Arecibo 2030

I no longer have any insider access to what's going on at Arecibo, but least this white paper proposing upgrades for the next ten years is fairly optimistic. It's not as ambitious as I might have expected, but after the hurricane damage that's not so surprising. I got an email about this and I may have contributed if I hadn't been at a conference with a 9am-7pm schedule and remote observations starting at 3:45am. Probably wouldn't have made a difference anyway, most of this is news to me.

The most immediate thing is how awesomely clean the dish is looking these days. I'd completely missed it, but they got $14 million for repair funding which includes the long-awaited task of cleaning the dish (there are better images on Google). But as they say, making the dish look nice doesn't mean it's good as new. Although the dish survived hurricane Maria, not least of the damage including a direct strike from a falling line feed, it's significantly warped. This means it still needs significant repair work to bring it back to full sensitivity, although (if I read this correctly) this is already funded through a $14 million hurricane relief fund.

Beyond restoration, the biggest improvement for the next decade should be ALPACA (Advanced L-band Phased Array Camera for Arecibo). This is a successor to the infamous ALFA instrument, but instead of having a measly 7 pixels as ALFA does, it will have the equivalent of 40. This improvement is possible because this uses a totally different sensor technology, and if and when it becomes operational, it will dramatically increase survey sensitivity and speed. Some people have described this as Arecibo's contribution to the SKA pathfinder telescopes being developed elsewhere.

Together with new receivers go the development of new back-end equipment that will give a much greater bandwidth. So not only will the telescope be able to cover more of the sky at once, but it will also be able to detect a greater range of frequencies at higher resolution all at the same time. That means more surveys can be combined, greatly increasing the discovery power per unit survey time. This will also make it possible, they say, to implement new ways to reduce the effects of radio frequency interference, though I can't say I understand how that works.

Finally, looking further ahead, the prospect of replacing the dish was often mentioned. In principle it should be possible to create a surface of the precision needed to reach frequencies as high as 30 GHz, compared to today's 10 GHz, so greatly increasing what the telescope can detect. That's a much bigger job, so the next decade will only involve a feasibility study.of this - but they're still projecting that the funding required would only fall into the "medium" category by the NSF standards. All in all - as ever - the level of funding required to fund Arecibo at a sensible level is very modest, and it remains the case that not funding it would be a damn travesty.

Astro2020 Activities and Projects White Paper: Arecibo Observatory in the Next Decade

The white paper discusses Arecibo Observatory's plan for facility improvements and activities over the next decade. The facility improvements include: (a) improving the telescope surface, pointing and focusing to achieve superb performance up to ~12.5 GHz; (b) equip the telescope with ultrawide-band feeds; (c) upgrade the instrumentation with a 4 GHz bandwidth high dynamic range digital link and a universal backend and (d) augment the VLBI facility by integrating the 12m telescope for phase referencing.