A method for position estimation comprising: accessing, by executing an instruction with a processor, carrier phase measurements and code measurements obtained for a plurality of satellite signals received by a receiver from a plurality of satellites of a global navigation satellite system; determining, by executing an instruction with the processor, an initial set of floating-point ambiguities based on the carrier phase measurements and the code measurements, the initial set of floating-point ambiguities including an inter-frequency bias; performing, by executing an instruction with the processor, a least squares search process based on the initial set of floating-point ambiguities to determine a selected set of integer ambiguities and a corresponding estimate of the inter-frequency bias for use in at least one of estimating a position of the receiver or determining a satellite correction signal for broadcast, wherein performing of the least squares search process includes performing a modified least-squares ambiguity decorrelation adjustment, LAMBDA, search process adapted to determine the selected set of integer ambiguities and the corresponding estimate of the inter-frequency bias to minimize a first value of a first quadratic formula modeling an error between the initial set of floating-point ambiguities and the selected set of integer ambiguities after removal of the corresponding estimate of the inter-frequency bias from the initial set of floating-point ambiguities, and wherein the first value is based on a difference of a second value of a second quadratic formula and a third value, the second quadratic formula modeling an error between the initial set of floating-point ambiguities and the set of integer ambiguities without removal of the estimate of the inter-frequency bias from the initial set of floating-point ambiguities, and the third value modeling a contribution of the estimate of the inter-frequency bias to the error modeled by the second quadratic formula is estimated based on a difference of an integer ambiguity candidate vector and a corresponding float ambiguity vector, a variance-covariance matrix of the difference and a differential frequency number vector representing the differences between the frequency numbers of a reference satellite and non-reference satellites. accessing, by executing an instruction with a processor, carrier phase measurements and code measurements obtained for a plurality of satellite signals received by a receiver from a plurality of satellites of a global navigation satellite system; determining, by executing an instruction with the processor, an initial set of floating-point ambiguities based on the carrier phase measurements and the code measurements, the initial set of floating-point ambiguities including an inter-frequency bias; performing, by executing an instruction with the processor, a least squares search process based on the initial set of floating-point ambiguities to determine a selected set of integer ambiguities and a corresponding estimate of the inter-frequency bias for use in at least one of estimating a position of the receiver or determining a satellite correction signal for broadcast, wherein performing of the least squares search process includes performing a modified least-squares ambiguity decorrelation adjustment, LAMBDA, search process adapted to determine the selected set of integer ambiguities and the corresponding estimate of the inter-frequency bias to minimize a first value of a first quadratic formula modeling an error between the initial set of floating-point ambiguities and the selected set of integer ambiguities after removal of the corresponding estimate of the inter-frequency bias from the initial set of floating-point ambiguities, and wherein the first value is based on a difference of a second value of a second quadratic formula and a third value, the second quadratic formula modeling an error between the initial set of floating-point ambiguities and the set of integer ambiguities without removal of the estimate of the inter-frequency bias from the initial set of floating-point ambiguities, and the third value modeling a contribution of the estimate of the inter-frequency bias to the error modeled by the second quadratic formula is estimated based on a difference of an integer ambiguity candidate vector and a corresponding float ambiguity vector, a variance-covariance matrix of the difference and a differential frequency number vector representing the differences between the frequency numbers of a reference satellite and non-reference satellites.