Radar acquisition system

• US 5,589,833 A
• Filed: 04/21/1995
• Issued: 12/31/1996
• Est. Priority Date: 04/21/1995
• Status: Expired due to Term

• Current Assignee: University Corporation For Atmospheric Research
• Original Assignee: University Corporation For Atmospheric Research
• Inventors: Randall, Mitchell A., Loew, Eric
• Primary Examiner(s): Pihulic, Daniel T.
• Application Number:
  US08/426,030
• Time in Patent Office: 620 Days
• Field of Search: 342/194, 342/195, 342/196, 342/26, 342/59
• US Class Current: 342/195
• CPC Class Codes: G01S 7/03 Details of HF subsystems specially adapted therefor, e.g. common to transmitter and receiver
• CPC Class Codes: G01S 7/288 Coherent receivers
• CPC Class Codes: G01S 7/292 Extracting wanted echo-signals
• CPC Class Codes: G01S 7/295 Means for transforming co-ordinates or for evaluating data, e.g. using computers

Abstract

The personal computer based integrated radar acquisition (PIRAQ) system integrates a programmable timing generator, a digital Intermediate Frequency (IF) processor, and a digital signal processor on a standardized personal computer "add-on" electronic circuit module that accepts standard IF input and produces standard radar display outputs. The digital intermediate frequency processor includes an IF pre-processor, a programmable digital matched filter, and a wide dynamic range digital baseband converter. Implementing the PIRAQ system in digital components on a single electronic circuit module for use in a personal computer provides and efficient, low-cost, portable, and programmable high-performance radar acquisition system hardware base from which radar signals can be digitally processed.

Claims

1. A radar acquisition system comprising:

an electronic circuit module operatively connected to a host processor, wherein said electronic circuit module contains a plurality of signal processing components thereon;

means for receiving a radio wave;

means for converting said radio wave into an analog intermediate frequency signal; and

means for producing in-phase and quadrature signal components from said analog intermediate frequency signal by way of at least one of said plurality of signal processing components independent of any radar signal processing component external to said electronic circuit module and said host processor.

2. A system according to claim 1 wherein said means for receiving said radio wave comprises:

a high frequency radar antenna.

3. A system according to claim 1 wherein said processor is a personal computer.

4. A system according to claim 1 wherein said means for converting comprises:

means for amplifying said radio wave;

means for converting said radio wave into an analog intermediate frequency signal; and

means for filtering said analog intermediate frequency signal with a wideband anti-alias filter to remove unnecessary frequencies from said analog intermediate frequency signal.

5. A system according to claim 1 wherein said means for producing in-phase and quadrature signal components comprises:

means for mixing said analog intermediate frequency signal with an oscillator signal to produce a plurality of limited bandwidth center frequency signals; and

means for filtering said plurality of limited bandwidth center frequency signals to reject low frequency noise, frequency harmonics, and low frequency side-bands prior to digitizing said plurality of limited bandwidth center frequency signals.

6. A system according to claim 5 further comprising:

means for converting said plurality of limited bandwidth center frequency signals to a digital intermediate frequency signal;

means for mixing said digital intermediate frequency signal with a sine oscillator input to reduce said digital intermediate frequency signal into a series of sums and differences therebetween in a first output signal;

means for mixing said digital intermediate frequency signal with a cosine oscillator input to reduce said digital intermediate frequency signal into a series of sums and differences therebetween in a second output signal in parallel with said first output signal; and

means for filtering said first output signal and said second output signal to reject low frequency signal interference produced by said converting means thereby producing high-frequency baseband in-phase and quadrature signal components.

7. A system according to claim 6 further comprising:

means for accumulating said series of sums and differences for a plurality of range gates within a signal pulse width for said first output signal and said second output signal wherein said accumulating means is programmable with respect to said plurality of range gates, said signal pulse width, and a control frequency; and

means for digitally filtering out sums from said first output signal and said second output signal to produce raw in-phase and quadrature signal components.

8. A system according to claim 1 further comprising:

means for generating a plurality of timing signals from a single timing generator for use by said plurality of signal processing components.

9. A system according to claim 1 further comprising:

means for networking a plurality of said electronic circuit modules wherein said input frequency for each of said electronic circuit modules is user programmable and of a mode type selected from the group consisting of;

synchronous, and asynchronous;

means for interfacing with each of said plurality of said electronic circuit modules for debugging purposes; and

means for reporting electronic circuit module status to a user by way of predefined and user programmable visual indicators.

10. A system according to claim 1 further comprising:

means for interconnecting said plurality of signal processing components on said electronic circuit module in at least one manner selected from the group consisting of;

surface mounted, printed circuit, and integrated circuit, wherein said plurality of signal processing components are interconnected therebetween absent any board external cabling.

11. A system according to claim 1 further comprising:

means for digitally discriminating frequency drift resulting from an incoherent transmission received by way of said receiving means; and

means for compensating for said frequency drift by altering said transmission frequency toward a predetermined ideal frequency.

12. A radar acquisition system comprising:

an electronic circuit module having a plurality of radar signal processing components thereon;

a host processor operatively connected to said electronic circuit module;

means for inputting an analog intermediate frequency radar signal to said electronic circuit module; and

means for generating in-phase and quadrature signal components from said analog intermediate frequency radar signal by way of at least one of said plurality of radar signal processing components on said electronic circuit module independent of any radar signal processing component external to said electronic circuit module and said host processor.

13. A method for processing a radio wave in a radar acquisition system, said method comprising the steps of:

operatively connecting an electronic circuit module to a processor, wherein said electronic circuit module contains a plurality of signal processing components thereon;

converting said radio wave into an analog intermediate frequency signal; and

producing in-phase and quadrature signal components from said analog intermediate frequency signal by way of at least one of said plurality of signal processing components independent of any radar signal processing component external to said electronic circuit module and said host processor.

14. A method according to claim 13 wherein said step of converting comprises:

amplifying said radio wave;

converting said radio wave into an analog intermediate frequency signal; and

filtering said analog intermediate frequency signal with a wideband anti-alias filter to remove unnecessary frequencies from said analog intermediate frequency signal.

15. A method according to claim 13 wherein said step of producing in-phase and quadrature signal components comprises:

mixing said analog intermediate frequency signal with an oscillator signal to produce a plurality of limited bandwidth center frequency signals; and

filtering said plurality of limited bandwidth center frequency signals to reject low frequency noise, frequency harmonics, and low frequency side-bands prior to digitizing said plurality of limited bandwidth center frequency signals.

16. A method according to claim 15 further comprising:

converting said plurality of limited bandwidth center frequency signals to a digital intermediate frequency signal;

mixing said digital intermediate frequency signal with a sine oscillator input to reduce said digital intermediate frequency signal into a series of sums and differences therebetween in a first output signal;

mixing said digital intermediate frequency signal with a cosine oscillator input to reduce said digital intermediate frequency signal into a series of sums and differences therebetween in a second output signal in parallel with said first output signal; and

filtering said first output signal and said second output signal to reject low frequency signal interference produced by said step of converting thereby producing high-frequency baseband in-phase and quadrature signal components.

17. A method according to claim 16 further comprising:

accumulating said series of sums and differences for a plurality of range gates within a signal pulse width for said first output signal and said second output signal wherein said accumulating means is programmable with respect to said plurality of range gates, said signal pulse width, and a control frequency; and

digitally filtering out sums from said first output signal and said second output signal to produce raw in-phase and quadrature signal components.

18. A method according to claim 13 further comprising:

generating a plurality of timing signals from a single timing generator for use by said plurality of signal processing components.

19. A method according to claim 13 further comprising:

networking a plurality of said electronic circuit modules wherein said input frequency for each of said electronic circuit modules is user programmable and of a mode type selected from the group consisting of;

synchronous, and asynchronous;

interfacing with each of said plurality of said electronic circuit modules for debugging purposes; and

reporting electronic circuit module status to a user by way of predefined and user programmable visual indicators.

20. A method according to claim 13 further comprising:

interconnecting said plurality of signal processing components on said electronic circuit module in at least one manner selected from the group consisting of;

surface mounted, printed circuit, and integrated circuit, wherein said plurality of signal processing components are interconnected therebetween absent any board external cabling.

21. A method according to claim 13 further comprising:

digitally discriminating frequency drift resulting from an incoherent transmission received by way of said receiving means; and

compensating for said frequency drift by altering said transmission frequency toward a predetermined ideal frequency.

22. A method for processing radar data in a radar acquisition system, said method comprising:

operatively connecting an electronic circuit module to a host processor, wherein said electronic circuit module contains a plurality of radar signal processing components thereon;

inputting an analog intermediate frequency signal to said electronic circuit module; and

generating in-phase and quadrature signal components from said analog intermediate frequency signal by way of at least one of said plurality of radar signal processing components on said electronic circuit module independent of any radar signal processing component external to said electronic circuit module and said host processor.