Systems and methods for a high-precision time of arrival ultra-wideband positioning system

Abstract

Systems and methods for a high-precision time of arrival ultra-wideband positioning system are provided. In one embodiment, a method for generating precision localizer messages for an ultra-wideband time-of-arrival positioning system is provided. The method comprises receiving a signal from an atomically accurate reference, generating a timing signal based on the atomically accurate reference signal, correcting a system time based on the timing signal when an error is detected, and transmitting an ultra-wideband signal having a localization message based on the system time.

1 . A method for generating precision localizer messages for an ultra-wideband time-of-arrival positioning system, the method comprising: 
 receiving a signal from an atomically accurate reference;    generating a timing signal based on the atomically accurate reference signal;    correcting a system time based on the timing signal; and    transmitting an ultra-wideband signal having a localization message based on the system time.    
   
   
       2 . The method of  claim 1 , wherein receiving a signal from an atomically accurate reference comprises at least one of: 
 receiving a signal from a global positioning system satellite; and    receiving a signal from a Galileo system satellite.    
   
   
       3 . The method of  claim 1 , wherein generating a timing signal based on the atomically accurate reference signal further comprises generating a timing signal that includes a periodic timing pulse and a time message that indicates the time the pulse occurs.  
   
   
       4 . The method of  claim 3 , wherein the periodic timing pulse is an integral part of the timing message.  
   
   
       5 . The method of  claim 1 , wherein correcting a system time based on the timing signal further comprises: 
 correcting the system time based on a difference between the system time and a time embedded within the timing signal.    
   
   
       6 . The method of  claim 1 , wherein adjusting a system time based on the timing signal further comprises: 
 initiating an interrupt when the timing signal is received;    generating a time tag record that is time stamped with the system time corresponding to when the interrupt occurred; and    removing accumulated error from the system time by adjusting the system time based on the difference between a time provided by the timing signal and the time stamp of the time tag record.    
   
   
       7 . The method of  claim 1 , wherein transmitting an ultra-wideband signal having a localization message further comprises: 
 transmitting a localization message including location information and time information that indicates the time when the localization message was transmitted.    
   
   
       8 . A positioning system, the system comprising: 
 one or more reference units each adapted to receive a time signal from at least one atomically accurate reference and maintain a system time based on the time signal, wherein each reference unit is further adapted to transmit a localizer message via an ultra-wideband signal, the localizer message including location information for the reference unit and time information indicating the system time when the localizer message was transmitted; and    a mobile receiver unit adapted to calculate a distance to a first reference unit of the one or more reference units based on a first localizer message received from the first reference unit.    
   
   
       9 . The system of  claim 8 , each of the one the one or more reference units further comprising: 
 an ultra-wideband localizer adapted to transmit the localizer message via an ultra-wideband signal;    a clock coupled to the ultra-wideband localizer, wherein the ultra-wideband localizer is adapted to maintain the system time based on the clock;    a receiver coupled to the ultra-wideband localizer and adapted to receive the time signals from the at least one atomically accurate reference and generate a periodic timing signal;    wherein the ultra-wideband localizer is further adapted to adjust the system time based on the periodic timing signal.    
   
   
       10 . The system of  claim 8 , each of the one or more reference units further comprising: 
 at least one antenna coupled to the one or more reference units and adapted to receive the time signals from the at least one atomically accurate reference.    
   
   
       11 . The system of  claim 8 , wherein each one the one or more reference units are further adapted to initiate an interrupt when the timing signal is received, generate a time tag record that is time stamped with the system time corresponding to when the interrupt occurred, and remove accumulated error from the system time by adjusting the system time based on the difference between a time provided by the timing signal and the time stamp of the time tag record.  
   
   
       12 . The system of  claim 8 , wherein the receiver is further adapted to receive one or both of a signal from a global positioning system satellite and a signal from a Galileo system satellite.  
   
   
       13 . The system of  claim 8 , wherein the mobile unit is further adapted to calculate a location based on at least three distances to at least three reference units based on localizer messages received from the at least three reference units.  
   
   
       14 . A reference unit for a positioning system, the reference unit comprising: 
 means for receiving a time signal from an atomically accurate reference;    means for generating a periodic timing signal based on the atomically accurate reference signal, the means for generating responsive to the means for receiving;    means for maintaining a system time;    means for transmitting an ultra-wideband signal having a localization message, wherein the localization message includes location information for the reference unit and time information indicating the system time when the localization message is transmitted; and    means for correcting the system time based on a difference between the system time and a time embedded within the timing signal, the means for adjusting responsive to the means for generating a periodic timing signal and the means for maintaining a system time.    
   
   
       15 . The reference unit of  claim 14 , wherein the means for generating a periodic timing signal is adapted to generate a timing signal that includes a periodic timing pulse and a time message that indicates the time the pulse occurs.  
   
   
       16 . The reference unit of  claim 14 , wherein the means for correcting the system time further comprises: 
 means for initiating an interrupt when the timing signal is received;    means for generating a time tag record that is time stamped with the system time corresponding to when the interrupt occurred; and    means for removing accumulated error from the system time by adjusting the system time based on the difference between a time provided by the timing signal and the time stamp of the time tag record.    
   
   
       17 . A computer-readable medium having computer-executable program instructions for a method for generating precision localizer messages for an ultra-wideband time-of-arrival positioning system, the method comprising: 
 receiving a signal from an atomically accurate reference;    generating a periodic timing signal based on the global atomically accurate reference signal, wherein the timing signal includes a time message that indicates the time the periodic timing is generated;    correcting a system time based on a difference between the system time and the time message included within the timing signal; and    transmitting an ultra-wideband signal having a localization message based on the system time.    
   
   
       18 . The computer-readable medium of  claim 17 , wherein the periodic timing pulse is an integral part of the timing message.  
   
   
       19 . The computer-readable medium of  claim 17 , the method further comprising: 
 initiating an interrupt when the timing signal is received;    generating a time tag record that is time stamped with the system time corresponding to when the interrupt occurred; and    removing accumulated error from the system time by adjusting the system time based on a difference between a time provided by the timing signal and the time stamp of the time tag record.    
   
   
       20 . The computer-readable medium of  claim 17 , the method further comprising: 
 transmitting an ultra-wideband signal having a localization message including location information and time information that indicates the time when the localization message is transmitted.    
   
   
       21 . A reference unit for a positioning system, the reference unit comprising: 
 a receiver adapted to receive a time signal from at least one atomically accurate reference and generate a periodic timing signal;    an ultra-wideband localizer adapted to transmit a localizer message via an ultra-wideband signal, the localizer message including location information for the reference unit and time information indicating the system time when the localizer message was transmitted;    a clock coupled to the ultra-wideband localizer, wherein the ultra-wideband localizer is adapted to maintain the system time based on the clock;    wherein the ultra-wideband localizer coupled to the receiver and is further adapted to correct the system time based on the periodic timing signal.    
   
   
       22 . The reference unit of  claim 21  further comprising: 
 at least one antenna coupled to the receiver and adapted to receive the time signals from the at least one atomically accurate reference.    
   
   
       23 . The reference unit of  claim 21 , wherein the ultra-wideband localizer is further adapted to initiate an interrupt when the timing signal is received, generate a time tag record that is time stamped with the system time corresponding to when the interrupt occurred, and remove accumulated error from the system time by adjusting the system time based on the difference between a time provided by the timing signal and the time stamp of the time tag record.  
   
   
       24 . The reference unit of  claim 21 , wherein the receiver is further adapted to receive one or both of a signal from a global positioning system satellite and a signal from a Galileo system satellite.