Subscriber Discussion

Suggestions On IR Cameras In Caves?

RS
Reinhard Siegl
•Jul 26, 2015

Somebody has experience or suggestions regarding real-time observation of bats (in two caves)?

Caves to be fitted with several infrared (IP) cameras and IR illuminators, most of them in full darkness 24hrs.

The requirements are

  1. Video images to appear fluid and sharp
  2. Distance camera - bats is between 1.5 to a maximum of 10 meters in cave 1 and up to 100 meters at cave2
  3. The desired resolution would be a minimum of 2K / 1080p, optional 4K UHD or less.
  4. The frame rate should be at least 30 fps, if possible up to 120 fps.
  5. Zoom range between 10x and >25x in cave2**
  6. The following specifications are also desirable: ePTZ / vPTZ (because of the simultaneous availability of cameras on multiple monitors); true day / night; ONVIF conformance profiles S; Network port; Microphone Input

** There were until recently cameras with the following specifications in use: Raymax IR 30x (10 - 300mm F2.8) - RHM30Z1028GA-IR. A change to IP is wanted.

Any recommendations for camera types, which I could use for this purpose?
Appriciate your help!
Reinhard

JH
John Honovich
•Jul 26, 2015
IPVM

You mention there already were cameras in use. Did this include external IR? If so, what?

Also important, what is the width of the area you want to cover. For example, cave 1 max distance is 10 meters but is the max width 5 meters, 20 meters, 100 meters, etc.? This impacts choice of IR illuminators.

RS
Reinhard Siegl
•Jul 27, 2015
In reply to John Honovich

Thanks John! Cave1 camera widths are between 10 maximum 20 meter:

Only camera 4 has a distance of more then 10 meter, lets say 20 meter but in this area no bats are roosting but other animals like porcupine could be seen at night time.
It must be said that the final locations should be tried out by the installer.

Cave1 proposed layout of camera positions

Cave2 has a much different layout. Its more like a huge tunnel, therefore light will come in from the entrances at day time at least for CAM1 and CAM4:
http://mulupark.com/tours-activities/showcaves/deer-lang-caves/


Entrance cave2

Yes, cave2 had RAYMAX200 installed (range up to 300m?), this should compare to AXTON AT-120X-S.
AXTON recommended pulsed mode to avoid overheating and creation of non desireable biological growth on the lights, also would reduce power consumption for the solar powered cave1 installation.

A sketch of the camera positions in cave2:
layout cave2

U
Undisclosed #1
•Jul 27, 2015
IPVMU Certified

Reinhard, using external IR on bats in their natural habitat may be a bad idea. Edit: <if they are vampire bats>

Edit: <Some> bats are sensitive to much of the IR spectrum.

Vampire bats are sensitive to power densities (a measure of emitted energy) greater than 50 µW/cm2 at distances between 13 and 16 cm (a power density of 1.8x10−4W/cm2 corresponds to 50 °C). This was first determined by quantifying the temperature at which vampire bats could not behaviorally distinguish between heat emitting and room temperature SUs. A positive linear relationship exists between the energy-threshold of heat detection and distance from stimuli. Through mathematical calculations, at a distance of 8 cm, vampire bats should be able to detect humans who emit radiation of 80 µW/cm2.[3] Temperature threshold measurements were directly measured by stimulating nerve fibers of thermoreceptors in the nose-leaf and upper lip with a water-circulated brass thermode and recording the impulses/second at every 5 °C shift in temperature from 10 to 40 °C. - Wikipedia

What type of bats are these?

(1)
JH
John Honovich
•Jul 27, 2015
IPVM
In reply to Undisclosed #1

See this article for a guy who built an IR camera based bat house. I have no experience with bats or caves.

U
Undisclosed #1
•Jul 27, 2015
IPVMU Certified
In reply to John Honovich

I edited my post to Reinhard above.

RS
Reinhard Siegl
•Jul 27, 2015
In reply to Undisclosed #1

Luckely they are not belonging to the Vampire bat family, they are

Trident leafnosed bat (Asellia tridens)
Persian leaf-nosed bat (Triaenops persicus macdonaldi)
Lesser mouse-tailed bat (Rhinopoma hardwickii arabium)
Naked-bellied tomb bat (Taphozous nudiventris)
But thanks for your concern, I wouldnt like to be involved if it would harm anything.
Here is an excerpt of the biodiversity report done by a zoologist:

6.1.3 Cameras within the cave
The idea for fitting the cave chambers with a series of video cameras is fully
supported, provided their use, installation and maintenance conform to very strict
guidelines to avoid undue disturbance to the cave fauna and the cave formations.
Both human and bat eyes are sensitive to visible light in the range of 400 to 700
nm wavelengths. Near infrared is usually defined as 700 to 1400 nm, and is
invisible to bat eyes. Imaging in near infrared requires an infrared illuminator.
Thermal imaging uses far infrared with wavelengths of 7000-14000 nm, and does
not require illumination as it senses the bats body heat. However thermal imaging
is very expensive and does not give high resolution images of the bats behaviour.
Hence near infrared with illumination would be required in the inner chamber and
in the outer entrance chamber at night.
In darkness, bats use ultrasound echolocation and acoustic signals, and IR
illumination will have no effect on this system. However some near IR lamps also
emit some visible red light, and this potentially could affect the animals in the
cave, which are used to almost total darkness. Hence illuminators should be
carefully selected from those that emits IR above 800 nm and produce no shorter
wavelengths. It is also recommended that illuminators and cameras are used only
during limited times for visitors and as required for particular studies by
researchers rather than being permanently on. In the outer chamber, daylight
sensitive cameras could be used during daylight hours.
In addition to fitting the cave with camera equipment, it is also recommended that
the cave is fitted with a series of other sensors, to include air temperature,
relative humidity, air movements, ultrasound scanners (bat detectors), and
normal acoustic microphones. These will allow real time collection of environmental
and behavioral data which would add to the tourism and research interest. .....

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