1. All sky camera, Lidar, and Electric Field Meter for the ASTRI SST-2M prototype for CTA
G. Leto, R. Zanmar Sanchez, G. Bellassai, P. Bruno,
M.C. Maccarone, E. Martinetti
(for the ASTRI Collaboration and the CTA Consortium)
Leto et al. – 2nd AtmoHEAD, Padua – May 2014

2. The ASTRI Program … in brief
ASTRI, ‘’Astrofisica con Specchi a Tecnologia Replicante Italiana’’
The ASTRI Program is an Italian “Progetto Bandiera” funded by the Ministry of Education, University and Research and led by INAF, the Italian National Institute of Astrophysics.
Main goals: design, development and production, within the Cherenkov Telescope Array, CTA, framework and following its requirements, of
an end-to-end prototype of a Dual-Mirror Small Size Telescope, SST-2M, devoted to the highest gamma-ray energy region (1-100 TeV) investigated by CTA, to be tested under field conditions in 2014,
a SST-2M mini-array to be placed at the final CTA Southern Site during 2016, which would constitute the first seed of the CTA Observatory,
the mirrors for the prototype of the CTA Medium Size Telescopes, MST.
Leto et al. – 2nd AtmoHEAD, Padua – May 2014

3. The ASTRI SST-2M telescope
The prototype
… devoted to investigate the VHE region, TeV, in a wide field of view, 9.6° full FoV, making use of innovative technological solutions:
a dual-mirror optics Schwarschild-Couder configuration,
Leto et al. – 2nd AtmoHEAD, Padua – May 2014

4. The ASTRI SST-2M telescope
The prototype
… and:
a compact focal plane camera (50x50x50 cm3) based on Si-PMs sensors
managed by a specifically designed front-end electronics.
Leto et al. – 2nd AtmoHEAD, Padua – May 2014

5. The site for the ASTRI prototype
Serra La Nave (SLN)
The ASTRI SST-2M telescope is an end-to-end prototype that will be tested on field.
Serra La Nave
The ASTRI SST-2M prototype will be placed, at the INAF ”M.G. Fracastoro” observing station located in Serra La Nave on the Etna Mountain near Catania.
Latitude: ° 41’ 05” N
Longitude: 14° 58’ 04” E
Altitude: m a.s.l
After the verification tests, devoted to probe the technological solutions adopted, the ASTRI SST-2M prototype will perform scientific observations on the Crab Nebula and on some of the brightest TeV sources …
Leto et al. – 2nd AtmoHEAD, Padua – May 2014

6. Monitoring the atmosphere at SLN – Auxiliary Instrumentation
The site for the ASTRI prototype
Monitoring the atmosphere at SLN – Auxiliary Instrumentation
Qui aggiungerei la lista della strumentazione ausiliaria a SLN, in senso lato, (Weather Station, EFM, Lidar, All-sky camera, Pludix, UVscope, …) ponendo in evidenza quella di cui tratterà la presentazione stessa.
Da qualche parte c’era una slide di questo tipo … mò la cerco!
Leto et al. – 2nd AtmoHEAD, Padua – May 2014

7. The Electric Field Meter, EFM
Auxiliary Instrumentation at SLN
The Electric Field Meter, EFM
Developed by the INAF Radio Astronomy Institute (IRA),
contact Federico Perini
Field-Mill sensor
Cettina: cambierei l’ordine; nel titolo in grigio “Auxiliary Instrumentation at SLN” (o qualcosa di simile); nel sottotitolo in rosso “The Electric Field Meter” così da evidenziare meglio (bianco su rosso) i vari strumenti. Ho cambiato così tutti I titoli e sottotitoli seguenti; come ti pare?
Leto et al. – 2nd AtmoHEAD, Padua – May 2014 7

8. Auxiliary Instrumentation at SLN
EFM at work
Etna Eruption 23 November, 2013
Leto et al. – 2nd AtmoHEAD, Padua – May 2014 8 8 8

9. Auxiliary Instrumentation at SLN
EFM – SLN alarm output
Event 7 km far from station
Can issue alarms
NO distance/direction (3 EFM needed!)
Can detect lightning distance > 7 km!!
Leto et al. – 2nd AtmoHEAD, Padua – May 2014

10. Auxiliary Instrumentation at SLN
Jan storm
EFM – SLN output alarms
Alarm bits issued from software are weighted to create an alert to ASTRI SST-2M
First derivative
Signal +
Alarm bits
Cettina: questa slide è sicuramente da completare, no?
Can issue alarms
NO distance/direction (3 EFM needed!)
Can detect lightening distance > 7 km!!
Leto et al. – 2nd AtmoHEAD, Padua – May 2014

11. Auxiliary Instrumentation at SLN
Raman Lidar - AMPLE
Build for the VAMOS SEGURO project by
CNISM, Napoli (contact Nicola Spinelli)
AMPLE characteristics
Elastic channel at 355nm.
Polarization measurements available.
Raman channel at 386nm.
Raw spatial resolution from 30cm to 30m
Can be pointed from software
Leto et al. – 2nd AtmoHEAD, Padua – May 2014 11 11 11

12. Auxiliary Instrumentation at SLN
Raman Lidar - EARLINET
Part of EARLINET since 2013: atmosphere monitoring routinely carried out.
Leto et al. – 2nd AtmoHEAD, Padua – May 2014 12

13. Auxiliary Instrumentation at SLN
All-Sky Camera, ASC
SBIG All-Sky Camera 340C
Kodak KAI-340 CCD 640x480
Exposure time 50 microseconds to 180 sec
One image every five minutes
Leto et al. – 2nd AtmoHEAD, Padua – May 2014 13 13 13

14. ASC: Color = Bayer Filter
Auxiliary Instrumentation at SLN
ASC: Color = Bayer Filter
Leto et al. – 2nd AtmoHEAD, Padua – May 2014 14 14 14

15. Auxiliary Instrumentation at SLN
ASC: Cloud Detection
Statistics of cloud cover for the SST-2M site day and night.
Support SST-2M observations.
Leto et al. – 2nd AtmoHEAD, Padua – May 2014
R. Zanmar Sanchez and G. Leto – 8th ASTRI Collaboration Meeting: Marzo, 2014 15 15 15

16. Auxiliary Instrumentation at SLN
ASC- Thresholding
Is it right to ingore the Green channel?
Usually the 3 RGB channels are turned into one: R-B or R/B
(Long et al. 2006)
RGB turned into HSL and L is used (Souza-Echer et al 2006)
Euclidean Geometric Distance (Sylvio et al 2010)
Leto et al. – 2nd AtmoHEAD, Padua – May 2014 16 16 16

17. Auxiliary Instrumentation at SLN
ASC - Thresholding
Principal Component Analysis
Classified by eye 25,000 images into
clear sky, overcast, lunar phase, sun altitude.
sistema cartesiano, analisi delle componenti. Fasi lunari.coordinate altazimutali. Altitude = altezza
Leto et al. – 2nd AtmoHEAD, Padua – May 2014 17 17 17

18. Auxiliary Instrumentation at SLN
ASC - Thresholding
Principal Component Analysis
Eigenvector
Eigenvalue R G B
9.2e7
0.5
0.6
1.6e6
0.7
0.1
-0.7
2.9e4
-0.5
0.8
-0.4
sistema cartesiano, analisi delle componenti. Fasi lunari.coordinate altazimutali. Altitude = altezza
Leto et al. – 2nd AtmoHEAD, Padua – May 2014 18 18 18

19. Auxiliary Instrumentation at SLN
ASC - Thresholding
Principal Component Analysis
sistema cartesiano, analisi delle componenti. Fasi lunari.coordinate altazimutali. Altitude = altezza
Leto et al. – 2nd AtmoHEAD, Padua – May 2014 19 19 19

20. Auxiliary Instrumentation at SLN
ASC - Thresholding
sistema cartesiano, analisi delle componenti. Fasi lunari.coordinate altazimutali. Altitude = altezza
Leto et al. – 2nd AtmoHEAD, Padua – May 2014 20 20 20

21. Auxiliary Instrumentation at SLN
ASC - Thresholding
Future work
Leto et al. – 2nd AtmoHEAD, Padua – May 2014 21 21 21

22. Auxiliary Instrumentation at SLN
ASC - Star Counting
Find stars
Note big holes in the data.
Leto et al. – 2nd AtmoHEAD, Padua – May 2014 22 22 22

23. Auxiliary Instrumentation at SLN
ASC - Star Counting
Confront with a catalog
We need an accurate transformation between pixel and celestial coordinates
ZEA projection
Distortions modeled with 6 order polynomial series
Note big holes in the data.
Leto et al. – 2nd AtmoHEAD, Padua – May 2014 23 23 23

24. Auxiliary Instrumentation at SLN
ASC - Star Counting
Discard Outliers
Fit for the magnitude transformation
Note big holes in the data.
zeropoint
slope
Leto et al. – 2nd AtmoHEAD, Padua – May 2014 24 24 24

25. Auxiliary Instrumentation at SLN
ASC - Star Counting
Tiling
Leto et al. – 2nd AtmoHEAD, Padua – May 2014 25

26. Auxiliary Instrumentation at SLN
ASC - Star Counting
Leto et al. – 2nd AtmoHEAD, Padua – May 2014 26 26 26 26

27. Auxiliary Instrumentation at SLN
ASC - Star Counting
Leto et al. – 2nd AtmoHEAD, Padua – May 2014 27 27 27 27

28. Auxiliary Instrumentation at SLN
ASC - Star Counting
Leto et al. – 2nd AtmoHEAD, Padua – May 2014 28 28 28

29. Conclusions and Future Work
Auxiliary Instrumentation at SLN
Conclusions and Future Work
All Sky Camera: Thresholding
Try extra rotation to turn problem one-dimensional
Work cases with the moon in the sky
Sunset and sunrise
All Sky Camera: Star counting
Build our own catalog
EFM:
Deliver real alerts to ASTRI SST-2M software (dummy software already implemented)
Lidar:
Data taken during ASTRI SST-2M observation will be available to define the real sky condition
Leto et al. – 2nd AtmoHEAD, Padua – May 2014 29 29 29

30. The ASTRI Program http://www.brera.inaf.it/astri/
Leto et al. – 2nd AtmoHEAD, Padua – May 2014