de.hamburg.icdc/amd.de.sups/rao.dlidCSM03.l1.any_2 en SAMD v2.2, https://doi.org/10.25592/uhhfdm.9902 FESSTVAL sups_rao_dlidCSM03_l1_any_2 Doppler lidar wind and gust data from FESSTVAL 2021, Level1 at Birkholz DOI:10.25592/uhhfdm.11227 Detring, Carola Deutscher Wetterdienst, Meteorological Observatory Lindenberg – Richard-Aßmann-Observatory, Lindenberg, Germany; CF-1.7 where applicable external NETCDF4 de 300 daily 1 This data is subject to the FESSTVaL data policy to be found at https://doi.org/10.25592/uhhfdm.9890 and in the SAMD Observation Data Product Standard https://doi.org/10.25592/uhhfdm.9902. Deutscher Wetterdienst, Meteorological Observatory Lindenberg – Richard-Aßmann-Observatory, Lindenberg, Germany Carola Detring Carola.Detring@dwd.de 2021-05-18 2021-07-15 0.33 none 30 Birkholz: 52.200 °N, 14.192 °E This is the Level-1 data at Birkholz of the data set that is described in this documentation: The data set contains two wind products: (i) vertical profiles of the mean wind vector and (ii) vertical profiles of wind gusts. The data set is based on Doppler Lidar (DL) measurements and it is available for three different supersites (Falkenberg, Lindenberg, Birkholz) operated during the Field Experiment on Sub-mesoscale Spatio-Temporal Variability in Lindenberg (FESSTVaL) covering the period May 17, 2021, to August 31, 2021. For quality assurance purposes, an intercomparison experiment of the eight DL systems participating in FESSTVaL was organized in Falkenberg between July 16 and August 09, 2021. This implies that no DL wind_and_gust products are available for the Lindenberg and Birkholz sites during this period. The comparison experiment in Falkenberg included operation of DLs in the system configuration applied to determine gusts (see below) – thus for this site the wind_and_gust product is available also for the period July 29 to August 09, 2021. Note that two additional wind and gust products are available for which a separate description is given: (a) profiles based on ultrasonic anemometer measurements at the 99m tower at the Grenzschichtmessfeld (GM) Falkenberg, and (b) profiles from the same lidar measurements but derived using a different retrieval algorithm (level2uzk). DL profiles extend throughout the lower atmospheric boundary layer from 90m up to a maximum height typically above 1500 m dependent on the atmospheric backscatter conditions. The DL measurements were based on a conically Doppler lidar scanning geometry with high temporal resolution (~3.4s for one full scan, azimuth resolution of approx. ~33 deg) and a constant zenith angle of 28 deg. The realization of such a scanning strategy was possible via the continuous scan mode option of the DL system with a number of accumulated pulses per beam Npa = 3000. Two different types of Halo Photonics DL systems were used at the three sites during the campaign: (i) a Halo Photonics Streamline XR with a range gate length of 48 m and Halo Photonics Streamline with a range gate length of 30 m. For the non-XR systems the focus was set to 500 m, for XR systems it is set to infinity per default. For more details concerning the scan configuration see also Steinheuer et al. ( https://doi.org/10.5194/amt-15-3243-2022). In total there are three DL data subsets provided (Level1, Level2dwd, Level2uzk): The Level 1 data are provided by DWD using the dl_toolbox (https://github.com/mkay-atm/dl_toolbox) and include both the instantaneous DL measurements and related values (e.g. radial velocity and signal-to-noise ratio as function of range gate, time, and azimuth direction) and relevant information concerning the system’s specific parameters which are either fixed by the manufacturer (e.g. wavelength, pulse repetition frequency, pulse length) or can be configured by the user (e.g. range gate length, number of pulse accumulation, focus). All data are organized in daily files. The original measurements cover the lower 2600m (non-XR systems) / 4200m (XR systems) above ground level. However, depending on the signal quality and the results of the product’s quality assurance, the availability of reliable data in this lower part of the atmospheric boundary layer may be limited to lower heights. Due to configuration changes, system updates or location changes, there are single days for which the data are either missing or not complete. Operational decisions on the measurement strategy during FESSTVaL and the availability of the instruments led to different measurement tasks of the DL systems during the experiment which implies that the data products at each site originate from different systems during sub-periods of the experiment. Due to the short sampling time per ray, regular time synchronization vs. a reference at prescribed intervals occasionally resulted in a jump back of the time stamp assigned to each vector of radial velocity data. We did not correct that since we wanted to keep the original level-1 data as they were provided from the instrument. HALO Photonics Doppler lidar (system_id: 172) 52.2 14.192 70 none none Short term observations Local observations Supersites RAO 100 2 azi ('time',) sensor_azimuth_angle sensor azimuth due reference point degree beta ('time', 'range') volume_attenuated_backwards_scattering_function_in_air attenuated backscatter coefficient m-1 sr-1 delv ('time', 'range') spectral width of detected signal m s-1 dv ('time', 'range') radial velocity of scatterers away from instrument m s-1 errdv ('time', 'range') error of Doppler velocity m s-1 focus () telescope focus length m intensity ('time', 'range') backscatter intensity: b_int = snr+1, where snr denotes the signal-to-noise-ratio 1 lat () latitude latitude degrees_north lon () longitude longitude degrees_east lrg () range gate length m nfft () number of fft points 1 npls () number of pulses per ray 1 nqf () nyquist frequency nqv () nyquist velocity nrg () total number of range gates per ray 1 nsmpl () points per range gate 1 nv ('nv',) pd () prf () pulse repetition frequency s-1 range ('range',) line of sight distance towards the center of each range gate m range_bnds ('range', 'nv') m resf () frequency resolution s-1 resv () resolution of Doppler velocity m s-1 smplf () sampling frequency s-1 tgint () total observation time per range gate s time ('time',) time Time seconds since 1970-01-01 00:00:00 wl () radiation_wavelength laser center wavelength m zenith ('time',) zenith_angle beam direction due zenith degree zsl () altitude m