A useful guide from RICS on how to understand and avoid the potential dangers of scale factor.

The latest release (7 of 7) in the industry-standard RICS Geomatics Mapping Panel client guide series focuses on the complex and potentially confusing subject of map projection scale factor.

This client guide outlines the issues surrounding scale factor in this age of digital mapping and surveying, the relationship between scale factor and national mapping, local distortion and the issues when using GPS RTK systems.

The guide also contains an explanation of the concept of map projection scale factor and advice on appropriate survey reference systems such as 'snake' projections.

Although written with the UK market in mind, this (and many other) Mapping And Positioning Practice Panel (MAPPP) client guide is applicable globally.

The MAPPP client guides are designed to be used by professional and technical members of RICS Geomatics to help explain complex geo-subject areas to lay professionals, clients and other related professions such as architects and/or engineers.

The previous client guide (Scale – once it's digital isn't everything full size?) explained in lay person’s language issues around digital survey information and the relationship between scale and accuracy. This client guide also contained a new updated version of the 'Quick specification for topographical and measured building survey'.

The client guides also refer to the main body of official RICS industry standard guidance and professional information, now available free to all RICS members from www.rics.org/guidance.

The client guides are also very suitable for student use.

Other client guides
The full suite of client guides is available to download at www.rics.org/mappp.

The full set of seven RICS Geomatics client guides are:

• Virtually level – an RICS/Ordnance Survey guide on the change from benchmarks to GPS heighting
• An introduction to terrestrial laser scanning
• Reassuringly accurate – a guide to controlling accuracy
• Virtually Right – Networked GPS
• Developing a vertical reference surface for hydrography
• Scale – once it's digital isn’t everything full size?
• Map projection scale factor – how to understand and avoid the potential dangers of scale factor