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Announcement of Opportunity for RFP No. N251229

Ground Layer Turbulence Monitoring on the Mauna Kea Summit Ridge

Gemini Observatory
Issued: 24 August 2005
Requests for RFP Due: 9 September 2005

The Association of Universities for Research in Astronomy, Inc. (“AURA”), acting as the operator of the Gemini Observatory, intends to solicit proposals to conduct ground layer turbulence monitoring at Gemini-North on the summit ridge of Mauna Kea, Hawaii. A Request for Proposal (RFP) will be issued in September and sent to those institutions that submit a request to receive the RFP by the date given above. Requests to receive the RFP should be sent by email to Andrew Flach, Gemini Contracts Manager, at aflach@gemini.edu, and should reference “N251229” in the subject line. In the body of the email please give the name of your institution and the contact information (name, email, street address, and telephone) for the person who will serve as your single point of contact for this procurement.

The RFP will seek detailed proposals for conducting an atmospheric turbulence monitoring campaign on Mauna Kea, which is anticipated to last one year, starting as soon as possible. The total funding available for the monitoring campaign is USD 200,000, which includes funding for both direct and indirect (i.e., the equivalent of overheads) costs. Detailed measurements of the ground layer turbulence are needed for Gemini to properly assess the feasibility of constructing a Ground-Layer Adaptive Optics (GLAO) system for Gemini-North. A GLAO Feasibility Study has recently been completed based on turbulence data for Gemini-South, the results of which are available here.

Funding to build the GLAO system, subsequent to the completion of the turbulence monitoring study, has not been secured yet. The final decision as to whether or not to build a GLAO system for Gemini will not be made until the results of this study are evaluated and funding options for all proposed new Gemini instrumentation are better defined.

Preliminary Ground Layer Turbulence Monitoring Study Requirements

During the GLAO Feasibility Study, detailed calculations were used to estimate the performance of the proposed GLAO system as a function of wavelength, field position, and laser guide star configuration. The modeling results depended on the adopted atmospheric turbulence profiles for a range of conditions. The data used by the Feasibility Study team were those collected on Cerro Pachon at Gemini-South, since equivalent data for Gemini-North on Mauna Kea did not yet exist. Accordingly, this RFP will request proposals to collect atmospheric data for Mauna Kea subject to the following preliminary requirements:

  • Turbulence measurements will be made as a function of altitude, and quantified as the refractive index structure function coefficient CN2(z)
  • Measurements will cover a variety of sampling frequencies (continuously during a night, nightly for contiguous blocks of several nights, with blocks separated by weeks and months, to adequately cover seasonal variations throughout a year)
  • Measurements of the ground layer will have spatial resolution of 100 m or better, from the ground to an altitude of at least 1 km, and with temporal resolution of a few minutes.
  • Concurrent seeing measurements (quantified as ro, the Fried parameter) that sample the entire air column

A goal for the study is to measure the free atmospheric seeing concurrently, to better separate ground layer turbulence from higher altitude effects, and look for correlations between the two.

The proposing team must supply the instrumentation and software needed to execute the turbulence monitoring campaign. The team will be responsible for data analysis and interpretation. Gemini will take responsibility for obtaining the permits that will be required to install and operate the site monitoring equipment on Mauna Kea.

Please note that these requirements may be modified or expanded in the actual RFP and are only meant to give a general idea of the scope of the work. Do not rely on the requirements stated in this announcement in performing any work. Interested teams should not begin work on their proposals until they have received the actual Request for Proposal document, which will contain the final and complete requirements and specific instructions regarding the content and format of proposals.