Dual Source GPS/DCF77 NTP-Server with AIS and ADS-B receivers: Unterschied zwischen den Versionen

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* MMCX 10cm - 10 €
 
* MMCX 10cm - 10 €
 
* FL Pigtail 25cm - 10 €
 
* FL Pigtail 25cm - 10 €
 +
* AISspotter USB stick: http://busse-yachtshop.de/s/AIS-Empfaenger-im-USB-Stick-Gehaeuse - 99 €
  
 
The prices are partly a bit over the market, roundet up, so that there are no surprises.
 
The prices are partly a bit over the market, roundet up, so that there are no surprises.

Version vom 10. Dezember 2016, 14:06 Uhr

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:

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 prices are partly a bit over the market, roundet up, so that there are no surprises.

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