C# Code for NS-HP RTK GPS base station working. Allows for a client on the local network to connect to a REST endpoint on a PI 2 and receive RTCM 3 messages for corrections. So far I have only been able to achieve a FloatRTK fix. However the accuracy is still much improved over conventional GPS. I used a NS-HP-10 with a 5Hz update rate. The message age maxed out around 500ms.
I am pretty happy to achieve the accuracy I do with about $125 worth of GPS equipment, a Raspberry PI 2 for the base station.