L1 and L2 can post correct ionosphere noise, as they travel differently there. They cannot post correct troposphere differences because they travel the same the

L1 and L2 can post correct ionosphere noise, as they travel differently there. They cannot post correct troposphere differences because they travel the same there. Without RTK, which measures the time varying local errors, you cannot undo that error with current GNS systems. It's precisely this reason RTK was developed.