the trackyourdose app was developed by germany-based esooka and uses a mathematical model developed by scientists and meteorologists .
it uses a mathematical model developed by scientists and meteorologists from the physikalisch-technische bundesanstalt -lrb- ptb -rrb- in germany and the university oulu , finland .
since 1997 , ptb has studied the cosmic radiation at typical flight altitudes and used this to calculate radiation levels .