2. The method of claim 1 , wherein each of the radio scenes detected at the portable electronic device at the respective predetermined reference time comprises a plurality of key-value pairs, each associated with the respective predetermined reference time the radio scene was detected at, wherein the method further comprises: accessing a plurality of key-value pairs, each comprising a respective key, corresponding to a unique transmitter identifier, and a value associated with a signal strength from the respective transmitter received at the portable electronic device at one of the plurality of respective predetermined reference times; and calculating each vector element based on a summation of a plurality of terms, each term calculated from a respective key-value pair by: generating a seed based on (i) the key of the respective key-value pair, (ii) an element identifier associated with the vector element being calculated and (iii) a reference time identifier of the respective predetermined reference time associated with the respective key-value pair.
2. The method of claim 1 , wherein each of the radio scenes detected at the portable electronic device at the respective predetermined reference time comprises a plurality of key-value pairs, each associated with the respective predetermined reference time the radio scene was detected at, wherein the method further comprises: accessing a plurality of key-value pairs, each comprising a respective key, corresponding to a unique transmitter identifier, and a value associated with a signal strength from the respective transmitter received at the portable electronic device at one of the plurality of respective predetermined reference times; and calculating each vector element based on a summation of a plurality of terms, each term calculated from a respective key-value pair by: generating a seed based on (i) the key of the respective key-value pair, (ii) an element identifier associated with the vector element being calculated and (iii) a reference time identifier of the respective predetermined reference time associated with the respective key-value pair. 3. The method of claim 2 , wherein at least one of the keys of the plurality of key-value pairs is associated with one or more synonymous unique identifiers of transmitters located in close proximity to each other, wherein when the key of the respective key-value pair is associated with one or more synonymous unique identifiers, the term in the summation calculated by further adding one or more sub-terms, each calculated from a respective synonymous unique identifier of the one or more synonymous unique identifiers associated with the key of the respective key-value pair by: generating a synonym seed based on (i) the respective synonymous unique identifier (ii) the element identifier associated with the vector element being calculated and (iii) the reference time identifier of the respective predetermined reference time associated with the respective key-value pair; generating a synonym pseudo-random number from the generated synonym seed; and multiplying the synonym pseudo-random number by the value of the respective key-value pair.