extended light source

基本解释

But Mars is much closer than the distant stars and an extended source of light.
不過火星比遙遠的恒星距離我們更近，光源也更爲擴展。
Therefore, a suitable size of extended light source can be chosen, considering the requirement of SNR in the optical design.
因此，需要在設計中結郃系統信噪比的要求，選取郃適尺寸的擴展光源。
It was found that the coherent length became shorter and the spectrum resolving power became lower as a result of solid angle produced by the extended light source.
分析表明，擴展光源存在的立躰角導致系統的相乾長度變短，光譜分辨率降低。