First results from the Biocams
J. Brunner
• Cameras on floor 1 and floor 5 together with an OM and an ADCP
• Floor 1 – 80m above sea floor
• Floor 5– 270m above sea floor– ~floor 13 normal line
Installation on IL07
Camera
AXIS221 vidéosurveillance
Night view capabilitiesView field up to 90 degreeSensitive into infraredView field & focus can be set manuallyDiaphragm & exposure time automatically / remotely controlled
Data outputEthernet
Power 12-24V, 5WControl of external device
IR Source
Absorption in water less than 1m – no interference with PMTs on other lines
~60 LED 850nm
Can be controlled (switched ON/OFF) by camera
Mechanics @ CPPM
Test setup for water testsFinal mechanics frame to hold cameraAnd IR source (not yet mounted)
Mounting on OMF (floor 5)Try to maximize overlap of field of view between camera and OM
Electronics from CPPM
CAMETH CAMPOW
Conversion of Ethernet signalsFrom electric to optic
Power supply and IR control
Combined tests with ISIT
ISIT IR AXIS
ISIT : intensified silicon intensifier tubeUniversity Aberdeen 1995, 20,000 EuroClaimed sensitivity ~ 10-6 lux
Bacteria sample
Combined tests with ISIT
Bacteria sample
AXIS
AXIS, IR ON
ISIT
Tests with OM
Camera and IR source850 nm
Box for laser calibration
OM with PMT
Image taken with PMT HV onAnd IR onCounting rate PMT ~ 10 Mhz Second IR source 940nmTo avoid interference with PMTs
Test with laser
laser
OMSplitter16x
Diffuser
Geometrical factor 0.1
Cameralens
100-1000 Hz
Integration variable
1cm2
Test with laserAXIS 1sec AXIS 1/25sec ISIT 1/25 sec
3.10-5 lux
3.10-6 lux
ISIT ~ factor 20 more sensitive ; AXIS better resolutionMissing sensitivity can be compensated by longer exposure timeWorst case scenario : isotropic light (as from K40)PMT 1MHz = 108 photons/m2/sec = 3 10-8 luxExpect to see pointlike signals at few MHz depending on geometry
Deployment July 2007
Floor 5Floor 1
ADCP Camera
OM
ADCP
Camera
OM
Connection Dec 2007Floor 5Floor 1
ADCPCameraIR flash
OMOM Camera
Data taking cameras
– Connected to Windows machine antbiocamdaq (IMP)– Run in self triggering mode (motion detection)– IR flash activated when triggered– Camera floor1 : large “excluded areas” to avoid self
triggering– Data saved on local disk– Triggered images manually copied to CPPM– Exposure time lowered from initially 2 secs to now 0.2
secs– Motion detection trigger tuned to maximize sensitivity
Data taking cameras– Manual triggers possible via web interface by switching ON IR
flash for few secs– Manual triggers are recorded (exmaple below)
– 2008-01-02 19:47:05 +0100 "IR floor 1 manual"– 2008-01-06 22:19:04 +0100 "IR floor 1 manual"– 2008-01-06 22:21:07 +0100 "IR floor 1 manual"– 2008-01-10 21:06:56 +0100 "IR floor 1 manual"– 2008-01-10 21:21:36 +0100 "IR floor 1 manual"– 2008-01-14 19:13:21 +0100 "IR floor 1 manual"– 2008-01-14 19:13:52 +0100 "IR floor 1 manual"– 2008-01-14 22:10:24 +0100 "IR floor 1 manual“
– First result : IR light totally invisible to PMTs (orientation, water absorption ?) for both wave lengths
– Alternative DAQ mode • always active (store all images)• IR always ON
– Useful to study currents, “snow” density
Data taking OMs & ADCPs
– Independent run control with customized clock, dfilter, dwriter
– Acou-clock provided by Max Neff to avoid interference with main run control
• (counter measure for clock broadcast commands)
– Data saved at Lyon as for normal runs• Only SummaryTimeslices written• Only ARS 0 read• 13msec Frametime • 20 hour runs : ~70 Mbytes per run
– Online monitoring : only 1 ratemon
Run Control
All processes can run on a single machine (currently pollux)
Examples of bursts
Time distribution camera triggers
15 triggers from floor 51 trigger from floor 1No striking correlation with burst fraction
Examples
2008-01-14 floor1 2007-12-30 floor5
Examples
2007-12-24 floor5 2008-01-19 floor5
OM floor 5 not anymore operationalUnder investigation
Examples
2007-12-10 floor5
Status
• Both cameras + IR flashes work well
• Lost 1 OM
• IR 940nm to far infrared to be useful
• Self triggering of cameras works fine
• Independent running with OMs works fine
• Sensitivity sufficient to see bioluminescent events
Future
• Continue data taking in self trigger mode• Develop external trigger (from OMs)• Improve self trigger for floor 1
– (trigger dead time, help needed from AXIS)• Try to resurrect OM floor 5• Analyze camera events (help needed)• Analyze L0 count rates (help needed)
– Burst shapes– Total charge seen by PMTs
• Possible data taking periods with light ON – to study sea currents– oscillations of lines– snow density