A method for generating an optimum measurement subset from a set of input global navigation satellite system (GNSS) measurements, wherein the number of input GNSS measurements in the set of input GNSS measurements is a first integer, wherein the number of input GNSS measurements in the optimum measurement subset is a specified second integer, and wherein the specified second integer is less than the first integer, the method comprising the steps of: receiving the set of input GNSS measurements; generating a design matrix, wherein the design matrix is based at least in part on partial derivatives of the set of input GNSS measurements with respect to at least one target parameter; generating a weight matrix, wherein the weight matrix is based at least in part on measurement errors associated with the set of input GNSS measurements; calculating values of a set of coefficients, wherein each specific coefficient in the set of coefficients corresponds to a specific input GNSS measurement in the set of input GNSS measurements, and wherein the step of calculating values of a set of coefficients comprises the steps of, for each specific input GNSS measurement in the set of input GNSS measurements: calculating, based at least in part on the design matrix and based at least in part on the weight matrix, a change in value of the at least one target parameter resulting from a change in value of the specific input GNSS measurement; calculating, based at least in part on the design matrix and based at least in part on the weight matrix, a change in value of a sum of squared residuals resulting from a change in value of the specific input GNSS measurement; and calculating the value of a specific coefficient as the ratio of the change in value of the at least one target parameter resulting from the change in value of the specific input GNSS measurement to the change in value of the sum of squared residuals resulting from the change in value of the specific input GNSS measurement; and selecting the optimum measurement subset based at least in part on the values of the set of coefficients. receiving the set of input GNSS measurements; generating a design matrix, wherein the design matrix is based at least in part on partial derivatives of the set of input GNSS measurements with respect to at least one target parameter; generating a weight matrix, wherein the weight matrix is based at least in part on measurement errors associated with the set of input GNSS measurements; calculating values of a set of coefficients, wherein each specific coefficient in the set of coefficients corresponds to a specific input GNSS measurement in the set of input GNSS measurements, and wherein the step of calculating values of a set of coefficients comprises the steps of, for each specific input GNSS measurement in the set of input GNSS measurements: calculating, based at least in part on the design matrix and based at least in part on the weight matrix, a change in value of the at least one target parameter resulting from a change in value of the specific input GNSS measurement; calculating, based at least in part on the design matrix and based at least in part on the weight matrix, a change in value of a sum of squared residuals resulting from a change in value of the specific input GNSS measurement; and calculating the value of a specific coefficient as the ratio of the change in value of the at least one target parameter resulting from the change in value of the specific input GNSS measurement to the change in value of the sum of squared residuals resulting from the change in value of the specific input GNSS measurement; and calculating, based at least in part on the design matrix and based at least in part on the weight matrix, a change in value of the at least one target parameter resulting from a change in value of the specific input GNSS measurement; calculating, based at least in part on the design matrix and based at least in part on the weight matrix, a change in value of a sum of squared residuals resulting from a change in value of the specific input GNSS measurement; and calculating the value of a specific coefficient as the ratio of the change in value of the at least one target parameter resulting from the change in value of the specific input GNSS measurement to the change in value of the sum of squared residuals resulting from the change in value of the specific input GNSS measurement; and selecting the optimum measurement subset based at least in part on the values of the set of coefficients.