Flir

AN/AAQ-13 Navigation Pod FLIR

The FLIR has a wide field-of-view (WFOV) forward-looking infra-red sensor with 28 degrees field-of-view in azimuth and 21 degrees in elevation. The resulting images are superimposed on the outside scenery by projecting them on the HUD. The image is grainy, but the sense of depth is good enough to fly by in total darkness or the smoke of a battlefield. Rain, fog, or smoke however, degrade the performance of the system, since infra-red energy is greatly absorbed by aerosols or water vapour.

The AN/AAQ navigation Pod (although not fully implemented) greatly enhances the aircrafts all weather low-level capability, here is a guide on its use and limitations.

Firstly the Navigation Pod which houses the FLIR is mounted on the left port chin station (5L) and requires powering up before use, by means of the left/right hard point power on/off switches figure 1.

FLIR__Pod_PowerOn.JPG

Realistically the Pod requires power so that the environmental unit contained inside the unit can lower/raise the temperature to operating conditions to enable the FLIR to differentiate between hot and cold. Appling power to the Navigation Pod isn’t entirely necessary as this isn’t correctly modelled, it will work even if it isn’t activated.

It is important to note that its position on the fuselage being below that of the pilot provides a Field Of View (FOV), which is below that generally seen by the pilot. See figure 2. And thus the image imposed upon the HUD may require some alignment so that it corresponds with the image of the outside world as seen by the pilot.

FLIR_HUD_POD_VIEWS.JPG

Accessing the FLIR page on a MFD will enable you to align the FLIR image with your FOV.

FLIR_PAGE.JPG

The Page shown above, figure 2a, is the main menu page; here you will be able to access the FLIR, OSB 16. The FLIR page, figure 2b, is showing the FLIR off, it needs to be activated (shift-H) before any alignment can be made.

FLIR_HUD.JPG

Now you be able to see the FLIR image gathered from the Pod superimposed over the HUD and the FLIR page on the MFD will now display some options, which will allow you to bring into line the Pods FOV with that of yours as seen through the HUD.

FLIR_MOD.JPG

The Dec Fov OSB 20 & Exp Fov OSB 6 commands will allow you to expand (magnify) or decrease the image displayed. The Dec Pitch OSB 19 & Inc Pitch OSB 7 will move the FOV either up or down in the HUD, these are of most use when alignment is necessary. The corresponding values for these adjustments are also displayed on this page.

Using this function you can reposition the FOV of the Pod to view below and to the front of the aircraft see figure 3. This can be useful; allowing you to scan for hot targets whilst maintaining level flight, even at high altitude, as the image can be expanded considerably. Using the keystrokes for theses OSB commands you could program a rotary on the HOTAS (Hands on Throttle and Stick) to pitch up and down, or to “snapshot” from forward view to a view 30° nose down and back again.

FLIR_FOV.JPG

Now that we have aligned the Image displayed by the Navigation Pod with that of ours lets look at some of its uses and limitations. FLIR is mainly used to facilitate the pilot so that he/she can see directly to the front of the aircraft at night and has partial use under conditions of poor visibility; it can be used in conjunction with NVG’s to enhance the all weather capability by allowing the recognition of hot targets at night or when visibility is reduced.

FLIR_NVGs.JPG

Figure 4 is an image using the FLIR at night; here columns of vehicles made hot by their engines and exhausts are clearly visible displayed as “Black Hot” i.e. the hot areas are shown as dark or black regions.

ONLY_NVGs.JPG

Compare this to figure 5, which is the same representation this time using only NVG’s. Now the vehicles become much harder to spot using this night vision equipment alone which is only engineered to enhance available light. Both the FLIR and NVG’s (Night Vision Googles, activated with keystroke "N") are compatible and can be used simultaneously.

AN/AAQ-13 Navigation Pod FLIR Limitations

FLIR has limited use during periods of low visibility and poor weather as cloud and other weather conditions can disrupt the IR picture, also man made obscurants such as smoke, fire and decoys can prevent the use of FLIR. Figures 6 & 7.

FLIR_LIM1.JPG
FLIR_LIM2.JPG

In this case it would be necessary to descend below the weather or cloud base in order to distinguish hot targets, figure 8.

FLIR_LIM3.JPG

References:
LANTIRN Operations Guide by Wayne “Black Cat” Timmins
SP3 Manual
RP5 Manual
Falcon 4.0 User Manual
AN/APG-68 (V5) Operating Guide by Stephen”HotDogOne”French
F-16A/B MLU –The Pilots Guide
MCH 11-F 16 Vol5
Federation of American Scientist www.fas.org
Vipers in the Storm by Keith Rosenkranz

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