Measuring Green Speed with Ios Devices.

Many golf course superintendents record green speed and use this data to tailor agronomic practices.  The stimpmeter is a device used to measure the speed of putting greens.  The iStimp is an application supported by iOS devices such as the iPod Touch, iPhone, and iPad which allows the user to obtain stimpmeter readings.  A comparison of the iStimp on the iPad, iPhone, and iPod touch has not been conducted.  The objective of this study was to determine the accuracy of the iStimp application compared to the USGA stimpmeter.  

Stimpmeter measurements were recorded on putting greens at two different golf courses with medium and fast green speeds according to USGA green speed definitions.  Stimpmeter readings were obtained with the three iOS devices and a USGA stimpmeter.  A research stimpmeter, which is known to produce equivalent results to the USGA device, was also included. 

The research stimpmeter produced similar green speed measurements compared to the USGA device when tested under medium and fast green speed conditions.  The iPhone overestimated and the iPad underestimated stimpmeter readings on both medium and fast greens.  The iPod touch produced similar stimpmeter readings on medium speed greens but overestimated on fast greens.  Stimpmeter readings from iOS devices are different than the USGA stimpmeter under the majority of conditions and comparisons between the two are not valid.