Technical difficulties resolved, for now.
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.
We are experiencing technical difficulties …
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.
Three beams, 50% more fun!
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.
Everything you do will help us
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!