Camera Specifications computing focal length and f/#

[thiirane]

So I have come across a specification of a narrow field of view camera. The specification states
IFOV=30 microrad
FOV=2x2
resolution=<.1m at 1 km

If I assume a 1K sensor at 9micron pitch and an aperture = 3.7cm

I have resolution at .013 m

Chip size = 9.2mm

Focal length is 6.167E5mm?? can this be right? Also f/#=1.6E4

Do I have the formulas correct

f/#=Focal Length/Aperture

Focal Length=Aperture/2*tan(IFOV)

 

[Andy Resnick]

Can you provide additional information- for example, the field of view = 2x2 what- radians, degrees, other? Any specific information on the lens?

Alternatively, do you have a product ID/name?

 

[thiirane]

Hi Andy,

Actually the only thing specified is the IFOV, FOV and resolution at 1Km I think it is up to the supplier to design the rest. FOV is degrees. I assumed a sensor 1K sensor at 9 microns.

 

[Andy Resnick]

It's still not entirely clear- are you specifying a sensor, a lens, or an integrated sensor+lens? The IFOV and FOV specs define the sensor array size (I also got a 1k x 1k array), but the resolution spec involves a lens (which will operate at f/15 at a magnification of 1*10^-6, according the spec and assuming you are using visible light), and combining everything indicates a 400mm focal length lens, if the pixel size is 9um.

Note- imaging over 1 km distance is complicated by atmospheric distortion, you are unlikely to meet your resolution spec unless your application is able to avoid this. Some friendly advice- providing the OP specs to a supplier will result in an irritated supplier.