Navigation system
First Claim
1. A navigation system comprising at least one pulse radar means for transmitting interrogating radar pulses of determinable repetition period and including a display means for making a display of echo signals which may include reflected signals, and at least one transponder means for receiving radar pulses and for transmitting in response to said pulses high frequency pulse modulated response signals, the transponder means including delay means and means associated with delay means for transmitting, on receiving an interrogating signal from the pulse radar means, response signals with a delay such that response signals from the said transponder means are displayed on the display with displacement relative to the position that the response signals would be displayed without said delay, said radar means including means for generating a scan on said display means and delay means for delaying the start of the scan by the same value as the delay of the response signal whereby the echo signals which are received from objects within a predetermined range of said pulse radar means are received before the start of the scan and thus are not shown whereas response signals from the transponder are displayed in the display, both said delay means providing respective delays of equal value and of such substantial fraction of the repetition period as to eliminate all but the strongest echo signals received after the start of the scan.
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Accused Products
Abstract
A navigation system including at least one pulse radar and a number of transponders which when receiving radar pulses transmit high frequency pulse modulated signals. When receiving an interrogating signal from the pulse radar the transponder transmits a response signal with a delay. The delay is selected in such a manner that the response signal arrives at the pulse radar within a time space lying between the moment when all signal echos, lying within a definite range, have been received and the moment when the next radar pulse begins. The display scan in the radar is delayed by the same value as the response signal. In this way the response signal competes with considerably weaker echo signals than in the case of a non delayed response.
13 Citations
9 Claims
- 1. A navigation system comprising at least one pulse radar means for transmitting interrogating radar pulses of determinable repetition period and including a display means for making a display of echo signals which may include reflected signals, and at least one transponder means for receiving radar pulses and for transmitting in response to said pulses high frequency pulse modulated response signals, the transponder means including delay means and means associated with delay means for transmitting, on receiving an interrogating signal from the pulse radar means, response signals with a delay such that response signals from the said transponder means are displayed on the display with displacement relative to the position that the response signals would be displayed without said delay, said radar means including means for generating a scan on said display means and delay means for delaying the start of the scan by the same value as the delay of the response signal whereby the echo signals which are received from objects within a predetermined range of said pulse radar means are received before the start of the scan and thus are not shown whereas response signals from the transponder are displayed in the display, both said delay means providing respective delays of equal value and of such substantial fraction of the repetition period as to eliminate all but the strongest echo signals received after the start of the scan.
Specification
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- Resources
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Current AssigneeTelefonaktiebolaget LM Ericsson
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Original AssigneeTelefonaktiebolaget LM Ericsson
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InventorsGustavsson, Per-Olof G., Andersson, Bengt L., Morwing, Bo A.
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Primary Examiner(s)Tubbesing, T. H.
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Assistant Examiner(s)Barron, Jr., Gilberto
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Application NumberUS06/514,827Time in Patent Office1,272 DaysField of Search343/6.5 R, 343/6.8 RUS Class Current342/46CPC Class CodesG01S 13/76 wherein pulse-type signals ...
