What could allow my world’s take on the Kaiju Gamera to sense heat while in his “rotating shell” flight mode?

[GodzillaLouise]

Ok, so the title isn’t the most self-explanatory thing this time. Let me explain.

In my world, which is mostly a fanfic world of Godzilla and Ultraman but has other franchises also mixed in, Gamera is a thing. Normally at this point, Gamera’s portrayed as a giant, bipedal, flying tortoise/turtle kaiju in a similar stance to Godzilla, and typically with a relatively similar body plan.

Similar to the version of Gamera featured in the 1995 to 1999 Heisei Trilogy of films, one thing I’ve decided for my version of Gamera is that he has two distinct flight modes:

For his first flight mode, he just retracts his legs into his shell and shoots rocket-like flame jets from the openings (please don’t ask about the biology of this particular segment, I have no idea where the jets come from in there), has high maneuverability, and is basically an organic fighter jet in the form of a giant turtle. However, this first flight mode is not the reason I’m here.

For his second mode, the one I want to focus on, he retracts everything (head, legs, tail, and arms) and shoots the fire from the openings for his legs and arms, rotating at extremely high speeds (which he can somehow survive the g-force of) to become a giant, flying, circular saw blade of death in the form of a turtle shell. Yet, he still has high maneuverability due to, as my document on him puts it currently, “an echolocation-like mechanism that works via sensing the heat signatures of physical objects and of energy projectiles / beams.”

In other words, Gamera can sense heat signatures while his head is retracted inside his shell and his shell is spinning at an insanely high speed.

Admittedly, at first, I thought I’d just go the route of having Gamera use his plasma manipulation abilities to sense the heat, but that doesn’t probably work for what I need, seeing as that’s mainly for converting plasma and partial plasmas (such as fire), not heat in general. So, I’m kind of stumped on how this works, cause I don’t think a pit viper’s pits are going to work inside a shell. Besides, even if they would, I highly doubt they would have any chance of surveying the entire area around Gamera while he’s spinning like a circular saw blade or old-fashioned film UFO.

By the way, I am also looking for more scientific/biological methods of explaining this. I’m fine with a pinch of handwavium, but I do want a semi-believable explanation for this.

[Visions1]

Firstly, maybe it doesn't have to be heat signatures. Maybe it's some form of light that can be sensed in the shell.
Or there are sensors on the shell.

[GodzillaLouise]

Firstly, maybe it doesn't have to be heat signatures. Maybe it's some form of light that can be sensed in the shell.
Or there are sensors on the shell.

Ok, so the first idea you brought up is interesting, though I’m not sure how it’d work. Would the sensors perceive this form of light in 3D or 2D? I ask because I feel like for whatever method he’s using to be effective as a means of perceiving the surroundings, it’d have to be perceiving everything spherically. In other words, a 3D / spherical radius.

To show why I believe that, here’s a link to a scene where one of the canon versions of Gamera’s rotating shell flight mode is on full display: https://youtu.be/8Bji31gt_rs?si=ErIgncv6Hh_6rfxM&t=541

Anyway, based on what I know, your other idea of heat sensors being on the shell’s exterior sound quite plausible for a spherical radius sense, though I’m not sure how they’d work.

[Ahzoh]

Anyway, based on what I know, your other idea of heat sensors being on the shell’s exterior sound quite plausible for a spherical radius sense, though I’m not sure how they’d work.

Probably in the same way an infrared-detecting camera would work.

[Wesl]

That’s a really cool idea for Gamera! For detecting heat while spinning, you might think about something like a thermal detection array inside the shell. I’m imagining it as a grid of infrared sensors or thermographic cameras that let Gamera sense heat around him. It’s a bit sci-fi, but it’s a neat way to keep things plausible without going too far into the realm of fantasy. I actually used a similar idea in a fanfic I wrote where a character had a rotating shield with sensors to detect enemies.