Mr. Phil Smith SBInet Chief Engineer Secure Border Initiative Arlington, Virginia 22209 Dear Mr. Smith, Thank you for your positive response. Perhaps we can start by my outlining concerns I am aware of for southern Arizona observatories and staff of other border state observatories may then add their specific concerns. 1. Increased light in the night sky -- a. One-half mile of stadium style lighting was added at Yuma/San Luis last month. b. The lighting at Bisbee/Naco has been extended to about 3.7 miles, increasing the number of light poles from 19 to 92. c. The Border Patrol has plans to build a permanent checkpoint on Interstate 19 at the highway's closest approach to the Whipple and MMT Observatories. With regard to outdoor lighting, the greatest damage is done by light which leaves a lighting fixture above the horizontal plane. This light goes directly to the night sky, overwhelming the starlight we try to study, and does no lighting work. Not only does the uplight not help anyone to see, it can create blinding glare for an observer and is a waste of energy. Another consideration is the amount of light. Even from the best shielded lighting fixture, an average of 10 to 15 percent of the downlight reflects off the ground and into the night sky. Good lighting practice is to light to the task. That is, use as much light as is needed, but no more. The Outdoor Lighting Codes in areas surrounding observatories recognize this by placing limits on the overall amount of light that may be installed per acre. The lighting experts on this email distribution can give you or your staff as much specific information about lighting fixtures and design as you wish. 2. Radio emissions -- 1. The tethered aerostat (airborne radar) at Ft. Huachuca, Ariz., long-ago modified its transmission pattern to avoid interfering with radio telescopes at the Kitt Peak Observatory site. I have heard second-hand that the plans are in the works to greatly increase the signal strength and possibly drop out the null zones in its transmission. If true, this would directly affect radio telescopes sited on Kitt Peak and on Mount Graham. If the signal strength is high enough, the radio waves could cause interference with the cameras and other electronics on optical telescopes as well. Because of this, the NEXRAD weather radar located east of the Whipple and MMT Observatories blinks off its transmission when pointing at the observatories on Kitt Peak, Mt. Graham and Mt. Hopkins. The list here only describes the nature of our concerns. We do not know the scope of SBI projects and, at this stage, you may not know either. No matter, we do wish to work with you so that you can accomplish your task with the least harm to ours. Please let us know the best way to proceed. Regards, Dan Brocious Smithsonian Institution Fred Lawrence Whipple Observatory
Possible additions to the border near Nogales are shown in views of San Diego, CA and Yuma, AZ (W of Nogales on the CA border). We plan to work with DHS and BP to minimize the impact of any lighting at the border on the night sky and of possible radio emissions on FLWO equipment.