The CGR4 lightning sensor

Thunderstorm and Lightning Climatology of Australia

“…In Australia, these counters have been installed in Brisbane (27.5° S, 153.0° E) and Darwin (12.3° S,131.0° E), and were used for estimating ground, cloud, and total flash densities at those localities. A later generation CGR4 counter (Mackerras et al, 2009) use the same (or similar) type of aerial for detecting electric field changes caused by lightning as the CGR3 LFCs; the main difference between the two instruments is that the CGR4 LFC uses a microprocessor to implement the flash discrimination procedures, the counting of flashes and the display of registrations.…”

Lightning flash density 1995-2010 in Brisbane, Australia

“…This sensor was used from 1995 to 2004. The CGR4 Sensor (Mackerras et al 2009) was used from about 2004 on. The effective range is currently set at about 11.3 km for all types of lightning, giving an effective area of about 400 km 2 , so a flash density in km -2 yr -1 is obtained by dividing an annual count by 400.…”

“…A third form of vertical aerial, mainly intended for use at Bureau automatic weather station (AWS) sites, consists of a 3.15 m length of 50 mm diameter aluminium tube contained inside a nominally 50 mm PVC pipe about 5 m long with its base at ground level. At sites on level ground clear of nearby obstructions, such as Bureau AWS sites, the lower end of the aluminium tube is located 1.62 m above ground (Mackerras et al 2009). …”

“…The response of 1 PGF out of 22 GF agrees with the estimate of PGF being about four per cent of GF. The one CF is to be expected as the estimated error rate for signalling CF in response to a GF is about ten per cent (Mackerras et al 2009). The CIGRE 500 Hz sensor responded to 26 out of the 27 observed ground flashes.…”

“…This register was used during field tests to indicate the presence of lightning up to about 16 km away. The DF register indicated the presence of lightning up to about 100 km, based only on a burst of radiofrequency radiation (Mackerras et al 2009). …”