Prior to theresearch project

the multi-spectral photographic cameras used in the world have a small format （mostly 6cm ×6cm

so it is called 6MSP）

the 6 MSP could not be used for mapping; the "harmful absorption" of spectral photometry is great so that the image quality is not up to standard; Due to the small format

the processing work is great during flying and later period. This project uses aerial photogrammetric cameras of format 18cm × 18cm and 23 ×23cm which composed multi-spectral camera groups

and the spectral photometry which has no "harmful absorption" is constituted by "cut-off filter and special sensitive film" that enables the format of the multi-spectral aerial photography to increase by 9 times and 14.7 times more than 6MSP

and it allows"one photography-multiple usage"

e.g the photographs can be used for mapping and for resources investigation and environment monitoring. As there is no "harmful absorption" so the quality of multi-spectral image is higher

and can be used for visual interpretation and also can be input into compcter in order to do the objects classification and interpretation accurately. 18-23MSP is an efficient aerial remote sensing techniques.