Spectrograph PointGrey GS3 at the Teide Observatory (Canary Islands).

Spectrograph PointGrey GS3 at the Teide Observatory (Canary Islands).

The first spectroscopic observations in the CEMeNt network were regularly performed in July and August 2013 on an experimental setup from Kroměříž. The experimental setup was used with a highly sensitive CCD video camera Watec 902 H2 Ultimate with 1/2″ CCD chip Sony ICX429ALL with an effective resolution of 720 × 576 px. FOV and resolution of the CCD chip allowed the use of holographic diffraction grating with density of 300 lines/mm, resolution of the experimental spectrograph was 56.8 Å/px.
The first fixed spectrographic system was put into operation at the Valašské Meziříčí Observatory in July 2014, it was in operation until 2016. The spectrograph was used with a highly sensitive CCD video camera VE 6047 EF/OSD. The camera was equiped with 1/3″ CCD chip Sony ICX673AKA with an effective resolution of 720 × 576 px, video was recorded in a standard PAL B signal at resolution 700 TVL. Field of view was 60° × 48°, system used to operate fast Tokina lens (f/0.98) with a variable focal length (3-8 mm). FOV and resolution of the CCD chip allowed the use of holographic diffraction grating with density of 500 lines/mm, resolution of the first fixed spectrograph was 32.8 Å/px.
Based on these experiments, two types of spectroscopic wide field systems are actually used in CEMeNt network. The older spectrographs (in operation since October 2015) use a highly sensitive CMOS video camera QHY5LII-M. The camera is equiped with 1/3″ CMOS chip Aptina MT9M034 with an effective resolution of 1280 × 960 px, quantum efficiency of the camera is 74%. The field of view was more or less 80° × 60° (at present it is 65° × 50°), system use megapixel (2.3 MPx) lens Tamron with a variable focal length (3-8 mm). The FOV and resolution of the CMOS chip enables the use of holographic diffraction grating with density of 1000 lines/mm, resolution of the spectrograph was 9.7 and 10.8 Å/px. Currently is resolution of the spectrographs QHY5II-M between 8.0 and 8.6 Å/px.

Comparative spectroscopy in the laboratory of the J. Heyrovsky Institute of Physical Chemistry.

Comparative spectroscopy in the laboratory of the J. Heyrovsky Institute of Physical Chemistry.

New spectrograph uses a highly sensitive CMOS video camera PointGrey Grasshoper3 GS3-U3-32S4M-C. The spectrograph is in operation at the Valašské Meziříčí Observatory (spectrograph VM_NW, instead of the old spectrograph with the VE 6047 EF/OSD camera) and at the Teide Observatory (Tenerife, Canary Islands). The GS3-U3-32S4M-C camera is equiped with 1/1.8″ CMOS chip Sony Pregius IMX252 with an effective resolution of 2048 × 1536 px. The CMOS chip used in the camera GS3-U3-32S4M-C has a high quantum efficiency (76 % at 525 nm) and high dynamic range (71.34 dB). The field of view is 60° × 45°, system uses VS technology megapixel lens (f/1.4, 9 Mpx) with a fixed focal length (6 mm). The FOV and resolution of the CMOS chip enables the use of holographic diffraction grating with density of 1000 lines/mm, resolution of the spectrograph in this configuration is 4.8 Å/px.
Recording and evaluation of individual meteors is maintained by the software UFO Tools (UFO Capture V2 or UFO Capture HD, UFO Analyzer and UFO Orbit), in the past (in 2014) the MetRec program was used for 3 months with a VE 6047-based system.
Since 2015, CEMeNt is cooperating on spectroscopic experiments with J. Heyrovsky Institute of Physical Chemistry (institute of the Czech Academy of Sciences) and Valašské Meziříčí Observatory. In order to better understand the chemistry and spectroscopy of meteor plasma, we implemented calibration free data processing in emission data evaluation and comparative algorithms for an analysis of reference spectra acquired in laboratory
experiments involving Laser Induced Breakdown Spectroscopy of Meteorite samples, Laser Induced Sparks in atmospheric gases and electric discharges, together with in-situ simultaneous measurement by meteor spectrograph and high resolution Echelle instrument. The results have been compared with real meteors spectra obtained from EDMOND. All of the measurements are realized with professional laboratory equipment at J. Heyrovsky institute in Prague.


REFERENCE ARTICLES

In case you use EDMOND meteor spectra database, please refer to:
[1] Kornoš L., Koukal J., Piffl R., and Tóth J. (2014a). EDMOND Meteor Database. In Gyssens M., Roggemans P., Zoladek P., editors, Proceedings of the International Meteor Conference, Poznań, Poland, Aug. 22-25, 2013, International Meteor Organization, p. 23-25.
[2] Koukal J., Srba J., Gorková S., Lenža L., Ferus M., Civiš S., Knížek A., Kubelík P., Kaiserová T. and Váňa P. (2016). Meteors and meteorites spectra. In Roggemans A. and Roggemans P., editors, Proceedings of the International Meteor Conference Egmond, Netherlands, June 2-5,  2016, International Meteor Organization, p. 137–142.

 

Ground map (central Europe) of spectrographs field of view at the Valašské Meziříčí Observatory, position of the station is marked (white circle).

Ground map (central Europe) of spectrographs field of view at the Valašské Meziříčí Observatory, position of the station is marked (white circle).