Good day all
Being a avid lightning photographer, I'm building a remote (self sustaining) weather station that will inform me of the current weather conditions, and an approaching lightning storm. General info will be sent via twitter with alerts sent via SMS.
I've got the most part of the Weather station working, including:
- Barometric pressure
- Temperature
- Humidity
- Twitter sending
- Connectivity via 3G modem
- Power supply system
What I still need to implement:
- Spherics detector - Unit is built, just need to interface - Lightning
- EMF - To build and interface - Lightning
- Field mill - To build and interface - Lightning
- Lightning direction unit -To build and interface - Lightning
- Anemometer - To buy/build and interface
- Wind Direction - To build and interface
As you can see it should be a rather interesting weather station, but I am looking for some advice on my ideas for detecting the lightning direction.
My plan is to make a array of 8 LDR/Phototransistor, pointing the out in a circle, one every 45 deg, and mounting them in a casing to make them only sensitive to light coming in from a particular angle. See attached picture. Using the Analog inputs of an Arduino Mega to check each of the 8 sensors rapidly and comparing the readings, thereby calculating and determining the direction of the light source.
My questions are:
A) Would this work?
B) Which would be better to sense the light of an approaching storm from a decent distance (say 20Km?), a LDR or Phototransistor?
C) Would it be linear to the amount of light "seen"?
I will program a bit of logic into the code, to try prevent false alarms, etc. Like it must detect lightning from say 2 detectors before sending out a alert.
Any other comments, crit or advice welcome!
Thanks in advance!
Justin
PS. Picture of Lightning over Durban - South Africa 
