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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?
Thanks
Glen
> 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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> Discuss-gnuradio mailing list
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Re: [Discuss-gnuradio] Radio Astronomy GSoC 2017 group possible?, Martin Braun, 2017/02/07