  In conventional global navigation satellite system (GNSS) receivers, usually
full pseudorange measurements are required to complete a single point position
fix. However, to obtain full pseudorange measurements takes longer time than
for fractional pseudorange measurements. Considering such a fact, in order to
shorten the time to first fix and improve the position accuracy during cold or
warm start of a dual-constellation GNSS receiver, we propose a positioning
algorithm using full and fractional pseudorange measurements from the two
navigational constellations. This method uses four full pseudorange
measurements from one constellation along with fractional ones from either or
both constellations to obtain a potentially rapid position result with an
identical accuracy to that of the conventional positioning method using full
measurements. Tests with simulated and real Global Positioning System (GPS) and
BeiDou Navigation Satellite System (BDS) data demonstrate that the proposed
method can generate correct single point position solutions and the position
error is identical with the result from the conventional approach using the
full pseudorange measurements.
