Dual Source GPS/DCF77 NTP-Server with AIS and ADS-B receivers
1 Scope
This project is a continuation of my stream of experiments with the NTP protocol and GPS-disciplined clock models. I need to reference the past projects before we go into details:
- NTP-Server with Raspberry Pi and Trimble Resolution SMT
- NTP-Server with Raspberry Pi and Sure Electronics GPS Eval board
These past projects raised the question, how precise a DCF-77 clock would be. And this project here also needs to be seen in the context of an April 1st joke of Rainer DF2NU, who proposed that DCF-77 can be switched off now because the GPS system is there and it is much more precise. So I started to collect ideas to investigate how less precise a DCF-77 disciplined clock model would be compared to the GPS Pulse Per Second.
In addition to the clock question I was thinking of setting up a pair of receivers for the AIS frames broadcasted around Regensburg by the shipd on the danube and I wanted to receove ADS-B frames. Even though slowly navigating ships allow for some frame processing delay, and in case the delay is a couple of seconds, one would still consider such an application a real time application. A jet plane however travels quite distance in a couple of seconds, so a positioning application would need to add some timestamping logic in order to allow for a realistic position information, particularly if received by multiple receivers.
For this reason it makes perfect sense to add a precise clock to a position frame receiver setup.
2 List of components
- The chassis: http://shop.meconet.de/Gehaeuse/Outdoor/Chassis-Outdoor-CA-OTU-RB-433-RB-435-RB-493-RB-800-3-LAN-4-N-Type-large::111356.html - 72 €
- A Raspberry Pi 3: https://www.amazon.de/Raspberry-Pi-3-Model-B/dp/B01CEFWQFA - 35 €
- SanDisk 32GB MicroSD Card: https://www.amazon.de/SanDisk-Android-microSDHC-Speicherkarte-SD-Adapter/dp/B013UDL5RU/ref=sr_1_1 - 10 €
- GUDE Expert Mouse Clock 0107
