TGP wh bh question

[DukeAngus]

i have noticed while flying on the caucus map in january (it was 10 celsius) while flying the f-16 and using the lighting pod in flir mode that the high voltage electric towers/ transmission towers you know the biggest ones that support the high voltage electrical wire on very long runs around towns and town to town.  the metal part of it is showing the same color as bmp's and ifv's. i was only hunting bmp's and ifv's that were driving in a convoy at the time i noticed the towers. it is to my understanding the reason why the ground armor is the color that it is, is because of the engines  are hot.  are the transmission towers really that hot? i could see that the actual wires themselves could be hot from the electricity running through them but the metal of the towers i dont see how they could give off the same heat of a vehicle's  running engine. i also noticed the same thing using the ir mavs.

i would be appreciated if someone could confirm or deny  my reasoning and  verify if this is how it should be in dcs.

[Deano87]

This is more than likely just because the power tower doesn't have a thermal map yet to work with the new FLIR renderer. I would expect/hope this would change in the future.

 

[Raptor9]

FLIR imaging works based on emissivity, not absolute "cold" or "hot". Everything retains, reflects, and emits thermal radiation at different rates, which allows infrared-based sensors to display the environment based on the different emissivity of the objects within the sensor's field-of-view.

This makes FLIR sensors very effective across a wide spectrum of environmental conditions, compared to NVGs that operate using light amplification.

[Furiz]

@Raptor9 I know FLIR is work in progress but those electric towers can not emit that much heat to be on pair with working moving vehicles. Same goes with fences etc...

[Raptor9]

7 hours ago, Furiz said:

 those electric towers can not emit that much heat to be on pair with working moving vehicles. Same goes with fences etc...

It's not about how hot the object is, it's about the rates of emission or reflection of infrared energy. Additionally, it also comes down to the ability of the specific FLIR sensor to distinguish and display the relative detections. If a FLIR sensor or its video output only has 5 levels of brightness between full white and full black, the temperature differences as they appear on a video display may not have the level of resolution that directly correlates with the actual differences in infrared emission/reflection rates. If a FLIR sensor and its video output have 20 levels of brightness between full white and full black, you will see a greater degree of difference across many objects; but again, that doesn't directly correlate with how physically hot or cold the object is.

As an example from real-life usage, by messing with the level and gain of a FLIR sensor, I can make it so everything looks like Cookies & Cream ice cream, where everything appears to be almost completely black or completely white, with little in between (even when using a sensitive, high-resolution FLIR camera). When this happens, it can often be hard to see whether the FLIR is set to White-Hot or Black-Hot, and therefore the FLIR needs to be re-optimized. A FLIR sensor may need to be re-optimized several times over the course of a flight as thermal conditions in the environment change. I'm not describing how the F-16's TGP or AGM-65 seekers function specifically, because I have no first-hand use of the F-16 or Maverick missile, but I have extensive use with FLIR systems in other aircraft. What I'm trying to say is that there is a lot more to these systems in how they display thermal images of the environment besides just the apparent temperature of "hot" or "cold" objects.

If I drive up the gain on a FLIR camera, where a running vehicle is already at it it's maximum brightness level in the video output, I can make it so a cooler object is at the same brightness level as a much hotter object, giving it an appearance of being at the same temperature. And while a lot of FLIR sensors have automatic gain control mechanisms in them, the sophistication and effectiveness of such functions vary, especially with older generation FLIR sensors. Even in DCS, I am often constantly adjusting the FLIR picture using manual level gain controls to get a better picture based on the video output. Only on the most sophisticated FLIR systems in recent years would you have automatic gain control logic that rivals the management of a human operator.

Edited December 1, 2022 by Raptor9

[Furiz]

Well I don't think a post is close enough in IR specter to a Vehicle to not be distinguished by FLIR sensor, from all the videos I could find only vehicles and buildings seems to be distinguishable from everything else since they emit highest lvl of heat. So with 5 lvls of brightness it shows vehicles the brightest, and the rest is dark. It is not showing something that is not emitting heat the same as vehicles that emit heat.

Few examples. altho youtube image quality is low.

 

[Raptor9]

As stated above, if you turn up the gain on a FLIR sensor, a lot of dissimilar objects can appear to be same brightness in FLIR sensors that have adjustable level/gain settings. I can't speak for how AGM-65 missiles should appear (which are what you linked in the post above), because I've never used them. But not all FLIR sensors are the same in sensitivity, resolution, or video output.

But I can tell you I have personally flown at night, in various seasons (summer/winter), in areas with high-transmission power lines while using FLIR to navigate at low level altitudes. And power line stanchions, fence posts, and other such objects out there are quite easy to see in FLIR (and I wasn't even using modern day FLIR systems). What is not easy to see is the power lines themselves until you get quite close. Which is why the power line stanchions themselves are probably the only thing that kept me alive on many nights.

[Furiz]

Ok I can't argue there I only have youtube videos and no personal experience

[DukeAngus]

if I understand correctly after doing a little more research,  metals can reflect infrared light, say from the a sun, that is the reason why they are High lighted compared to the background.  I found that metals reflects  a good amount of IR light,  snow is quite reflective itself. And  a reason why the towers and vehicles  are the same color is because the t-pod doesn't have many gain levels to distinguish between different amounts of light that it is picking up

it would be interesting to see if cloud cover or even during night flights would change any of this.

 

fyl the pics in the first post of the MFDs, the  gain/contrast or any of  those types of settings had not been adjusted, I spawned into the plane and used the tgp and mfds as is

[ASAP]

On 12/1/2022 at 1:07 PM, Furiz said:

Well I don't think a post is close enough in IR specter to a Vehicle to not be distinguished by FLIR sensor, from all the videos I could find only vehicles and buildings seems to be distinguishable from everything else since they emit highest lvl of heat. So with 5 lvls of brightness it shows vehicles the brightest, and the rest is dark. It is not showing something that is not emitting heat the same as vehicles that emit heat.

Few examples. altho youtube image quality is low.

 

These videos from old IR mavericks that are not looking in the same IR range as the targeting pod. Not a great comparison point