@Ultima Thule my dear friend, Read this carefully. I wrote this since i feel youre looking for Truth.
First there are different approaches for developing LPS. I give you some example in this regard hope it gives you clue that Iran can easily develop own positioning systems.
SLR. This approach uses laser pulses transmitted from Ground systems in order to provide absolute location of the unknown station or the transmitter. Usually the unknown Factor in this approach is the absolute location of Ground stations /transmitters. You can orient your stations with provided data through this approach hence making them a base for positioning purposes. It can provide you with the following factors: absolute positioning of stations, determination of earth gravity field, making a Reference, orienting erth motions, orbital calculations etc.
VLBI. In this approach we use quasars for positioning purposes. It requires Giant antennas which Iran possesses already. I could explain this approach step by step if you wish.
One could use DORIS method which Works Based on Doppler-shift of radio signals transmitted from Ground stations. We can use this Double signal system without needing authorization from French side. What im trying to say is that developing an LPS in Iran would be more than easy for us. GPS is generally designed to remove the barriers of these absolute systems and making Kinematic positioning available with high accuracy. GPS sats Transfer 2 kind of signals in L1 and L2 bands onwhich codes and navigational massages are moduled. Ground stations receive these signals. Through interpolation of received signals and having the location of sats which requires Ground Based radars, you can determine the location of Ground stations and hence orienting your radars. The primary GPS systems enjoyed 24 sats in 3 orbital planes with an angle of 63 degrees, this was changed to 18 sats due to financial reasons and that 3 on every orbital plane having 1 extra accessory sat increasing the number of sats to 4 per orbital plane with an angle of 55 degrees. In USA, US military uses PPS while using P-code for navigation that are immune to SA and AS Effects. DOD of USA is using this approach. Civilian users are allowed only to use SPS approach which restricts using of using P-code for positioning and instead allows them to use C/A codes which are affected by AS and SA lowering the accuracy of positioning. However SA was removed a couple of decades ago. The SA or selective availability is a method of denying unauthorized real-time use of full GPS position and velocity accuracy, as provided by the PPS.
How could they, Americans, Lower the accuracy of GPS positioning system?
They don't need to send or replace satellites of GPS with New ones and then send them into orbit and if they do so then they are bunch of retards.
Dye the fact that they have developed every code of GPS, P C/A Y X etc, they can build forged signals and then send them to Ground recievers to Lower their accuracy. They have every info about the forged signals so they can define other methods to Decode and hence remove wrong signals or deliberate errors in the system.
During war times US adversaries can do the same and try to jam the GPS signals, the Solution would be تو widen the band that the signals are being sent through. Its anti jamming approach of US military. This very approach exposes the codes and other forged signals and also makes it possible for US adversaries to easily Decode GPS signals hence being able to use PPS.