Glen, as the GSoC guy I have a couple of comments. But first of all, I'm glad there's interest from more radio astronomers in GNU Radio -- as Marcus points out, there's already a couple of RAs using GNU Radio, and you'll find a bunch of nice experiments out there.
On 02/07/2017 01:20 PM, Glen I Langston wrote: > Hello GNU radio folks, > > A few radio astronomer friends have had a very active interest in GNU > Radio, but > I’m aware of relatively few Radio Astronomy oriented contributions to > GNU radio. > > This email is a request to start a discussion on > some requirements of Radio Astronomy and the software support they would > need. > > The main GNU Radio enhancement items on my short list are: > 1) Averaging of spectra for long periods (minutes to hours), while > capturing every spectrum. > 2) Writing average and transient spectra based on internal and external > events. > a) Maybe this already exists, but a spectrum message is needed so that > averaging can be separated from writing. > b) Transient event detection with spectrum (or time sequence) passed to > a writing thread. > c) When sudden increases of signal are noted, time sequences would be > written. (When auto-detected). I would guess that most of these are already possible in GR; they might be put into a more accessible form. > 3) Keeping tracking of information associated with the observing setup. > There are large numbers of ancillary data > values needed to calibrate and map spectral observations (geographic > location, precise time, horn/antenna azimuth, elevation > gains, device types used for the observations, flags to indicate > calibration spectra etc). We've just started work on a file format we call "SigMF", which we plan to integrate into GR, and would solve these issues. > I’ve greatly appreciated the GNU Radio software and excellent quality of > the GRC and all the code I’ve seen. > I’ve extensively modified the ‘FFT sink' to optimize for averaging and > added a write component inside that code. > Writing inside averaging is probably a mistake, as writing suspends data > collection for a short time. I need to learn > how to bring my code up to the GNU Radio quality standards etc and put > the existing code in GNU Radio distribution. > > Further, can we add a spectra message type in GNUradio so that spectral > can be passed to different blocks? Spectra are real- or complex-valued vectors, and we already have that type. > To show that good progress has already been made, but still needs > quality integration into GNU Radio, > three figures are attached. Using an AIRSPY (10 MHz bandwidth) and GNU > radio, I’ve mapped the Milky Way Galaxy in Neutral > hydrogen (1420.406 MHz). It would be great if we can get this > functionality, with a few significant > enhancements, into the standard GNU Radio release. It sounds like the best way forward would be to consolidate these things into a radio astronomy OOT; I believe Marcus already has at least one of those. So, for GSoC, we'd need a more concise and specific project idea. In particular, we'd need a better survey of what already exists (and what not), and phrase this as a good project that can sensibly be done over a period of 3 months. Cheers, Martin _______________________________________________ Discuss-gnuradio mailing list [email protected] https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
