequencies.

Claim 24

Dependent Claim 68 words

The method of claim 15 wherein the atmospheric characteristic is cloud liquid water content, and wherein said frequencies of interest are assemblages in separate wavebands at the low and high frequency sides of either of a selected water vapor or oxygen resonance line, and wherein the step of synthesizing a plurality of signals includes simultaneously tuning across said wavebands to downconvert said emissions at said frequencies of interest.

Claim 25

Dependent Claim 44 words

The radiometer of claim 22 wherein said selected water vapor or oxygen resonance line is an oxygen resonance at 60 GHz, said low frequency side being between about 40 and 60 GHz and said high frequency side being between about 60 and 80 GHz.

Profiling of selected atmospheric characteristics utilizing passive microwave remote sensing

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