1 / 10

All-sky camera of the ALFA project: common points and interests with the

All-sky camera of the ALFA project: common points and interests with the Wide Field Astronomical Observations E. Séran & M. Godefroy CETP, St-Maur. June 14, 2006 Paris. h, km. e. 300. ionosphere. 630nm (O). V. F. 200. 558nm (O). δn. 428nm (N 2 + ). E. 100. B.

torin
Download Presentation

All-sky camera of the ALFA project: common points and interests with the

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. All-sky camera of the ALFA project: common points and interests with the Wide Field Astronomical Observations E. Séran & M. Godefroy CETP, St-Maur June 14, 2006 Paris

  2. h, km e 300 ionosphere 630nm (O) V F 200 558nm (O) δn 428nm (N2+) E 100 B 1 10 electron E, keV Project ALFA (Auroral Light Fine Analysis) λ/2 844.6 (O) fpe hν λ λ/2 = 1-3 m SD • SCIENTIFIC OBJECTIVES • Study of the energy and material exchange inside the transpolar arcs • - Fine analysis of the light emissions in the ionosphere (altitude ~150-300 km) • Interaction of the energetic electrons with the ionosphere • Formation of the density irregularities in the regions of the precipitating electrons • Plasma motion associated with the field-aligned currents SD

  3. Project ALFA (Auroral Light Fine Analysis) INSTRUMENTAL OBJECIVES “All-sky“ “High resolution” “All-sky“ Angular resolution : - 90° < φ < 90° Horizontal resolution : ~ 200 m Horizontal covering : ~ 3000 km Filters: large frequency band R-G-B “High Resolution” Angular resolution :- 9° < φ < 9° Horizontal resolution :~ 40 m Horizontal covering : ~ 50 km Filters: narrow band of ~ 2 nm à 200 km

  4. All-sky S2 PRO Δt=6sec 1600 ISO W • Observations • - Emissions • - structure, dynamics, intensity • relative intensity in the RGB ranges • Absorption through the atmosphere (using stars) • Comets trails, moon, human activity etc. 500 350 800 km N 50 km E B G R hν 104 103 102 101 2-3 keV N2 427.8 R/(erg cm-2 s-1) O 844.6 427.8557.7 630777.4 844.6 nm N2+O (1S)O(1D) O/ O2 O/ O2 O 630 0. 1 1 10 E, keV

  5. Common points with astronomical observations in Dôme C • Observations • survey of the ionospheric emissions • survey of the atmospheric absorption • Data transfer (rate: <400 Mb/day for all experiments) • - ALFA’s ”quick-look”+ few images (Mb/day ?) • ALFA’s whole data base (~Gb/day !) • Technical points related to the extreme conditions • choice of materials (domes, insulations) • protection against the ice • access during the winter • - stuff training • etc.

  6. Proposal of installation in the SuperDarn shelter (1300m from the base) • Advantages • - Common scientific purposes • Minimum human light • Inconveniences • No access during the winter season (over 750 m)

  7. Electrical concept • Tension : 12V • - Power : 220 V / 1500 W Specific requirements • Dôme heating • Distance Camera - PC: 5 m • Mounting on the roof • Easy access from outside/inside

  8. St-Maur, 2006 Dôme C, 2008 Kiruna, 2005

  9. Proposal: Electric field and ice particles measurements in the boundary layer in Dôme C • Measured parameters • Vertical electric field • (influence on the transport of charged ice particles?) • - Electric conductivity • Flow of charged ice particles and charge distribution eE mg Q+ φ Q+ Q - ~ e-σt/ε0 u ~ 1/|ut| σ ~ 0.5 10-13 Mo m-1 φ ~ Q/C t=0 t u ~ 3 m s-1 t (growth) ~ 10 ms

  10. power Proposal: Electric field and ice particles measurements in the boundary layer in Dôme C Electrodes + electronics: Weight : ~ 500g Sizes: ~ 15x3cm electrodes ~ 0.7m each boom ~ 2.2L electronic box Power : ~ 0.2W + heating (TBD) ~30m TM/TC

More Related