Raman Lidar for Meteorological Observations, RALMO – Part 1: Instrument description
- 1Laboratory of Environmental Fluid Mechanics and Hydrology (EFLUM), Ecole Polytechnique Fédérale de Lausanne EPFL-ENAC, Station 2, 1015 Lausanne, Switzerland
- 2V.E. Zuev Institute of Atmospheric Optics SB RAS1, Academician Zuev Square, Tomsk, 634021, Russia
- 3División Lidar, CEILAP (UNIDEF-CITEDEF-MINDEF-CONICET), San Juan Bautista de La Salle 4397 (B1603ALO), Villa Martelli, Buenos Aires, Argentina
- 4Federal Office of Meteorology and Climatology MeteoSwiss, Atmospheric Data, P.O. Box 316, 1530 Payerne, Switzerland
- 5Laboratory of Air and Soil Pollution, Ecole Polytechnique Fédérale de Lausanne EPFL, Station 6, 1015 Lausanne, Switzerland
Abstract. A new Raman lidar for unattended, round-the-clock measurement of vertical water vapor profiles for operational use by the MeteoSwiss has been developed during the past years by the Swiss Federal Institute of Technology, Lausanne. The lidar uses narrow field-of-view, narrowband configuration, a UV laser, and four 30 cm in diameter mirrors, fiber-coupled to a grating polychromator. The optical design allows water vapor retrieval from the incomplete overlap region without instrument-specific range-dependent corrections. The daytime vertical range covers the mid-troposphere, whereas the nighttime range extends to the tropopause. The near range coverage is extended down to 100 m AGL by the use of an additional fiber in one of the telescopes. This paper describes the system layout and technical realization. Day- and nighttime lidar profiles compared to Vaisala RS92 and Snow White® profiles and a six-day continuous observation are presented as an illustration of the lidar measurement capability.