AN/UAS-4 Infrared Surveillance System

Brooke Clarke 2010

MK-898/AAS-14A Optical Filter Kit
Related Equipment


Page started after acquiring the seven IR filters for the AN/AAS-14 Infrared Detecting Set.
For information on how it was used see Radio Direction Finding Ref 21: United States Air force Airborne Radio Direction Finding (ARDF) System South Vietnam 1966 - page 47 "Red Haze" ..."The Army Mohawk (Wiki) IR (AN/UAS-4) has a different micron range than the RB-57, is more capable of detecting intense heat sources and uses the full width of film. It also has a cockpit readout."
The key components are:
OA-7825/AAS-14A Control-Indicator Group
CY-4815 Cabinet
IP-808/U Terrain Display Indicators - 5" CRT
IP-807/U Calibration Indicator - 3" CRT
SB-2649 Switch Control Panel -
C-6822 Detecting Set Control
CX-11271 & CS-11272 Cables
OA-7827 Infrared Receiver Group
R-1386 IR Receiver
AM-4464 Preamplifiers - IR to video converter
CN-770 Displacement Gyroscope - roll correction
AN/USA-23 & AN/USA-23A Recorder Groups
MX-7186 Recorder - records image & slating data
MA-18/U Film magazines - 5" wide Kokak pan dacomatic film type No. 2467-SP934 FSN: 6750-825-0270
CY-4811 Film Transport containers
MT-3583 Mount
PP-4478 Power Supply & MT-3582 Mount
CV-2052 Signal Data Converter -
HD-723 Cryogenic Refrigarator & MT-3610 Mount
CY-4813 Preamplifier Transit Case
Minor Items
Recorder Group Heating Blanket
Cockpit Checklist
Ground Preflight Checklist

Description from Surplus Shed for their L3959 SET OF 7 MILITARY INFRARED/NIGHT VISION FILTERS
These were made by HRB-Singer Inc. for the military and used on an infrared surveillance aerial camera. There are seven filters total for wavelengths: 2.0-2.6 microns, 3.0-4.1 microns, 4.5-5.5 microns, 9.0-12.0 microns, and three labeled: 1 cut, 2 cut, and 3 cut. The anodized aluminum mounting is 35mm diameter on the top (clear filter diameter of 17mm), threaded on the bottom (OD) at 31mm. The entire mounting is 14mm thick and is knurled on the side for secure attachment. The filters can be easily removed (they are held in by three screws), and their diameter is 21.5mm x 1mm thick (could be mounted in our M2629D filter mounting & retaining ring). These were made to be used on the MK-898 AAS-14A, NSN# 5850-00-946-9837. Also labeled as "CY-4832". They appear to be unused but have been in storage for quite some time.

MK-898/AAS-14A Optical Filter Kit

from TM 11-5850-218-12 page 3-20.
CUT 1: 1.0 to 15.0 microns short wavelength cutoff
CUT 2: 2.0 to 15.0 microns short wavelength cutoff
CUT 3 3.0 to 15.0 microns short wavelength cutoff
I'm hoping to put these in front of some IR sensors to make a crude optical spectrum analyzer.
They are marked:
1 CUT, 2 CUT, 3 CUT, 2.0-2.8, 3.0 - 4.1, 4.5 - 5.5 & 3.0 - 12.0 (micrometers)

AN/AAS-14 Infrared
      Detecting Set IR FIlters
Table of IR wavelength bands based on sensor type:

Filter WL
Band Wavelength nm

400- 700

700 - 1,000
Near infrared Silicon
2.0 - 2.8
1,000 - 3,000
Short-wave infrared InGaAs & Lead Salts
3.0 - 4.1
4.5 - 5.5
3,000 - 5,000
Mid-wave infrared InSb, HgCdTe, PbSe
3.0 - 12.0
7,000 - 14,000
Long-wave infrared HgCdTe, microbolometer

12,000 - 30,000
Very-long wave infrared doped Silicon

AN/ART-41A Radio Transmitter & MT-2530 Mount


TM 11-5850-218-12 Operator's & Organizational Maint Manual, Detecting Sets, Infrared AN/AAS-14A & AN/AAS-14B & Transmitter, Radio AN/ART-41A (Airborne Components of Surveillance System, Infared AN/UAS-4A & Cable Assembly Sets Electrical MX-7268/AAS-14A & MX-7270/UAS-4A, 5 Aug 1966

TM 11-5850-217-15 System application of Airborne Components of UAS-14A.

Related Equipment

See my Optics web page


Surplus Shed - where I got these

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