Use correct delta time calculation for simulations to residual error script
Added option for linear extrapolation in roll_module (default is to not extrapolate, and populate out-of-range values with 0s as before)
Use crosstrack values from file in roll_module when interpolating, to properly account for the nadir gap
Added option to specify a seed when calling tropo_module
Added option to residual error script to generate tropo distribution for a range of records that may be larger than the pixel cloud extent (such that consistent errors can be added across multiple pixel clouds)
Updates for adding residual errors