English Heritage has a long tradition of applying, developing, researching and setting standards in survey. Specialist techniques, such as photogrammetry and laser scanning, provide the measured base data for a variety of heritage applications. These include conservation planning, condition surveys, decay monitoring, analytical recording, architectural/archaeological investigation and site presentation. They are a fundamental component to any heritage project. Often referred to as 'Metric' or 'Measured' survey these specialist approaches are categorised as either 'Direct' or 'Indirect' techniques.
Direct Survey techniques
These are typically used where there is a need for specific survey information, requiring data selection at the point of capture. They rely on the surveyor understanding the selection requirements of the project as well as the technical constraints on the technique. They are typically 'non-image' based and include:
- Hand Survey
- Theodolite/REDM Survey
- GPS
Indirect Survey techniques
These are typically used where there is a need for mass data capture or when the size and extent of the subject is too large for direct techniques to be appropriately deployed. They are based on image capture, be it photographic or laser-based, and typically require post-processing of the collected data to provide the specific outputs required by the project.They include:
- Rectified Photography
- Panoramic Imaging
- Photogrammetry
- Orthophotography
- Laser scanning
Survey standards and Specifications
Use of a defined standard will allow:
- an understanding of project requirements
- accountability
- data consistency
- management of client expectation
- focus on what an end-user needs from a technology
To ensure metric survey data is both appropriate and 'fit for purpose' English Heritage has developed a standard specification for metric survey. Now in its second edition this performance-based document encompasses all current metric survey techniques. The new title reflects a more generic approach to 'specification', as used by the Royal Institution of Chartered Surveyors (RICS), and now includes terrestrial laser scanning, which is increasingly being applied across the cultural heritage profession.
