Astropulse

[UBT - Halifax-lad]

Any one who is signed up to the BETA Test should carry on crunching, Astropulse is coming to town shortly at the same URL. Any one who hasn't joined is more than welcome to join and help develop this new SETI project when it comes out, currently the project is dealing with the back end of enhanced.

The current SETI@home application looks for signals that are narrow in frequency, but have long duration. That's one way that an extraterrestrial civilization can send a signal that stands up above the radio background noise. Another possibility is that they could put a lot of power into a short duration pulsed signal that has a wide bandwidth. As such a pulse travels through interstellar space, interactions with interstellar matter slow down low frequencies relative to high frequencies in a process called dispersion. This dispersion spreads the pulse out over time. If we know how much dispersion a pulse has experienced, we can correct for this effect. For an extraterrestrial signal we won't know how much interstellar matter the signal interacted with on its journey, therefore we have to try every possible dispersion measure. That takes a lot of computing time.

Astropulse is a SETI@home application that uses coherent dedispersion to search for pulsed signals. In addition to extraterrestrial signals we might see signs of evaporating black holes or discover new pulsars. You can read more about Astropulse here

[UBT - Timbo]

Any one who is signed up to the BETA Test should carry on crunching, Astropulse is coming to town shortly at the same URL. Any one who hasn't joined is more than welcome to join and help develop this new SETI project when it comes out, currently the project is dealing with the back end of enhanced.

I've forgotten how long I've been waiting for Astropulse to make it out into the daylight - they were talking about this LONG before BOINC came out....!

Originally thought it was going to be a separate application (Astropulse@home?) but it'll give us somethign new to crunch rather than spinning our wheels on all the same SETI data - a reminder for you - Arecibo hasn't been collecting ANY NEW data for some time.....months and months in fact..... That's why many of the SETI WU's we get are all years old - in my current cache I have some from 1st March 1999.....-but at least these are now being crunched by the SE application, so we might find something in these old WU's after all....we've not found anything yet...!

regards,

Tim

[UBT - Halifax-lad]

Originally thought it was going to be a separate application (Astropulse@home?)

I think I would probably like it if it were classed as a separate project and got its own server etc etc, but saying that it could always like the options WCG have for running the two projects they have.

Arecibo hasn't been collecting ANY NEW data for some time.....months and months in fact.

Don't forget any donations made are also going to go to a new data collector that needs to be built

Multi-Beam Data Recorder
We are developing a high speed data recording system to take advantage of the new 7 beam ALFA receiver at Arecibo. Conceptually similar to the SETI@home I data recorder, it has been redesigned with a number of improvements.

It is capable of taking data much faster than the current recorder. While maintaining the sampling rate and instantaneous bandwidth of the SETI@home I recorder, the new system is more than capable of taking data from all 7 beams (better sky coverage) at both linear polarizations (more sensitivity). The current recorder takes data from beam at one polarization.

The new recorder will be able to monitor the pointing coordinates of the telescope. When the telescope is tracking a point on the sky, the frequency band being recorded will be periodically changed. This will give us greater frequency coverage rather than redundant coverage of just one part of the spectrum.

The new recorder will monitor the receiver state and when the ALFA receiver is off (for example, when AO is transmitting), data acquisition will be idled in order to conserve tape resources.

The data recorder consists of front end hardware, a host computer, an array of high speed disks, and an SDLT tape drive. The front end receives the analog signal from the receiver, converts it to a lower frequency and digitizes it. The host computer receives the digital data, collates it with timing and pointing data and writes it to tape, using the disk array as a buffer. It also makes decisions on whether or not to take data and controls frequency stepping.

Since the raw data will be organized in a different manner, we will be developing a new SETI@home application in order to analyze data in this new format.

I just wish the Austarlians would get around to Southern SERENDIP

Southern SERENDIP was first connected to the Parkes Radio Telescope on 20 March, 1998 with the ability to scan eight million channels at once. This has now been upgraded to 58 million channels. The instrument 'piggybacks' onto surveys of the sky that the telescope is currently carrying out.

[UBT - Halifax-lad]

More reason to keep on going on this Test Project

Now that enhanced has been released we can get back to work on Astropulse. I hope to have new Astropulse applications and work-units out in the next few weeks. In the meantime we will continue to distribute enhanced work.