说明：  一本好的ENVI/IDL二次开发手册。包括ENVI编程介绍、波段运算、批处理、用户函数、常用编程工具、交互式函数等ENVI编程的各个方面。
(A good ENVI/IDL secondary development manual. including ENVI programming introduction, band operation, batch, user functions, commonly used programming tools, interactive functions,etc.)