Lightning Detection at PAO

Lightning Detection at PAO
Julian Rautenberg, Lukas Niemietz
11. July 2014
Lightning Detection
Monitoring for Auger/AERA
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Thunderstorms have impact to data quality
Radio signal can be enhanced
Measuring Methods:
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E-Field Mill
Boltek StromTracker
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Lightning Detection at PAO
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E-Field Mill
Two systems installed (Campbell Scientific CS110)
Balloon Launching Station (BLS) and Central Radio Station (CRS)
Measures at ground
1 sec sampling
Lightning detection via jumps in
data
No spacial resolution
Comparison BLS/CRS show
only limited range
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Lightning Detection at PAO
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AERA-Stations
30-80 MHz
180-200 ns sampling →
better time resolution than LMA
Small baseline →
low spacial resolution
Only short time traces
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Lightning Detection at PAO
11.07.2014
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E-Field-Mill Data Analyses
According to S. Nehls for Lopes
Requirement:
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E-Field over Threshold (500 V/m)
Jump in data larger then
|∆E −field | > 2 · RMS1 min
> Ejump = 300 V/m
Change in slope larger then 40◦
Sudden discharge due to lightning
(|∆E −field | > 15 · RMS1 min )
15 minutes around found event are marked as thunderstorm
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CRS Data from 01.01.11 till 31.01.13: 78 Thunderstorms
BLS Data from 01.01.11 till 28.01.13: 266 Thunderstorms
26 at the same time
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Lightning Detection at PAO
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Lightning in E-Field Data
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Lightning Detection at PAO
11.07.2014
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Lightning in E-Field Data
In the Auger Monitoring:
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Lightning Detection at PAO
11.07.2014
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Boltek StormTracker
Sensitive in kHz-region
Semiprofessional system
Lightning detection up to ∼ 500 km
Time accuracy of PC,
GPS-Extension is under construction
Roughly estimation of direction
via fraction of N/S and E/W
polarization
Three systems installed in November
2012 in Argentina,
fourth at LM March 2014
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Lightning Detection at PAO
11.07.2014
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GPS Extenstion
ublox LEA-6T module
Read out via USB
Time Mark External Input
→ StormTracker Trigger
(delayed ∼ 32.5 µs)
Trigger delay
Offset between GPS-Modules
Trigger delay
Offset between GPS-Modules
600
Entries
Mean
RMS
500
17936
-1.436
15.1
gps1-gps2
gps1-gps3
gps2-gps3
400
Entries
Mean
RMS
χ2 / ndf
Prob
Constant
Mean
Sigma
80
70
60
1000
32.59
0.05489
29.31 / 30
0.5016
71.36 ± 2.82
32.59 ± 0.00
0.05449 ± 0.00131
50
300
40
30
200
20
100
10
0
-100
-80
-60
-40
-20
0
Rautenberg Niemietz (Uni Wuppertal)
20
40
60
80
100
0
32.3
32.4
Lightning Detection at PAO
32.5
32.6
32.7
32.8
32.9
Time [us]
11.07.2014
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Lightning detection
In the Auger Monitoring up to 2013:
only station-wise information
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Lightning Detection at PAO
11.07.2014
9 / 17
Time of Arrival Reconstruction
Use GPS timestamps of each detector
Fit Origin via time differences
Results in Position and Time of Lightning
Calculate total amplitude (north/south)2 +(east/west)2
Calculate cross correlation to increase timing quality
Rautenberg Niemietz (Uni Wuppertal)
Lightning Detection at PAO
11.07.2014
10 / 17
Time of Arrival Reconstruction
Distance in km from CDAS CS
Events per station for 01.03.2014: CO: 8250, MG: 4778, LL: 8506
Reconstructed lightning events: 260
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Lightning Detection at PAO
11.07.2014
11 / 17
Lightning detection
In the Auger Monitoring now: full lightning-reconstruction
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Lightning Detection at PAO
11.07.2014
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Lightning detection in PAOMon
Due to data-volume separated Lightning-information to new
DB: Lightning
DB Lightning contains 3 tables:
LightningDetectionLifetime Data filled for
uptime-information from the stations
LightningDetectionData Data directly filled from the
stations, as before
LightningDetectionEvents Data filled from the
reconstruction, position and time
Some instabillities i.e. connection from the stations to campus
in general could be recovered from the data stored at the
stations
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Lightning Detection at PAO
11.07.2014
13 / 17
Lightning Trigger for SD
Aim:
For Correlation Studies (Lightning/Cosmic Ray) a lower
energy threshold is needed
External SD Trigger for read out of single stations
How to:
Write data into db (including lightning detector traces as root
file for each detector, written as binary)
MySQL Trigger for search of coincident events
Call Time Of Arrival reconstruction (needs access to the root
files in db)
Send upd-packet containing the lightning information to
CDAS
Write reconstructed lightning event to another monitoring db
Rautenberg Niemietz (Uni Wuppertal)
Lightning Detection at PAO
11.07.2014
14 / 17
Boltek StormTracker Comparison to
SD-Lightning Flag
PMT-Cable works as antenna
One or more Tanks can be flagged → Position in Field
Very good time accuracy
Needs analysis → nor directly available
SD MG
SD LL
SD MG
Entries
205
Mean
-1.85
RMS
15.83
100
80
80
60
60
40
40
20
20
0
-150
-100
-50
0
50
100
150
SD LL
Entries
403
Mean
-15.08
RMS
60.28
100
0
-150
-100
-50
0
50
100
150
dotted: SD direction, dashed: StormTracker direction, continuous: SD-StormTracker deviation
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Lightning Detection at PAO
11.07.2014
15 / 17
AERA-Events with Lightning in
E-Field Data
19.01.2012 20:39:29 - 21:35:30
Cosmic Ray Measurements with 180 MHz sampling
Modification of standard analysis
Thunderstorm moves over AERA
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Lightning Detection at PAO
11.07.2014
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Summary and Outlook
Two lightning detection systems installed in Argentina:
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Boltek StormTracker
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E-Field mill
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High trigger rate (in Arg. much higher than in Wuppertal)
Use only coincident Events
GPS Extension
Lightning detection is possible
Both stations are implemented to the monitoring
Further studies for Data-quality cuts are needed
SD-Lightning Trigger is planed
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Lightning Detection at PAO
11.07.2014
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