Airborne infrared fire detection optical system with tilted porthole

Thermal infrared imagery techniques have been applied in the field of wild land fire management for many years. A kind of infrared system with a tilted porthole conformal to the ellipsoid prow underside the plane nose is presented. This design increases the range of the inner imaging system, reduces air drag and protects against damage. The paper analyzes the aberration characteristic of a tilted ellipsoid porthole, and brings forward an effective corrective solution to make the system achieve a − 30° to − 90° field of regard with an instantaneous ± 4° field of view. The ultimate performance indicates that the infrared optical system has met the detection requirements.