Technical Exhibit 1 IR Detector Parameters.doc

Technical Exhibit 1

Detector Assembly Parameters for

RS-25 Line Scanner Detector Assembly

1.

Performance and Physical Parameters 1.1 This specification covers the performance and physical requirements for the detector assembly to be used in the RS-25 Infrared Line Scanner head. This instrument will be flown in an aircraft. The detector assembly will be comprised of two (2) photoconductive HgCdTe (mercury-cadmium telluride) detectors, spectral filters, and cold shield enclosed in a Dewar (see attached drawings), and allow two preamplifiers (government supplied and installed after delivery) to be attached via SMA connectors.

The overall idea of these specifications is to provide the USDA Forest Service Infrared Operations with a 2-color detector in the 3-5 um and 8-12 um band, that can resolve at infinite focus, a 1 to 1.25 milliradian “target”.

2.0

REQUIREMENTS

2.1 Spectral Requirements

The spectral range for each channel is defined by the detectors and the spectral filters. The cutoff wavelength of the detectors and the spectral filter characteristics should be chosen to maximize the response in each channel. The spectral range for Channel A shall be 3 micrometers (um) to 5 um (+/- 10%) when measured at the 3dB points. The spectral range for Channel B shall be 8 um to 12 um (+/- 10%) when measured at the 3dB points.

2.2 Detector Requirements

2.2.1 Detectivity and Time Constant

The broadband detectivity (D*) shall be 5 x 1010 cm-√Hz /W for Channel A and 4 x 1010 cm-√Hz /W for Channel B, when measured with an f/0.89 cone at 77°K. The scene temperature is assumed to be 273°K to 300°K. The time constant (rise time) shall be 750 ns or faster.

2.2.2 Detector Size

The instantaneous field-of-view (IFOV) requirements dictate detector elements that have active area dimensions of 0.165 mm (0.0065 inch) on each side (0.233 mm or 0.00919 inch diagonal).

2.2.3 Physical Spacing and orientation The two detectors shall be spaced as close together as possible, but be far enough apart so that the cone of energy reaching each detector is not vignetted by the filter for the adjacent detector (see attached drawing of Detector layout). The maximum allowable center-to-center spacing between the detectors is .889 mm (0.035 inch) (+/- .0001 inch).

2.2.4 Detector Operating Temperature

The operating temperature of both detectors shall be 77°K.

2.2.5 Cold Shield

The detector assembly shall be cold shielded. The cold shield, which may be used as the filter holder, shall be compatible with an f/0.89 cone of energy in the one-detector dimension and an f/1.1 cone of energy reaching each detector in the two-detector dimension (see attached drawing “Detector_FOV_layout_example.pdf” layout).

2.3 Filters

Spectral filters shall be used to define the spectral regions for each detector channel. The Channel A cold filter shall be antireflective (AR) coated, 3-5um, Silicon (Si). The cold filter for Channel B shall be AR coated, 8-12um, Germanium (Ge). The filters may be sized to conform to the mechanical configuration and shall be as thin as practical. The maximum filter thickness shall be 1.0 mm (0.040 inch). The filters should be “cold” and may be held in place by the cold shield.

2.4 The following data shall be provided for each detector in the delivered assembly:

1.)

Effective response area.

2.)

Field-of-view

3.)

Spectral responsivity over the spectral response of both Channel A and Channel B.

4.)

Black body responsivity at 500°K.

5.)

Time constant (rise time).

6.)

Noise Equivalent Power (NEP).

7.)

Detectivity (D*).

8.)

Cut-off wavelengths.

9.)

Peak wavelength.

2.7 Deliverables

The following items shall be deliverables as part of this task:

1.)

Dual detector assemblies including detectors, filters, and cold shield, as described by these requirements to be mounted within a cryocooled custom Dewar.

2.)

The data specified in Section 2.4.