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