1. A method for estimating calibration for ground based beam forming in a satellite communications network, the method comprising: obtaining a measurement of gain of a first calibration signal retransmitted from one or more satellite elements, the first calibration signal being communicated by a first calibration station located at a first geographic location, the measurement of gain of the first calibration signal including a first measurement of gain for a first element of the one or more satellite elements retransmitting the first calibration signal; accessing a first expected gain for the first element retransmitting the first calibration signal; computing a first weight indicative of a confidence in the first measurement, at least in part, by calculating a gradient of a first geodetic radiation gain pattern of the first element; obtaining a measurement of gain of a second calibration signal retransmitted by one or more satellite elements, the second calibration signal being communicated by a second calibration station located at a second geographic location that is different from the first geographic location, the measurement of gain of the second calibration signal including a second measurement of gain for a second element of the one or more satellite elements retransmitting the second calibration signal; accessing a second expected gain for the one or more satellite elements retransmitting the second calibration signal; computing a second weight indicative of a confidence in the second measurement, at least in part, by calculating a gradient of a first geodetic radiation gain pattern of the second element; generating a cost function using at least the obtained measurement of gain for the one or more satellite elements retransmitting the first calibration signal, the obtained measurement of gain for the one or more satellite elements retransmitting the second calibration signal, the accessed first expected gain for the first element retransmitting the first calibration signal and the accessed second expected gain for the second element retransmitting the second calibration signal, the computed weights indicative of the confidences in the first and second measurements; computing values for one or more unknown variables by reducing the cost function with respect to the one or more unknown variables, the one or more unknown variables including at least a satellite element relative gain or at least a calibration station relative gain; and storing the values.