Question and Answers.docx

Questions from Vendors for Infrared Telescope System

1. Requirement N° 7: Request is for protected aluminum but no specific value for average reflectivity is given. Is there a requirement on this specific aspect or having protected aluminum coating is considered enough?

Response: Reflectivity of protected aluminum shall be greater than 93% at wavelengths between 1 micrometer and 2.5 micrometers. We are aware that the reflectivity dips to just under 86% at 800 nm and rises to 93% at 1 micrometer.

1. Requirement N° 11.2: Requirement states that “locations of the primary perimeter, central obscuration, and central obscuration supports shall be knowable…”. With respect to which reference shall the position of the quantities indicated in this requirement be known and with which precision? Also, what does "primary perimeter" refer to?

Response: The reference is the aperture mask located at the entrance pupil. "Primary perimeter" is the circumference of the circular outer edge of the primary mirror.

1. Requirement N° 23.2: Is ±360° azimuth range a mandatory requirement? Should that be the case, a cable wrap would be required. This would have some significant impact on the design complexity level, affecting procurement time and costs. For such a reason, it would be helpful to understand if a reduced ±270° rotation is acceptable

Response: Reduced +/- 270-degree rotation in azimuth is acceptable.

1. What is the maximum allowed shift in the focal plane for a star at infinity to the reference target at 100 meters?

Response: This shift depends on the optical design, and specifically on the f/#. Any focuser must have enough travel so that it can move to the focus point for the artificial star at 100 m. A faster system would have less shift, a slower system would have a larger shift.

The Government's telescope design (see VI. 3) is an F/5 system with a maximum shift of approximately 2 inches.

The shift must be less than 6 inches.

1. Requirement #24. Is an ASCOM interface acceptable?

Response: The PCs controlling the observatory will more than likely be running on Linux however the Government is not restricting the operating system to Linux only. The Government would consider other operating systems.

Concerning ASCOM, this interface is acceptable however it is the Government’s understanding that ASCOM Alpaca will work with Linux and ASCOM Classic will not.

ASCOM Alpaca is preferable.

ASCOM classic will not run on a linux machine.

We will consider bids with ASCOM classic (Windows-based)

1. Requirement #28. Is it for polar alignment or for optical collimation?

Can you please provide a more complete description of what is required here, for budget purposes.

Response: The alignment kit is for optical collimation and alignment of the telescope optical elements. Not for polar alignment.

1. Is the telescope mount to be altitude-azimuth or equatorial, or no preference?

Response: The Government prefers an equatorial telescope mount but would accept an altitude-azimuth mount if the strongest offer only provided for an altitude-azimuth telescope mount.