After about one year of maintenance (I have rebuilt all the circuit) the lightning radar, an invention of Frank Kooiman, is back on-line.
At the moment you can display the screens of the software on this blog, or on the site Lightningradar.net
This system was developed as a hobby alternative to the existing
commercial Boltek lightning detector. The advantages of the
lightning radar are the low cost (€40 and up) compared to the
Boltek (€350 to €600 depending on theversion),
the extreme sensitivity of the system, and the possibility of
joining the group system via the internet. Where Boltek
detectors can detect lightning up to a range of 500km, the LR
(lightning radar) has a range of 2000 to 3000km over land and
several thousand km over water (e.g. lightning in Florida, south
One disadvantage of the LR is that it is not a plug-and-play
system and therefore requires some knowledge
of electronics and
familiarity with a soldering iron. In practice, this is not
really a disadvantage since it means that
you learn a lot more about the science of detecting lightning.
The software functions as a single station showing the direction
and estimated distance, or connects with other LR stations via
the internet to perform a localisation function, displaying the
result (specific direction and distance) on a map. In addition
these maps can be uploaded to your website.
The electronics consists of
an amplifier which boosts and filters the signal from an antenna
and passes it to the soundcard of a computer (Line-in).
The lightning strikes are received using a frame antenna set at
10 kHz. At this frequency range the lightning sends impulses
over a range of several thousand kilometres. The antenna
consists of a frame, around which wire is wound in multiple
windings. The antenna measures the magnetic part of a wave and
has the advantage that it is less sensitive to interfering
electrical fields. With a single antenna, the lightning strike
can be detected but the direction cannot be measured. For this
reason a second identical antenna is mounted at 90 degrees to
the first antenna.
The direction can be calculated from the two
signals measured. It is still not possible to say for certain
the lightning strike occurred at one direction, exactly
opposite direction could also have been possible (+180 degrees).
This is also due to the fact that we do not know if the
lightning strike had a positive or negative charge. If you are
working with a single station, a third antenna is therefore
necessary to detect the charge and therefore the correct
direction of the strike. A single station cannot be used to
determine the exact position / distance of the strike. This can
only be estimated from the strength of the signal, since not all
lightning strikes have the same energy. Lightning Radar works in
a group of a number of stations and can therefore calculate the
correct direction and the position / distance using only 2
I have in test two ferrite antennas just like the ones used for
the TOA system. It's not simple to adapt them to the RDF hardware
but some good result is coming :-)
You can find information about
Lightning Radar on:
Use the following image to check the result from the first image.