Good to know that. Actually I also notice that radio astronomy is attracting more and more signla processing researchers to work on it. Some conference, such as ICASSP, envn setup a dedicate session on radio astronomy. There is a radio astronomy called "DOME" are carrying on, which involves computation on massive data and signal processing algorithm.
You have notice the problem that re-tuning will casue lossing synchronization. That's also the problem I considered. Because we always want the rtl-sdr work in the band we are interested, but unfortunatelly in that band there maybe no any pre-known reference signal for us to do synchronization. So a possible solution maybe make a beacon, which can generate ultra-narrow-band or ultra-low-power signal in the target band to help us do the on-line calibration. Any better ideas to avoid this dedicate beacon? On Mon, Dec 30, 2013 at 11:09 PM, Leif Asbrink <[email protected]> wrote: > Hello Jiao, > > > My thought is doing the compensation by software according > > to a common source over the air instead of over the hardware. > > > > Do you think it is doable? > > Yes. This is most certainly possible. The same thing was done long > ago in radio astronomy. Two big telescopes on different continents > made recordings aiming at a coomon direction in the sky. By > evaluating the recordings they could make interferometry. > > http://en.wikipedia.org/wiki/Very-long-baseline_interferometry > > This is a very interesting approach for the future. > With several dongles that have some signals in common it > will be possible to synchronize in software. > > One of the common signals could be a GPS diciplined frequency > standard that the software could use to provide extreme > frequency stability on the processed signals from all the dongles. > > Once syncronization is arranged one could use the multi-channel > antenna for interference suppression and to improve S/N of any > desired signal. > > > And what would be the bottleneck according to your experience? > There is a lot of code that has to be written, but > I do not think there is any bottleneck to worry about > in hardware > > > Any possibility to tune the hardware by software after we > > estimate the synchronization error in frequency and timing? > The entire passband of the dongles will be coherent. > You can tune to any frequency within the passband and also > evaluate several frequencies at the same time. > > In case one wants to change the center frequency one would > loose synchronization and one would have to restart the > synchronization procedure. > > SDR has just begun. Most of the interesting things have > not yet been done:-) > > Regards > > Leif / SM5BSZ > > > >
