公开(公告)号：US06677893B2

公开(公告)日：2004-01-13

申请号：US10276592

申请日：2002-11-19

申请人： Robert M Rideout ,  Paul R Edmonds ,  Simon R Duck ,  David P Haworth ,  Christopher Griffin

发明人： Robert M Rideout ,  Paul R Edmonds ,  Simon R Duck ,  David P Haworth ,  Christopher Griffin

IPC分类号： H04B7185

CPC分类号： G01S5/06 ,  G01S1/026

摘要： A method of locating the source of an unknown signal of varying frequency received by receive antennas (16, 18) via relay satellites (12, 14) involves downconversion of received signals to a first intermediate frequency (IF) and band-limiting the downconverted signals. The band-limited signals are constrained to lie within a prearranged acquisition signal bandwidth by adjustment of local oscillator (LO) downconversion frequency to counteract frequency change in the unknown signal. Downconverted signals are offset in time relative to one another using trial values of differential time offset and their correlation is determined for each trial value to provide actual time offset. Compensation is provided for change in correlation phase angle, which results from signals being downconverted experiencing different LO frequencies during the time interval of the trial offset.

摘要翻译： 定位由接收天线（16,18）经由中继卫星（12,14）接收的变化频率的未知信号源的方法包括将接收到的信号下变频到第一中频（IF）并对下变频信号 。 通过调整本地振荡器（LO）下变频频率以抵消未知信号中的频率变化，带限信号被限制在预定义的采集信号带宽内。 下变频信号相对于彼此使用差分时间偏移的试验值在时间上偏移，并且为每个试验值确定它们的相关性以提供实际的时间偏移。 提供相关相位角变化的补偿，这是由于在试验偏移的时间间隔期间经历不同LO频率的信号被下变频产生的。

公开(公告)号：US06618009B2

公开(公告)日：2003-09-09

申请号：US09955224

申请日：2001-09-19

申请人： Christopher Griffin ,  Paul R. Edmonds ,  Simon R. Duck

发明人： Christopher Griffin ,  Paul R. Edmonds ,  Simon R. Duck

IPC分类号： G01S504

CPC分类号： G01S5/02 ,  G01S1/026 ,  G01S1/045 ,  G01S5/0009 ,  G01S5/06

摘要： A method of determining the location of an unknown source 10 transmitting a signal to satellite relays 14 and 16 comprises receiving replicas of the signal from the relays at receivers 18. The receivers 18 also transmit and receive reference signals via respective relays 14 and 16. All signals are downconverted, digitized and correlated with one another in pairs using a correlation function including a term which compensates for time varying differential frequency offset (DFO). Compensation for time varying differential time offset or time dilation is achieved by replicating or adding to signal samples and applying phase corrections. This procedure enables a correlation maximum and associated measurement results to be obtained despite the effects of relay satellite motion which mitigate against this. Results are used in a prior art geometrical technique to locate the unknown transmitter.