The Beijing-1 microsatellite

launched on October 27th in 2005

is the first applied earth observing microsat- ellite of China.It is also one of the members of the international Disaster Monitoring Constellation（DMC）.Its total mass is about 167kg.The designed minimum operational lifetime is 5 years.Beijing-1 microsatellite applies DMC multispectral cameras with a high resolution panchromatic imager based on the standard of SSTL.After its launch

Beijing-1 had been tested and evaluated for several months.From January to March in 2006

the primary purpose of the testing work was to evaluate the performance of the sensors.This paper introduced the tested items

the experiments

the data sets

the meth- ods and the results.Based on the characteristics of Beijing-1 mierosatellite and other earth observing satellites

a compre- hensive specifications of on-orbit testing and evaluating was proposed firstly by this paper.According to these specifica- tions

four in-flight testing and evaluating experiments were carried out in Beijing

Wuxi

Hefei and in Baihu farm which is located in Anhui province.In the four sites

three simultaneous measurement datasets were acquired respectively:the Beijing-1 images

the in situ surface reflectance and the atmosphere measurements

and the geometric measurements of linear objects and other typical objects.Based on the data sets

the geometric performance

radiometric performance

spectral performance and general quality of Beijing-1 sensors and images were tested and evaluated.The results of some key parameters

such as the resolution of panchromatic camera

the modulation transform function（MTF）

the signal-to- noise（SNR）

the linearity and dynamic range of panchromatic and multispectral cameras were given in the paper.Judged by results of the four in-flight testing and evaluating experiments

Beijing-lmierosatellite exhibited a good geometric and radiometric performance.More experiments will be taken place

and more parameters will be measured to evaluate Beijing-1 microsatellite comprehensively.