Abstract : In the frame of atmospheric composition change related to human activities, homogeneous andcontinuous atmospheric measurements have to be performed. This is why a new observatory (calledOASIS for Observation of the Atmosphere by Solar occultation Infrared Spectroscopy) has beeninstalled on the roof of the University of Paris-Est in order to analyze concentrations and variations ofkey atmospheric trace species, such as ozone and carbon monoxide. Development of experimentalmethodology and adaptation of inversion code (PROFFIT) allow to retrieve total and partial columnsof these gases. Results are compared to different data from ground-based (SAOZ for O3), satellites(IASI, GOME-2, OMI, for O3, and IASI and MOPITT for CO) and from atmospheric modelcalculations (REPROBUS for O3 and MOCAGE for CO). Very good correlations were found,showing that a middle resolution instrument, such as OASIS is able to monitor atmospheric trace gaseswith a good accuracy. Then, thanks to a measurements campaign (April-May 2009), realized at Izaña(Tenerife, clear atmospheric conditions) observatory which is equipped with high resolutionspectrometer, we provide valuable information about the performance of various total column ozonemeasuring instruments from ground (Brewer) and space (IASI, OMI, GOME-2). All temporal O3 andCO variabilities (seasonal, day-to-day, diurnal and extreme events) observed at both sites, such asrespective high and middle resolution instruments capabilities were discussed in details.