Advancements in Miniature Fixed-Point Technology for Infrared Remote Sensing Calibration: A Study on Unstable Melting Plateaus

With the quantitative progression of space infrared remote sensing technology, there is an emergent requirement for miniature fixed-point blackbodies that are traceable to SI. As a fundamental issue in temperature transfer, prior research has established that the characteristic temperature displays an approximately linear relationship with both heating power and ambient temperature, under quasi-stable melting plateaus. However, recent developments in remote sensing satellites and industry demands indicate a preference for working mode of unstable melting plateau due to superior efficiency. Therefore, in this article, the characteristic temperature under the unstable melting plateau was experimentally studied. The latest results show that this linear relationship weakens with the increase of the heating rate of the blackbody before the run-off point and presents a logarithmic relationship. We explored the reason for the weakening of the linear relationship with the heating rate through numerical simulation. Furthermore, a general characteristic temperature equation was established, which can effectively predict the characteristic temperature under different working conditions to cope with the complex space environment. This work provides a theoretical basis for on-orbit tracking of SI using miniature fixed-point technology.