Ulrich Blum

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Breath-hold MR cholangio-pancreaticography using the RARE method was evaluated as a noninvasive alternative to direct cholangio-pancreaticography in 30 healthy volunteers and in 30 patients with various diseases of the respective duct systems. In contrast to 3D MR cholangiography, RARE MRCP generates projection images requiring a 4-s acquisition time and no(More)
The Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) has been operating since March 2002 onboard of the ENVIronmental SATellite of the European Space Agency (ESA). The high resolution (0.035 cm −1) limb-emission measurements acquired by MIPAS in the first two years of operation have very good geographical 5 and temporal coverage and have(More)
The importance of polar stratospheric clouds (PSC) for polar ozone depletion is well established. Lidar experiments are well suited to observe and classify polar strato-spheric clouds. On 5 January 2005 a PSC was observed simultaneously on the east and west sides of the Scandinavian mountains by ground-based lidars. This cloud was composed of liquid(More)
Atmospheric gravity waves have been the subject of intense research for several decades because of their extensive effects on the atmospheric circulation and the temperature structure. The U. Bonn lidar at the Esrange and the ALOMAR RMR lidar at the Andøya Rocket Range are located in northern Scandinavia 250 km apart on the east and west side of the(More)
Lidar system and radio-soundings were used to validate both air-density and low and high-resolution temperature profiles of the GOMOS instrument onboard ENVISAT-1 satellite. No bias greater than 7% was found for the air-density comparisons with lidar and there is a very strong global agreement. The conditions of the occultations have a large impact on the(More)
The validation results of MIPAS temperature, density and water vapour measurements using three different reference datasets is presented. The MIPAS temperature and density profiles have been compared to a statistical falling sphere model and to radiosonde data. The MIPAS water vapour measurements were validated using lidar data. Regarding the MIPAS density(More)
One basic need for all limb data products is the correct registration of the altitude for each measurement level. The validation of profile products has to comprise beyond the comparison of absolute values also an inspection of the altitude registration assigned to the measurement values. Lidar instruments are particularly suitable to perform this kind of(More)
Measurements taken in the framework of the Ground-Based Measurements and Campaign Database Subgroup (GBMCD) of the Atmospheric Chemistry Validation Team (ACVT) are compared to selected preliminary results of scientific algorithms to determine atmospheric parameters from measurements of SCIAMACHY. Presented are comparisons with algorithms to determine NO 2(More)