Technology Highlights

Tablet PC Annotation System (TPAS^TM)

The efficient collection of accurate data at the earliest stages of a preservation project is critical to the successful implementation of the project. Because decisions about final treatments or use are made based on the evaluation of existing conditions and quantities, the documentation of these conditions must be reliable and in a format that is usable by the entire project team, including design professionals, building owners and contractors. Over several years, Vertical Access (VA) has developed increasingly sophisticated methods of collecting digital survey data directly in the field during building investigations. The recent development of pen-based tablet computers capable of running AutoCAD provides greater potential for direct digital annotation.



Using TPAS^TMall data (including digital photography) directly on the tablet computer, in the field.

The system of documentation currently employed by VA in the investigation of building conditions is the Tablet PC Annotation System (TPAS^TM). VA developed TPAS^TM to input both graphical and numerical data directly into AutoCAD, on site, using tablet computers and digital cameras. With this system, existing conditions data are noted graphically in AutoCAD using pre-defined block libraries of material conditions. Graphical representation of the data facilitates interpretation and diagnosis of fault patterns and failure mechanisms. In addition, numerical data pertaining to the faults identified, such as crack length and width are also recorded, in attribute tag format.



The TPAS^TM equipment includes a tablet computer and a digital camera.

TPAS^TMcombines the utility of the AutoCAD program commonly used by architects, engineers and other design professionals with customized LISP programming to streamline quantity measurements and photographic documentation. Among the features employed using TPAS^TM that are native to AutoCAD are block libraries, blocks with attribute tags, AutoCAD design center, selective display of layers within viewports and attribute extraction to spreadsheet or database programs. To improve TPAS^TM functionality, VA has integrated several customized tools into AutoCAD using LISP programming. Custom programming developed by VA provides enhanced automation to the process of recording conditions by calculating the lengths and areas of conditions drawn and inserted into the AutoCAD drawing and by linking digital photographs and AutoCAD data blocks to automate the process of photo capture and cataloging.



Using TPAS^TM all data (including digital photography) directly on the tablet computer, in the field.



Attribute information containing such data as: type of material, class of fault/deterioration; severity, extent, or dimension of condition; quantity of the effected area; a hyperlink to a digital photograph, audio or video clip.

VA has completed several large-scale survey projects using TPAS^TM, including the Williamsburgh Savings Bank in Brooklyn, NY and the Tower of Independence Hall in Philadelphia. Over the course of these projects and others, VA has refined the TPAS^TM codes and continued to evaluate its equipment, a process that will continue in an effort to provide the best project deliverables possible.

More information on TPAS^TM in published articles including James V. Banta, Kent Diebolt and Michael Gilbert, "The Development and Use of a Tablet PC Annotation System for Conditions Surveys," APT Bulletin 37 (2-3, 2006): 39-45.