This service entails measuring the conductivity of the groundplane and any unwanted reflectivity of the proposed site. This is achieved by the "Reference Site Method" (RSM). Essentially the NSA antennas perform a site measurement with height scan over the National Physics Laboratory Groundplane at Teddington. An algorithm within the software attributes the correct factors to the antennas equating to zero error. This data along with UKAS certified differential test equipment form a traceable and accurate measurement system. This system is then used to perform an identical measurement on the customer's site. A comparison is then made with the NPL figures and reported out as a variance in dBs versus frequency. This procedure is recognized as a very accurate method of comparing other sites against the National Standard by the reduction of importing accumulated errors. An engineer will perform the test in both vertical and horizontal planes. The data will then be submitted in the form of a report which the customer can maintain as part of their site quality audit.