The lightning strike incidents to the minaret are not unusual since the interception positions can be predetermined by a method first developed by Professor Horvath of Hungary more than half a century ago. This method, which is known as the rolling sphere method (RSM), have been included in most national and international lightning protection standards published since 1970 (eg. NFPA780, BS6651, IEC62305).
In this method, an imaginary sphere is rolled over and around the structure (eg. minaret) to be protected (Fig. 9). The surfaces of the minaret that are at risk of being struck by lightning, and hence require protection, are those that come into contact with the imaginary sphere, such as the apex and the tips of protrusions along the sides of the minaret.