Nevada Field Trip Days 1, 2, and 3 – The Search for a Quiet Location to Listen for the EOR Signal

The EDGES program under Professor Judd Bowman is searching for a site which would be nearly as remote and quiet (in the radio frequency ranges of 50-200 MHz) as the current site in Western Australia, but slightly more convenient to get to for testing and development.  The Global Epoch of Reionization (EOR) signal is very faint and must be carefully extracted from a bright sky almost 100,000 times greater in magnitude, so the fewer stray signals we pick up, the better our chances of successfully extracting the signal.

It was for this reason that Raul Monsalve (post-doc) and I (PhD candidate) packed a nice new SUV rental with our antenna gear last Monday and headed off to the middle of Nevada. It’s a long trip, so we were forced to spend the first night in Las Vegas. And on the second day, via the extraterrestrial highway (318), we arrived at the Gund Research Ranch operated by the University of Nevada Reno. (http://www.ag.unr.edu/about/facilities/gund_ranch.aspx). During the drive on the second day, we were encouraged by the weakness (and most of the time the lack of reception) of FM radio stations.

The ranch manager had a nice empty cabin available and was very hospitable. He showed us the boundaries of the ranch (100,000 acres when considering public and private lands) and told us of the hot springs in the area. One undesirable by-product of the hot springs is that the longer you let the cold water run, the hotter it gets, to the point of scalding. The ranch research focuses mainly on cattle, but people come to the ranch to conduct research on a variety of topics. He also pointed out several spots in the field that might interest us which didn’t have cattle roaming around that we might want to visit the next day.

On the third day, we took the packed SUV out onto a field on the ranch property. The rancher warned us to get out of there asap if it started to rain, because the road would get slick as butter and we’d have no chance of exiting. The road consisted of two tire tracks without vegetation amid a field that was a forest of thriving desert scrub brush plants. After going into the field for about a mile, and fearing we might not come back out if we drove much further, we found a place to set up our antenna and take measurements.

We brought 3 antennas with us and took measurements with all of them at this site:
1) A low band antenna sensitive in the range of 50 to 125 MHz
2) A high band antenna sensitive in the range of 80 to 200 MHz.
3) A small biconical dipole antenna sensitive in the range of 50 MHz and above.

After 2 hrs, we set up the low band antenna and took 2 hrs of measurements. We then switched antennas and took 2 hrs of measurements with the high band antenna. Because at 2 pm a few drops began to fall during the high band measurements, we decided to make the bi-conical dipole measurements in parallel to hasten our departure (we could do this because the dipole used a different piece of equipment than the low and high band antennas). If it really started to rain, there was no way we could shut down and get out of there in under 40 minutes, so we foolishly took our chances and completed all of our measurements. Luckily the few drops of rain stopped and we made an uneventful return to the ranch.

We are now looking at the data we recorded and will update you on the results in the next blog entry.

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