Lightning detector
Space-based detectors on satellites can be used to locate lightning range, bearing and intensity by direct observation.
Lightning detectors do not suffer from a masking effect and can provide confirmation when a shower cloud has evolved into a thunderstorm.
The second image shows that this happens when strikes originate in the anvil of the thundercloud (top part blown ahead of the cumulonimbus cloud by upper winds) or on the outside edge of the rain shaft.
Professional-quality portable lightning detectors improve performance in these areas by several techniques which facilitate each other, thus magnifying their effects: However, since RF signals and light pulses rarely occur simultaneously except when produced by lightning, RF sensors and light pulse sensors can usefully be connected in a "coincidence circuit" which requires both kinds of signals simultaneously in order to produce an output.
In early missions, astronauts used optical sensors to detect lightning in bright, sunlit clouds far below.
This can also be heard on sophisticated lightning detectors as individual staccato sounds for each stroke, forming a distinctive pattern.
Single sensor lightning detectors have been used on aircraft and while the lightning direction can be determined from a crossed loop sensor, the distance can not be determined reliably because the signal amplitude varies between the individual strokes described above, [11]: 115 and these systems use amplitude to estimate distance.
Because the strokes have different amplitudes, these detectors provide a line of dots on the display like spokes on a wheel extending out radially from the hub in the general direction of the lightning source.
But unless the sensor is close to the flash they do not pick up the weaker signals from IC discharges which have a significant amount of energy in the high frequency (HF) range (up to 30 MHz).
The difference of the group time delay of a lighting pulse at adjacent frequencies is proportional to the distance between transmitter and receiver.
Together with the direction finding method, this allows locating lightning strikes by a single station up to distances of 10000 km from their origin.
