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Remote
control systems
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There
are essentially five functions necessary to control the camera
remotely
1. Shutter - (including auto focus).
2. Zoom - (not indispensable because often a shorter
focal length is used).
3. Pan - continuous 360 ° horizontal rotation.
4. Tilt - vertical point on the horizon to the zenith
(minimum 90 °).
5. Monitor - displays the frame on the ground by broadcasting
the video signal.
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When
there is no ground control.
Some simplified KAP systems called "autoKAP" do not provide
ground control and operate one or more of these functions automatically.
The easiest "autoKAP" is the "Intervalometer" that consists
of an electronic device connected to the click of the camera,
and is user-definable, usually with intervals of several seconds.
In this case the pointing of the camera is fixed (usually overhead)
like the other functions.
There are also advanced "autoKAP" systems which go beyond the
click to activate at regular intervals. They pan and tilt the
camera according to a predefined sequence that covers all the
viewpoints of the visual field.
As you can imagine the picture obtained is completely random,
but amongst a large number of shots it is easy to find ones
that meet our requirements.
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Camera
Settings
In all KAP systems (with or without remote control) the
camera settings (time, aperture, ISO, white balance, etc..)
are set pre-flight.
Shutter priority is set between 1/500 and 1/1000 second. This
setting ensures photos even in turbulence that increases
rig movement.
There
are several commercial solutions for remote control of camera
range from "ready-to-use" to those that are personalized.
Usually KAPers prefer to build their own rig to suit their needs
by assembling the various electronic and mechanical components.
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How
does the remote control camera work?
The rig, as explained in the previous sections, is the equipment
that is hung to the kite and controlled by a special ground
station. All commands are given by radio. The kite line only
serves to control the kite's flight and has no control over
the rig. The radio streams are bidirectional.The video input
signal displays the camera frame and the ground station radio
output controls the camera.
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The ground control station consists essentially of two units: |
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The model-type radio transmitter (which operates on
the frequencies authorized for radio-controlled model)
sends commands to the control functions of the rig (click,
zoom, pan, tilt).
- The
Receiver with video on the monitor that constantly displays
high altitude camera frames in real time.
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airborne rig is composed of four main units: |
- The
radio-receiver that receives commands from the radio
transmitter on each channel and sends it to the appropriate
"actuators" (servo and camera interface)
- The
camera interface that allows communication between camera
and receiver and activates the focus, shutter and zoom
functions.
- The
unit pointing that allows the camera to rotate 360 °
horizontally and tilt vertically by two actuators connected
to the receiver
- The
video transmission that takes the video signal from
the camera and sends it to Earth for viewing on monitors
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It
should be noted that there are several remote control systems.
What we have just described is certainly one of the most popular
because it is made up of commercially available components and
materials, and is assembled personally. There are other very
effective systems that can integrate several functions into
a single preassembled component.
In the "Links" section you
will find several sites that sell ready-to-use remote control
systems and components for their assembly.
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My
Rig
RIG-1
RIG-2
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