A self-referenced ambient radiation thermometer for determining a temperature of a blackbody object, the self-referenced ambient radiation thermometer comprising:
- a temperature stabilized detector that receives central radiation from a blackbody object and produces a detector temperature signal in response to receipt of the central radiation;
- a detector lens in optical communication with the temperature stabilized detector and optically interposed between the temperature stabilized detector and the blackbody object and that receives the central radiation from the blackbody object and focuses the central radiation on the temperature stabilized detector;
- a Lyot stop in optical communication with the blackbody object and optically interposed between the detector lens and the blackbody object and that receives scattered radiation from a collimating lens, stops the scattered radiation from reaching the temperature stabilized detector, and communicates the central radiation to the detector lens;
- the collimating lens in optical communication with the temperature stabilized detector and optically interposed between the temperature stabilized detector and the blackbody object and that receives the central radiation from the blackbody object and collimates the central radiation to the detector lens;
- a field stop in optical communication with the collimating lens and interposed between the collimating lens and the blackbody object and that receives the central radiation and peripheral radiation from the blackbody object, stops the peripheral radiation from reaching the collimating lens, and communicates the central radiation to the collimating lens;
- an optical chopper in optical communication with the collimating lens and interposed between the collimating lens and the blackbody object and that receives the central radiation and peripheral radiation from the blackbody object, stops the peripheral radiation from reaching the collimating lens, modulates the central radiation, and communicates the central radiation to the collimating lens such that the central radiation received by the temperature stabilized detector is modulated at a modulation frequency of the optical chopper;
- an objective lens in optical communication with the blackbody object and the temperature stabilized detector, optically interposed between the blackbody object and the field stop and that:
- receives the central radiation from the blackbody object and communicates the central radiation to the field stop;
- and
- a temperature-stabilized isothermal enclosure that provides a stable temperature and isothermal environment to elements disposed in the temperature-stabilized isothermal enclosure, wherein the elements disposed in the temperature-stabilized isothermal enclosure comprise:
- the temperature stabilized detector, the detector lens, the collimating lens, the Lyot stop, and the field stop.