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Re: [Discuss-gnuradio] Radio Astronomy GSoC 2017 group possible?

From: Glen I Langston
Subject: Re: [Discuss-gnuradio] Radio Astronomy GSoC 2017 group possible?
Date: Tue, 7 Feb 2017 17:03:53 -0500

Hi Marcus,

Thanks for your very quick response!  I will look at the links
you’ve pointed me towards.    Maybe much of what amateur radio astronomers
need is already available.

I agree that we don’t necessarily want “post-processing” code
in GNU radio.  But it would be good to include a few processing
hooks to enable realtime detection and writing of values
for later processing.

Do you think that a Radio Astronomy GSoC topic merits consideration?



> On Feb 7, 2017, at 4:45 PM, Marcus D. Leech <address@hidden> wrote:
> On 02/07/2017 04:20 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).
>> 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).
>> 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?
>> 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.
>> Observations are just recorded steadily, and spectra written every minute.  
>> I’ve left GNU radio recording sky brightness for a week
>> and the system was still functioning well when I returned.  After the data 
>> are gathered, the 1 minute spectra are
>> calibrated and averaged.  After averaging, the data are plotted and mapped.  
>> All data are ascii format.
>> 1) The first figure shows one 24 hour observation of the Sky, averaging the 
>> signals every hour.   The x axis is velocity of the parts of the
>> galaxy observed and Y axis is intensity.   The telescope (horn) was left 
>> outside for a day, pointed south with elevation of 29 degrees
>> above the horizon.  The different wiggly curves show different arms of the 
>> Milky Way Galaxy.
>> <Mail Attachment.png>
>> The thick blue and thick blue dashed lines are observations of the Center of 
>> the Milky Way galaxy, but one is 24 hours
>> later than the other.   These observations are made with a home made horn 
>> antenna, with about 3x3 foot square opening.
>> A few days of data were collected to observe much of the northern sky:  
>> Image shows Right Ascension on the X axis,
>> which is the time of day in astronomical coordinates.  A 24 hour period is 
>> shown on the X axis.   The Y axis
>> is Declination ( Roughly the Geographic Latitude) of the observation on the 
>> Sky.
>> <Mail Attachment.png>
>> The Dark red regions show the Milky Way galaxy.  The dark blue regions are 
>> away from the plane of our galaxy.
>> The top line is close to the north pole.
>> Final figure shows the Galactic Coordinate of the same data.   
>> The X axis is Galactic Longitude, with the center of the Milky Way at 
>> Galactic Longitude = 0, Latitude = 0.
>> The Y axis is Galactic Latitude, with the plane of the Galaxy at Latitude = 
>> 0.0, where most of the Hydrogen is seen.
>> <Mail Attachment.png> 
>> This is the very same data from the previous figure, but with coordinates 
>> converted to show the flatness of the galaxy more clearly.
>> Empty region is below the horizon and can not be observed from my back yard. 
>>  After the software is in GNU Radio,
>> hopefully someone in the southern hemisphere can fill in the gaps.
>> All the code to do the plotting is in python, but probably is not 
>> appropriate for GNU Radio.
>> What should be discussed is how to add a relatively few additional book 
>> keeping and data recording
>> features to GNU radio appropriate for astronomy.
>> Thanks
>> Glen
> Glen:
> Your results are excellent.
> What I will observe is that many of the things you want properly belong in 
> post-processing, rather than in real-time signal processing.
> Please look at the ccera GIT repository for relevant RA software written for 
> Gnu Radio:
> https://github.com/ccera-astro
> In particular, "spectro-radiometer" uses bog-standard Gnu Radio blocks and 
> does both real-time display of averaged spectra, and
>   derivation of continuum, and logs both on a regular basis.  There's also a 
> pulsar processor, which is still under heavy development.
>   But again, it all uses bog-standard Gnu Radio blocks, and the 
> relatively-new "Python Module" features.
> It's entering the territory of "wildly inappropriate" for the Qt GUI (or 
> WxGUI) FFT sinks to also do necessarily-custom data-logging.
>   Take a look at how spectro_radiometer does things efficiently in this 
> regard.
> Cheers
> Marcus
>>> On Jan 31, 2017, at 6:33 AM, sushil iyer <address@hidden> wrote:
>>> GSoC Proposal for GNU Radio
>>> GNU radio has been one of the best simulation software platform for 
>>> designing almost any communication system. In particular, our research 
>>> expertise exists in the field of software defined radio (cognitive radio). 
>>> The major utility of cognitive radios (CR) lies in developing a protocol 
>>> for efficient dynamic spectrum access. As of now, there are various blocks 
>>> available in the GNU radio companion which help in building different 
>>> cognitive radio specific systems but our interest is mainly focused over 
>>> the enhancement of Quality of Experience of CR users (secondary or 
>>> unlicensed users) through Machine Learning based efficient dynamic spectrum 
>>> access (DSA).
>>> In GNU radio, we intend to develop a comprehensive Learning based 
>>> (supervised learning like Artificial Neural Networks, Support Vector 
>>> Machines, Recurrent Neural Networks, and unsupervised learning like K-means 
>>> clustering) DSA library which would help the CR research community to 
>>> immediately design gamut of systems simply by utilizing the blocks present 
>>> in our library, viz. spectrum prediction, spectrum modeling, spectrum 
>>> characterization and many more.
>>> We have already published the efficiency of applied machine learning in the 
>>> context of cognitive radio scenarios thereby providing better and enhanced 
>>> QoE of CR users and our idea is to extend this horizon towards GNU radio 
>>> companion so as to better appreciate and qualify the CR research with 
>>> simplicity, robustness and efficiency.
>>> We would love to be a part of this program and contribute vitally towards 
>>> the community.
>>> Yours Sincerely
>>> Sushil Iyer
>>> B.Tech Third Year
>>> LNMIIT, Jaipur
>>> _______________________________________________
>>> Discuss-gnuradio mailing list
>>> address@hidden
>>> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
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