Re: [SpectrumLabUsers] LR Lightning Radar DSP and GPS improvement.
- Am 20.07.2013 15:22, schrieb Gerry G.:Hi Wolf,I see all your saying. I think we must be talking about different things on the 500 Usec. I was only referring to this sentence in your manual where its talking about using the GPS without NMEA.Quote: " Method B is only possible if the PC's system time is accurately set (difference between the PC's system time and the GPS second way below 500 milliseconds) !" I think that just means the digital clock readout stuff. Not the true clock phase.
Yes possibly. I don't see how the LRA hardware can actually remove the sampling errors from a soundcard. Its job is to minimize errors in the PC's system time (at least I think that's what it is supposed to do).We are using Frank Kooimans program which uses no GPS data at all or sync except from the cpu clock and sound card clock. What he calls Real time and non real time (ie sound card). He then phases the stations together if they are not too far apart drift and frequency wise.
I take it from your discussion that this LRA effort that is using the parallel port input for GPS then cant work? Due to all the things you mentioned in the last discussion. Or maybe again we're talking about two different things?
SL could do, with an awful lot of work, the same job (synchronizing the PC's system time) but I still don't see the point how this could be used to provide a highly accurate timestamp for a block of samples *FROM THE SOUNDCARD*.Here is a link to the LRA sync screen where it shows 0 Usec GPS PPS Vs. 'processor' clock error. If I understand it right this means the station cpu clock and GPS are now in sync with 0 difference according to that screen anyway.. This sync method is using the port method that doesn't work, so between the LRA sync and what your telling me I'm becoming a little confused to say the least. It would seem that either SL could do the same as LRA is doing on the port, or LRA is not doing what it shows?
Ok, time to go outside and do something else now.
Have a nice weekend,