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LIDAR'S TELESCOPE AUTO-ALIGNMENT SYSTEM FOR CTA. Auteurs principaux : Mr. PALLOTTA, Juan Co-auteurs : Dr. RISTORI, Pablo 1 ; Dr. OTERO, Lidia 1 ; Mr. CHOUZA,Fernando 1 ; Mr. D'ELIA, Raul 1 ; Dr. ETCHEGOYEN, Alberto 2 ; Dr. QUEL, Eduardo 1
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LIDAR'S TELESCOPEAUTO-ALIGNMENT SYSTEM FORCTA Auteurs principaux : Mr. PALLOTTA, Juan Co-auteurs : Dr. RISTORI, Pablo1; Dr. OTERO, Lidia1; Mr. CHOUZA,Fernando1; Mr. D'ELIA, Raul1; Dr. ETCHEGOYEN, Alberto2; Dr. QUEL, Eduardo1 Intervenant : Dr. RISTORI, Pablo1 on behalf of Mr. PALLOTTA, Juan 1.- CEILAP (CITEDEF-CONICET), UMI-IFAECI-CNRS (3351) 2.- ITeDA (CNEA-CONICET-UNSAM)
Outlook • Multiwavelength Scanning Raman Lidar. Main features. • New shelter-dome to host the lidar. • Remote Operation System: Principles • Auto-alignment Procedure: the hardware • Auto-alignment Procedure: the software • Auto-alignment Procedure: examples • Others: Spectrometric Box • Others: Scanning Structure • Others: Telescope Improvements • Conclusions
Argentine Multi-angle Raman Lidar Main Features: • Emission: • Nd:Yag laser Inlite II-50 from Continuum. Energy per pulse 60mJ @ 532nm. • Reception Optics: • 6 receptionmirrors: • Ø = 40cm • F=1m. With optical fiber Ø = 1 mm at its focus. • Detectionlines: 3 elastic and 3 Raman. • Elastic: 355, 532 and 1064 nm • Raman: 387, 408 and 607 nm 3
Shelter-Dome • Based on the idea of CLUE shelter, built from a standard 20 ft. shelter modified completely as is shown in the figures. • For open/close the shelter, hydraulic cylinders were installed and can be controlled manualy on site or remotely via WiFi.
Remote Operation System • The whole multiangle lidar is controlled remotely via WiFi link between the control PC and the lidar shelter. • Data-taking procedure highly automated.
Auto-alignment Mirror System. Algorithm(1) • Auto-alignment system procedure is based on tilting the telescope, acquiring lidar signal, and quantifying the overlap factor. • Due to the fact that overlap factor modulates the lidar function, alignment condition can be assured by evaluating the signal through a certain range. The best overlap will be attained when the signal reaches its maximum value over this range
Auto-alignment Mirror System. Algorithm(2) • Alignment is performed evaluating the mean of the lidar signal over a certain range.
Auto-alignment Mirror System. Algorithm(3) • The tilt angle of the telescopes is driven by a set of stepper motors, handled by a RCM2200 Rabbit System microcontroller.It has a built-in Ethernet interface with an integrated TCP/IP stack. This interface is used to link the Multiangle Raman lidar with the control lidar PC. • The telescopes are controlled by a self-alignment system, which is a cooperative procedure performed by PC software running from the acquisition module and connected via WiFi to a microcontroller.
Spectrometric box • Detectionlines: 3 elastic and 3 Raman. • Elastic: 355, 532 and 1064 nm • Raman: • Nitrogen: 387 and 607 nm (from 355 and 532). • Water vapor: 408 nm (from 355 nm). • Planned to be manufactured in collaboration of the Advanced Modeling Laboratory at CITEDEF with a sintering machine. This will improve deployment time, reduce the size, weight of the whole detection system.
Spectrometric box • Detectionlines: 3 elastic and 3 Raman. • Elastic: 355, 532 and 1064 nm • Raman: • Nitrogen: 387 and 607 nm (from 355 and 532). • Water vapor: 408 nm (from 355 nm). • Planned to be manufactured in collaboration of the Advanced Modeling Laboratory at CITEDEF with a sintering machine. This will improve deployment time, reduce the size, weight of the whole detection system. Same optics being used at Comodoro Rivadavia’s Lidar
New azimuth-zenithal scannign bench • System being build with Mechanical Department of CITEDEF. • Already tested, highly rouged and stable. • Max. azimuth/zenithal velocity: 5 rpm. • Max. azimuth/zenithal aceleration: 1,7 rad/s2
New azimuth-zenithal scannign bench • System being build with Mechanical Department of CITEDEF. • Already tested, highly rouged and stable. • Max. azimuth/zenithal velocity: 5 rpm. • Max. azimuth/zenithal aceleration: 1,7 rad/s2 Same unit operational at CITEDEF
Summary • Argentinean multiangle Raman lidar is already hosted in its shelter-dome and can be operated remotely via WiFi. • Lidar signals were taken with only one telescope. The rest of them rest to be installed in near future. • Rest to implement the new scanning bench and program the scanning software. • The data acquisition software is already operational, and few features left to be done.