This research was for in-flight SPOT calibration conducted in July

1995. SPOT HRV was calibrated by La Crau test site and on-boarding calibration methods. 65 CODE was used for test site calibration and reflectance retrieval of some ground targets. The calibration coefficient A & A’was calculated. The calibration results based on both methods were compared and analysed. The analysis results have shown that: （ 1 ） calibration precision based on test site is higher than that obtained from on-boarding calihration; （2） 65 CODE is practical and fast for calibration and reflectance retrieval; （3） there are system errors in both methods; （4） the uncertainty of calibration coefficients can be estimated by the retrieved reflectance

of some targets; （5） the reliability of calibration result is proved by the consistence in calibration precision range for both or more independent methods: （6） the calibration result difference for different calibration methods can be used to diagnose the sensor state and to correct inadequate method or some mistakes

and also to guide the applications.