We haven’t posted an update since March 25th and one volunteer pointed that out to me in a message and then asked: “What’s the word?” Well, it’s “follow-ups”… mostly. We’re finally going to start testing live follow-ups next week. We’ll be doing the testing in the background at first and until we’re certain that it’s working properly, you won’t be able to tell that we’re doing it and the “Followups” counter on your profile will remain zero. Once we’re sure it’s working, we’ll start updating the follow-up counters and let you know anytime a follow-up gets to a certain level. Early next week, we’ll also go live with some subtle, but very important changes: We’ll improve the waterfall display processing and we’ll be adding simulated ET signals. Read on…
Being able to do follow-ups is a unique and exciting SETILive capability. If enough users mark a signal that appears in only one waterfall diagram (and therefore a potential ET candidate), the ATA telescope can be commanded to immediately go back to collect and send us more data from that target so we see if it still looks like ET through our usual marking. If it still shows up in the same single beam, a second followup will be triggered and then basically “rinse and repeat” as long as it continues to look potentially ET. Anyone classifying signals when this happens will be getting the follow-up waterfalls for classifying as well.
When they are enabled, tested, and fully active with live notifications (hopefully next week), we expect first follow-ups to happen pretty often as you might expect since single-beam signals are not that unusual. Terrestrial signals can often appear in one beam since the amount of signal that leaks into each beam varies quite a bit and if the signal is weak, it might not be strong enough for us to see it leaking into two of the beams. The leakage can change quite a bit as the ATA adjusts its beams to track the celestial sources and as the terrestrial source (an airplane, satellite, etc. ) moves with respect to the ATA. So, if a terrestrial source happened to look ET in one set of waterfalls, it likely won’t look that way in the next set we get several minutes later when the geometry has changed between the ATA and the RFI source. So, most followups won’t go past the second level and we won’t be notifying you that a follow-up is in progress unless it survives the second set of markings. At that point you’ll know that we’re starting to track a potential ET and that will be quite exciting even though it’s very unlikely to continue to pass the following ET tests. If it does… well, now that could get very exciting.
We’ll be randomly adding simulated ET signals so that we can measure our detection capabilities. As soon as you finish with a classification having an artificial signal, we’ll let you know where the signal was on the waterfall. In order to make this measurement more consistent and useful and to improve your ability to see weak signals in general, we’ll also change the waterfall processing and display to give them a more consistent brightness scale. It should improve your ability to make out very weak signals even when there’s some stronger RFI there too.
The main thing you might notice with the new waterfall processing is that the background noise pattern of random bright and dim spots will be more consistent and a bit more “filled in”. We hope this will help you pick out weak signals better and more often. It might even help reduce our tendency to see signal patterns in the noise – I’m not sure about that, though. Part of this improvement comes from keeping bright signals from causing the background to get dimmer. A side benefit is that the dark banding caused by strong signals going bright then dim should be less severe. I already know that you’ll probably see some new artifacts in the noise background that the old processing took out and we encourage you to point these and other things out in Talk as you did with the old processing, especially if it makes classification difficult. When it goes live, I’ll create a new Featured Topic on Talk for you to post any comments about these display changes and the artificial ET signals.
The statistics we collect on your classification of these artificial signals in the presence of terrestrial RFI signals will eventually become part of a peer-reviewed and published scientific paper. So, it’s important for you to continue to make your best effort at marking all signals in each waterfall as well as those that might be ET. We need to know what else was in the waterfall to properly measure our collective detection capability in the presence of a variety of RFI signals.
Thanks for your continued participation and I hope you look forward to the SETILive going to the next level with live follow-ups as much as we do.
SETILive Science Team
Early this morning Jane Jordan diagnosed the problems (resulting from an improper termination of our observations yesterday) and fixed them. I’ve now added that ‘fix’ to my cookbook so in the future I can be more effective at supporting the observations. Why mention any of this here? Just to request your continuing patience as we modify our real-time software to enable SETILive and incorporate your assistance. Thanks.
Tonight (it’s all relative to where you are, and I’m in California) something unusual is going on with our SonATA observations. Since we started up a bit before midnight local time, Jon Richards and I have been babysitting the automatic SonATA (that’s SETI on the ATA) observing system. It started up on time from the observing cron files, but something is non-standard. Jon and I have spent the past few hours trying to figure out what’s going on – what changed – what might the error messages we’ve been receiving really mean???? For those of you familiar with software coding and embedded error messages, you can understand that error message XXX_XXXX doesn’t necessarily tell you what the REAL problem is. Jon (as brilliant as he is) and I haven’t been able to decipher tonight’s messages. Data are being taken and decisions are being made and we are continuing with our observing. However, when Jane Jordan, the particular wizard best suited to solving this puzzle, looks at the logs on Monday; she may tell us that tonight’s data are compromised and we should reobserve all of these targets/frequencies. Why wait until Monday? Why don’t we get Jane out of bed right now and have her tell us what’s really wrong? Our SETI team is tiny, and our observations take place EVERY day. We need to move forward with new ideas while we enable our ongoing observations. So at the risk of having to inform you, and the team, that tonight’s observations aren’t valid and will need to be redone, we are letting Jane sleep so she can be awake to help us improve SonATA and SETILive. Tonight, the SonATA system tells me that we are observing three targets simultaneously, but when I try to classify signals at SETILive.org, I am being presented with only one beam, not three. Welcome to the world of real observational science, and please accept my apologies for any “do overs” we need to do to get the job done.
We’ve enabled the third (and final) target beam at the ATA, so that means you’ll be classifying three Kepler targets and that will make it more likely that a signal you mark in only one beam is actually a “signal of interest” and worth making the ATA go back to that Kepler target for a followup measurement. This will become the norm (if all goes well). We don’t think you’ll have any problem marking that third target image in the same 60 seconds you’re used to and with a third image, that’s 50% more Kepler targets to classify each time, so you might just enjoy it 50% more than usual. Let us know here or even better, on Talk if you have anything to say about it.
With two beams, a weak signal appearing in only one target beam can mean that instead of coming from the target ET star system, it was a satellite or other interference but just a little too weak in the second beam for you to see. The sensitivity to interfering signals coming in from the side (in the ATA’s “peripheral vision”, instead of in the direction of the target) varies enough between the beams so that this can happen. With three beams “voting”, it’s less likely that one beam is that much more sensitive than both of the others and the interfering signal is more likely to show up in two of the beams.
Again, let us know if you have any comments here or even better, on Talk.
I’m Jill Tarter, the Director of the Center for SETI Research. Since we launched at TED last Wednesday, I’ve been reading what you’ve been writing. There have been a bunch of comments on SETILive about not knowing what to do or what to mark or whether you are getting it right. We’ll work on making the tutorial more accessible and more informative as you’ve suggested, and over time we will implement some better marking tools as you’ve requested – but the ‘getting it right’ part is a bit more dicey. That’s because we really don’t know yet exactly what ‘right’ is.
As Lou Nigra (thanks, Lou!) and the tutorials have described, the SETILive data that are coming from the ATA originate in the crowded bands; small portions of the terrestrial microwave window that we have historically skipped over. That’s because our SonATA system gets confused there – it detects LOTS of signals, but it cannot finish clustering them, and classifying them by comparing them to signals that are detected in the other two (or maybe one as is now the case) beams on the sky being observed simultaneously, or finish looking them up in a database of all the signals that have been tagged as RFI in the past week. Rather than conduct our observations with non-uniform sensitivity, or continuously restart software modules that have given up in exhaustion, we have chosen to ignore these crowded bands – at these frequencies we’ve been blind and deaf. Ultimately that might turn out to be the best strategy – after all, why are those bands crowded? They are crowded because they have been allocated to different types of terrestrial communications services. We are the ones making all those signals. Or are we?
IF (of course it’s a huge if) there is a technological civilization near enough to us – its distance in light years is less than half the time over which our technology has been transmitting at a particular frequency band – perhaps that civilization has noticed that the Earth is very ‘radio bright’ at certain frequencies. Perhaps it has transponded back a reply at the same frequencies, knowing that we would have receivers that work there. A bit more speculation suggests that their message may be crafted to be detectable against this background of terrestrial transmissions. With this scenario in mind, we could try to code and implement all sorts of clever, non-linear anomaly detectors that inter-compare the signals received from the multiple beams on the sky – but remember we are trying to do this in near-real-time. The detector has to finish this task significantly before the observations move on to the next frequency band, because the system still needs to match whatever the detector has found against recently detected RFI from other directions on the sky. We don’t know what we are looking for, but we do want to invoke logical constraints that insure that the signal is only coming from one direction on the sky and not many.
Before we throw a whole lot of new computing resources (that we actually don’t happen to have) at this problem, we should take a look at what’s actually going on in the crowded bands as a guide to what might be the most effective strategy – that’s where you come in! We are hoping to use the amazing pattern recognition of your eyes and brains to look for signals (patterns of some sort) that appear in only one beam and not in any of the others. We hope you can help us set up a sort of rogues’ gallery of signal patterns detected over the past week (fortnight, month, 3 days ??) that can be collectively ‘remembered’ to assess whether this particular signal pattern has been seen before from other directions on the sky. That’s why we want you to mark the RFI in multiple beams as well as any pattern that only shows up in one beam. And then if enough of you mark the same single-beam pattern (so we are fairly confident it’s real, not noise), we’ll decide that it’s an interesting candidate signal and follow up on it immediately. That means that instead of moving on to the next frequency in the observing sequence, we will reobserve in the same directions, at the same frequency. SonATA is still blind, so you will have to tell us whether the pattern persists – is it still there? Is it still only in one beam? If so, the next observation will observe at the same frequency, but looking at different directions. Is the pattern still there? Well, that’s too bad, it means it really was some form of interference and isn’t associated with the target we were pointing at on the sky. BE PREPARED – WE THINK THIS WILL HAPPEN A LOT. Just like your eyes have peripheral vision, a radio telescope has ‘sidelobes’ into which signals can scatter and be confused with signals entering from the direction the telescope is pointing. The sidelobes are complicated in the way they cover the sky; it may appear that a signal is coming from only one beam out of three, but moving ‘off source’ can reposition the sidelobes so that the interference is once again detectable.
But what if the signal/pattern persists when we reobserve ‘on source’, and disappears when we go ‘off source’? That’s getting interesting! We’ll start up a cycle of ‘ons’ and ‘offs’ that will stop when the signal fails to be detected, or not be detected, at the right time, or when we’ve completed five cycles. If the system successfully completes five cycles, then the team at the Center for SETI Research will be alerted and we’ll be right there with you using our eyes and brains to figure out what to do next. Since we’ve begun SETI observing on the ATA this has not happened in the less crowded bands that SonATA has been exploring automatically. Now that we are trying to probe the crowded bands, we’ll have to see how it goes.
By now I hope you are convinced that your efforts can only help us. There’s a slight chance that you just might discover a signal from another technology buried underneath all the terrestrial interference and we will all celebrate. But at the very least you’ll help us better understand what it is that humans are doing as they manage to look at complex patterns and isolate sub-patterns that are unique to one of multiple samples. There may well be neurologists or psychophysicists out there who already know that answer, but my team doesn’t. If we can learn from you, we can be better equipped to train future automated detectors. And if it turns out that this is not a task at which humans are particularly adept, well we haven’t lost anything. After all, our previous strategy was to ignore the crowded bands. There is only an up side to your participation.
Thanks for being willing to help out, and good luck!
I’m Lou Nigra and have the good fortune to be Project Scientist for SETI Live and I’d like tell you about what we’re doing and why.
The SETI Live project’s goal is to take the Search for Extraterrestrial Intelligence (SETI) into the large chunks of radio frequency spectrum previously made mostly useless by the human-made Radio Frequency Interference (RFI) that crowds them from sources like GPS satellites and mobile phone networks. We’ll do this by showing you radio frequency signals direct from the SETI Institute’s Allen Telescope Array (ATA) as they are received while looking in the direction of stars that according to the Kepler telescope (and sometimes our sister project, Planet Hunters) have planets where liquid water is likely and so have the best chance of hosting an ET civilization producing radio signals of their own. Not only that, we’ll be putting you “in the loop” – if enough of you see a potential ET signal in the same data, then within minutes, the ATA will be interrupted and sent back to take a second look. This is already pretty exciting on several levels – you’ll process SETI data fresh off the telescope, the telescope will be pointed at stars with promising planets, and if you identify something ET-like, it could trigger a follow-up measurement. Now, this is basically what the ATA computers normally do, so why bring a bunch of citizen scientists into the loop?
Cleverly conceived computer algorithms used by the SETI Institute are extremely good at identifying potential ET signals in the presence of simple forms of RFI or small amounts of it. They become confused and unreliable when too much RFI begins to make the data too complex and chaotic. This is where you come in. Maybe it’s because humans evolved in a basically chaotic world that our sight (and other senses) are so good at picking out of that chaos the patterns that are important to us at the moment. Because of this, we believe that the human eye… well actually the human brain, will be much better suited than a computer algorithm to finding the weak, but orderly engineered signals we expect to intercept from a distant ET civilization amidst the complex and sometimes chaotic background of RFI.
Aside from the very important contribution to SETI science of opening up new frequency spectrum to the search, there are other scientific results we expect to get from SETILive. For one thing, we don’t know just how weak an ET signal you’ll be able to identify. So, we’re going to evaluate this by occasionally inserting data with an artificial ET test signal and collecting statistics on the results. Don’t worry, we will tell you immediately after you’ve classified one of these that it had a test ET signal and whether you caught it or not. We also don’t yet know the best ways to visually present this data to users that will make it easiest to pick out ET-like signals. We expect this to evolve as the project progresses and we’ll evaluate how successful you are with different visualizations. We expect to publish the results of both of these studies so you will be contributing to some important signal analysis science. Some of this may also lead to improving SETI computer algorithms.
We’ll start with a simple display that is widely used and very effective throughout radio astronomy: The “waterfall” display. Here the data is shown to you in a set of images, each of which shows all the frequencies in a particular bit of spectrum coming from a particular Kepler target’s direction, the strength of each frequency, and also how this changes with time. We’ll also give you some graphical tools to identify signals with frequency patterns that could be of interest.
Welcome to this unique Zooniverse project! I’m very excited to be a part of it and I look forward to working with you all.
What Data Do You See?
On SETI Live you are looking at ‘live’ data from the telescope. Every second, SonATA (SETI on the Allen Telescope Array) reports the power measured in individual frequency channels that are 1 Hz wide. While the SonATA system is dealing with more than 20 million such channels, for each beam on the sky, SETI Live is concentrating on only a few bands of channels that are crowded with signals.
Each waterfall plot displays the power in each of 533 channels horizontally, with each vertical row being a new time sample. The most recently sampled data is at the top of the plot. The brightness of the pixels represents how strong the signals are.
There are two or three separate waterfall plots for each observation, because the SonATA system looks at different target planetary systems at the same time. If a signal is really coming from one of the targets, it should be in only one of the plots – this is the sort of signal that might be from ETI. If the same signal can be seen in multiple plots, then it is some sort of interference of RFI that is entering into what we call the telescope sidelobes. Your eyes have peripheral vision, and so does a telescope – that’s what we call sidelobes. It is hard to distinguish a loud signal in the sidelobes from a weak signal in the telescope beam. Looking at multiple targets at the same time helps us figure this out.
How Does the Crowd Find ET?
During the initial observations, signals that you identify as being in only one beam, having some non-zero drift rate, and never having been seen before, become interesting candidates to be real ET signals. So when the current cycle of data acquisition ends, SonATA will retune the telescope’s frequencies and look back at the same target and frequency to try to reacquire that signal again. But SonATA is still blind to the crowded bands and so you will have to help with this follow up.
If the candidate signal you found was changing frequency over time, SonATA will predict the frequency where it should now be found, and generate waterfall plots for you to observe. Is the same signal still there? Is it in any other beam? If the answer to the first question is yes, and to the second question is no, this candidate remains of interest. Otherwise it will be classified as being due to chance noise, or interference.
A candidate that’s still interesting automatically generates an observation ‘off-source’ in the next data acquisition cycle. These new data will be presented to you. Is it still possible to see the signal? If so, it is coming from somewhere other than the target we were looking at and is therefore interference. If it isn’t seen ‘off-source’ than the next observing cycle will look back at the target.
This automated on/off cycle will continue 5 times, or until the signal is identified ‘off-source’ or fails to be seen again while pointing on the target. After 5 cycles, SETI scientists are alerted and humans take over the logic of where to point the telescope next – this is a rare, but very exciting occurrence! You are still critical because you’ve been classifying this signal up to now and are the experts on recognizing it. We’ll all look together to figure out how to proceed and what other questions to ask.
We’re pleased to welcome you to the blog for SETI Live. We’re asking for the public’s help in searching for extraterrestrial (ET) in radio signals from space. SETI uses the Allen Telescope Array (ATA) and lots of computer power to search for these signals automatically – so you might ask why we need you to help us search the skies in SETI Live? The answer lies is the talents humans possess, and computers cannot quite replicate. With computers and human brains working together, SETI Live can do more: faster.
The researchers at the SETI Institute have spent years creating an automated search system called SonATA (SETI on the ATA). This system handles the hugely complex task of deciding what to do with the signals the ATA detects. The huge number of signals in a single observation means that even though it is very advanced, SonATA just cannot complete the various queries to classify whether or not the candidates are interesting before the next data acquisition cycle starts up.
In order to avoid uneven and unknown completion of signal classification, SonATA skips over many “crowded” frequency bands. We are literally blind to any ET signals that might be arriving at those frequencies. Overall, it’s only a few percent of the entire 1 to 10 GHz frequency range we are trying to explore systematically, but those might be the most important frequencies!
Faster processors will help, but we really need to better understand what signals are in those crowded bands, and what is generating them, so that we can help SonATA do a better job of classifying and finding any really interesting candidates buried underneath all this clutter. That’s where you come in. We want to use your eyes and brains to help us work through these crowded bands. We want you to tell us about all the signals/patterns you can see, and why you think they may be from ET technologies rather than our own.
You’ll have to be quick – the telescope will move onto its next target in about 90 seconds!
SETI Live has been created by the Zooniverse, the SETI Institute and TED, through the TED Prize to allow everyone to join the search. You can read more about the science on the main SETI Live site, and our quick tutorial will explain how to get started in analyzing the signals from the ATA. We don’t know how well this will work. We’ve never had an army of citizen scientists to help us before. Until now we’ve been blind to these frequencies. We want you to help us regain them, and see if there’s an ET signal hidden there. Eventually, we want to learn whatever tricks you use to do your classifications, so we can teach SonATA how to do it as well.
We think that SETI Live is going to be very interesting and fun! Join the search now…