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Multi-tone DGPS beacon transmitter and receiver

  • US 5,745,075 A
  • Filed: 06/05/1996
  • Issued: 04/28/1998
  • Est. Priority Date: 06/05/1996
  • Status: Expired due to Term
First Claim
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1. A method for obviating destructive interference between a groundwave and a skywave of a signal, comprising steps of:

  • transmitting a first signal having a first carrier frequency propagating from a transmitter as a first signal groundwave and a first signal skywave;

    transmitting a second signal having a second carrier frequency having a frequency offset from said first carrier frequency, said second carrier frequency propagating from said transmitter as a second signal groundwave and a second signal skywave; and

    using an ionospheric height for calculating said frequency offset for staggering first distances where destructive interference of said first signal groundwave and said first signal skywave occur from second distances where destructive interference between said second signal groundwave and said second signal skywave occur.

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