Airborne lidar measurements of PSCs with the aerosol-ozone-lidar OLEX
during
EuroSOLVE (Kiruna, Sweden)
LIDAR-Group @ Institut für Physik der Atmosphäre
DLR Oberpfaffenhofen, D-82234 Weßling
Tel.: 0049 +8153-283519
Fax: 0049 +8153 281271
FALCON research aircraft: Information available at the flight facility DLR Oberpfaffenhofen
Performance
Altitude [ft] | 10000 | 20000 | 31000 | 41000 |
Max. range [NM] | 1150 | 1500 | 1700 | 2000 |
Max. endurance [h:min] | 04:10 | 04:15 | 04:45 | 05:00 |
Max. Altitude 45 000 ft = 13 716 m
Max. Geschwindigkeit (VMO / MMO): 380 KCAS 0,865 Mach
Fluggeschwindigkeit für max. Reichweite: 410 KTAS 0,720 Mach
Startstrecke bei MTOW, ISA, MSL 2000 m 6562 ft
Research Objectives:
Fore- and hindcasts of meso-scale temperature-anomalies in the region of the Scandinavian mountain ridge. Based on the forecasts the FALCON will search lee-wave or synoptic PSCs and perform airborne lidar measurements of particle backscatter within the PSCs as well as up up- and downwind ozone. The OLEX Lidar will act as a PSC-pathfinder in order to guide the in-situ measuring ER-2 aircraft. Therefore real time information of PSC position will be supplied during the flight missions. This means close co-ordination with ER-2. Immediate feed-back from- and close collaboration with modellers (ETHZ, Univ. Leeds,...) during campaign and afterwards. Contour Advection simulations, validated by the long 2D-sections of ozone and aerosol as vortex air tracers, will serve to investigate the formation and erosion of filaments as well as dynamical exchange processes in the lowermost vortex.
Campaign |
PSCs above ESRANGE near Kiruna |
The OLEX Lidar:
The upward pointing aerosol-ozone-lidar (OLEX) makes use of a Nd:YAG laser emitting at 1064 nm and a XeCl-excimer laser emitting 308 nm for the ozone measurement with the DIAL technique. Frequency doubling and tripling of the Nd:YAG basic wavelength provides 532 nm and 355 nm channels. The received 532 nm signal is split into the perpendicularly polarised portions to determine the depolarisation ratio. With a repetition rate of 10 Hz for typical aircraft speed of 180 m/s the raw data resolution is about 18 m horizontally. Vertically the ADC sampling rate results in a resolution of 15 m. However, the compromise between signal/noise ratio and resolution leads to a processed resolution of about 1 km horizontally and 30 m vertically for the processed data. The receiving Cassegrain telescope (r = 17.5 cm) has 1 mrad field of view.
Biaxial optical system and beam path of the ALEX lidar. Left side: transmitter and crystals for frequency conversion, right side: receiver and data acquisition system. The system parameters are listed in Table 3. Full overlap of the laser beam and the receiver field-of-view is achieved after a distance of about 1 - 1.5 km. | View of the OLEX Lidar onboard the German Falcon aircraft D-CMET in flight direction. Front: XeCl-excimer laser, back: upward pointing telescope (blue), upper right side: Nd:YAG-laser. |
Crew:
AndreasDörnbrack;+498153282588- andreas.dörnbrack@dlr.de
AndreasFix;+498153282577- andreas.fix@dlr.de
HaraldFlentje(PI);+498153283519- harald.flentje@dlr.de
AlexanderMeister;+498153281817- alexander.meister@dlr.de