Described herein are systems and techniques for mitigating the impact of attenuated satellite signals received at mobile devices. A mobile device receives multiple signals from a single satellite on different carrier frequencies. The mobile device calculates two pseudorange measurements, each pseudorange measurement from a different signal of the multiple signals. The mobile device calculates the difference between the two pseudorange measurements, and if the difference exceeds a first threshold and the first pseudorange measurement is larger than the second pseudorange measurement, the mobile device marks the first pseudorange measurement as impaired. If the difference exceeds a second threshold and the second pseudorange measurement is larger than the first pseudorange measurement, the second pseudorange measurement is marked as impaired. The impaired measurements may be weighted or excluded from use in calculating a position of the mobile device or in another pseudorange measurement based calculation.