Method and apparatus for tagging digital photographs with geographic location data

Abstract

A method and apparatus for tagging digital photographs with geographic location data is described. In one example, a digital camera includes an imaging unit, a radio frequency/intermediate frequency (RF/IF) front end, and a memory. The imaging unit is configured to generate digital photographs. The RF/IF front end is configured to receive satellite positioning system signals and generate digital samples therefrom. The memory is configured to store a set of digital samples generated by the RF/IF front end with each digital photograph generated by the imaging unit. The digital samples produced by the RF/IF front end may be intermediate frequency samples and may include both in-phase samples and quandrature samples. Notably, the memory stores digital samples of GPS signals, rather than location data. The digital GPS samples may be processed by an off-line processing unit, such as a computer, to produce location data.

1 . A digital camera, comprising:
 an imaging unit for generating digital photographs;   a front end for receiving satellite positioning system signals and generating digital samples therefrom; and   a memory for storing a set of digital samples generated by said front end with each digital photograph generated by said imaging unit.   
     
     
         2 . The digital camera of  claim 1 , wherein each set of digital samples stored in said memory comprises in-phase samples and quadrature samples. 
     
     
         3 . The digital camera of  claim 1 , further comprising:
 a control unit for instructing said imaging unit to capture a digital photograph and for instructing said front end to capture a set of digital samples.   
     
     
         4 . The digital camera of  claim 4 , further comprising:
 a clock for tracking time-of-day;   wherein a time-of-day value generated by said clock is stored with said set of digital samples in said memory.   
     
     
         5 . The digital camera of  claim 1 , wherein said front end comprises:
 an antenna;   a tuner, coupled to said antenna, for translating said satellite positioning system signals to an intermediate frequency; and   an analog-to-digital converter for digitizing said translated satellite positioning system signals to produce said digital samples.   
     
     
         6 . A system for organizing digital photographs, comprising:
 a digital camera, comprising:
 an imaging unit for generating digital photographs; 
 a front end for receiving satellite positioning system signals and generating digital samples therefrom; 
 a memory for storing a set of digital samples generated by said front end with each digital photograph generated by said imaging unit; and 
 a data port configured to communicate with said memory; and 
   a computer, coupled to said data port, for retrieving at least one digital photograph and corresponding set of digital samples from said memory and for processing each set of digital samples retrieved to produce location data.   
     
     
         7 . The system of  claim 6 , wherein said computer is configured to correlate each set of digital samples retrieved from said memory with a pseudorandom reference code to produce pseudorange data. 
     
     
         8 . The system of  claim 7 , wherein said computer is configured to adjust one or more correlation parameters in response to environment data associated with said at least one digital photograph. 
     
     
         9 . The system of  claim 7 , wherein said computer includes a communication port configured for communication with a network, and wherein said computer is configured to receive satellite trajectory data from said network. 
     
     
         10 . The system of  claim 9 , wherein said computer is further configured to compute position data in response to said pseudorange data and said satellite trajectory data. 
     
     
         11 . The system of  claim 10 , wherein said computer is configured to compute said position data using a mathematical model relating said pseudorange data and said satellite trajectory data to updates of position and time variables. 
     
     
         12 . A method, comprising:
 generating one or more digital photographs at a digital camera;   generating one or more sets of digital samples from a plurality of satellite positioning system signals at said digital camera; and   respectively storing said one or more sets of digital samples with said one or more digital photographs in a memory.   
     
     
         13 . The method of  claim 12 , wherein each of said one or more sets of digital samples comprises in-phase samples and quadrature samples. 
     
     
         14 . The method of  claim 12 , further comprising:
 storing a time-of-day value with each of said one or more sets of digital samples.   
     
     
         15 . The method of  claim 12 , wherein said step of generating said one or more sets of digital samples comprises:
 translating said satellite positioning system signals to an intermediate frequency; and   digitizing said translated satellite positioning system signals.   
     
     
         16 . The method of  claim 12 , further comprising:
 retrieving said one or more digital photographs and said one or more sets of digital samples from said memory; and   correlating each of said one or more sets of digital samples with a pseudorandom reference code to produce pseudorange data.   
     
     
         17 . The method of  claim 16 , further comprising:
 adjusting one or more correlation parameters in response to environment data associated with one or more digital photographs.   
     
     
         18 . The method of  claim 16 , further comprising:
 receiving satellite trajectory data from a network; and   computing position data in response to said pseudorange data and said satellite trajectory data.   
     
     
         19 . The method of  claim 18 , wherein said step of computing position comprises:
 relating said pseudorange data and said satellite trajectory data to updates of position and time variables using a mathematical model.   
     
     
         20 . A digital camera, comprising:
 an imaging unit for generating one or more digital photographs;   means for generating one or more sets of digital samples from a plurality of satellite positioning system signals at said digital camera; and   means for respectively storing said one or more sets of digital samples with said one or more digital photographs in a memory.