Long_Focal_Length_Telescope_Specs_1905.pdf

DISTRIBUTION A. Approved for public release: distribution unlimited.

Long Focal Length Telescope Specifications for

Sensor Upgrade (Job 13911)

1.0 Scope

This document defines the specifications for a 16” f/3.8 telescope that will be utilized for MWIR/LWIR (mid-wave/long wave infrared) imaging. The telescope will be a Newtonian Astrograph reflector design having a 16” clear aperture and a nominal 60” effective focal length.

The image circle diameter should be at least 25mm. A summary of the telescope specifications is shown in Table 1. Up to three telescopes will be procured depending on the estimated cost.

2.0 Telescope Technical Details

2.1 Optical Tube Assembly

2.1.1 Primary Mirror

The primary mirror will be constructed using a light weight substrate. The reflective coating will be aluminum. The aluminum will be protected by a quartz or similar durable overcoat. The optical figure should be 1/25 wave RMS or better.

2.1.2 Tube Construction

The telescope tube will be fabricated to provide for thermally stable focus and boresight stability of 30 arc seconds or better. A closed tube design is to be utilized (open truss construction is unacceptable). Tube construction can be either aluminum or carbon-fiber. The tube exterior will be painted white to reduce thermal expansion when exposed to sunlight for long periods.

2.1.3 Focus Adjustment

The focuser assembly will include an absolute encoder and motor for remote control of focus during field applications. The drawtube diameter should be at least 5” to minimize the thermal background presented to the IR sensor.

2.1.4 Camera Attachment

Drawings of the 5 inch drawtube assembly will be provided as soon as possible following award of contract. AEDC will be responsible for developing a camera adapter using the interface drawings provided by the vendor. .

DISTRIBUTION A. Approved for public release: distribution unlimited.

2.1.5 Backfocus

The telescope backfocus should be greater than or equal to 4” from the exit plane of the drawtube (when positioned near the center of focus travel) to allow for utilizing existing AEDC camera adapter designs.

2.2 Other Requirements

2.2.1 Dimensions

The telescope tube diameter will not exceed 20”. The tube length will not exceed 54”.

The weight of the complete tube assembly will not exceed 85 pounds (excluding camera mounting hardware and/or mounting rings or adapter plates).

2.2.2 Mounting Provisions

The tube assembly will be provided with mounting rings or adapter plates for attaching to various tracking mounts. Detailed drawings of the mounting hardware (including hole patterns) must be provided by the vendor as soon as possible after contract award.

2.2.3 Delivery Time

The delivery time shall not exceed 6 months after receipt of order.

Telescope Feature Requirement Primary Mirror Clear Aperture 16”

Effective Focal Length 60” (1525mm) Focal Length Tolerance +/- 50mm

Optical Design Newtonian Astrograph Tube Construction Closed Tube

Tube Material Aluminum or Carbon Fiber Tube Finish White Paint

Focus Provision Motorized Drawtube Drawtube Diameter 5 inches

Telescope Tube Diameter <20” Tube Length <54”

Weight (excluding mounting hardware) <85 lbs Image Circle diameter >=25mm

Table 1 Telescope Specifications Summary