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Geo-referenced Dwelling Frame Project

SiQ participated (as part of a consortium of three companies) in a pilot project commissioned by Statistics South Africa in the last quarter of 2005 which aimed to determine the feature use of all structures in the awarded municipalities. SiQ also participated in a second similar project that was awarded to the consortium at the end of 2006.

The project entailed obtaining satellite imagery for the areas in question or using the aerial photography provided. Ortho-rectification and other image rectification procedures were performed on these images. Then geo-referenced points were placed on all structures in the applicable areas. This was known as the office listing.

The points created were handed to the field teams who visited each of these points. Data such as owner name, number of households, type of structure and street address was captured. A photo was also taken at each of these points. +- 360 000 structures were visited during the 2006 project.

Fieldworkers were issued with GPS units connected to handheld IPAQ Personal Digital Assistants (PDAs) containing customized ESRI ArcPad software to capture the data. Capturing the data electronically contributes to more accurate information and improved productivity. The personal digital assistance instrument (PDA) software was developed in such a manner that it would maximise the Quality Assurance effort at the lowest level and thus minimize the errors and post-capture re-work that would be necessary.

At the centre of these processes, a system was developed to keep track of the various revisions of the data-files, but more importantly to streamline and assist with the quality assurance process. Each time that data-files (ESRI shapefiles) were uploaded into the system from the office listing team via the internet, quality checks were automatically performed on the data and error reports emailed to the applicable persons. A data-file was only forwarded to the field team once it was error free.

A similar process was executed each time that files were uploaded from the field and a further "cross-check" process was started once a match was made between an error free office listing and an error free field data-file.

The final deliverables to the client were also compiled from this system, which ensured uniformity and conformity to the specifications.

As part of the quality control process a technical standards document was compiled which all parties had to adhere to.

Valuable experience was gained in the project management of a project of this magnitude and working with personnel from various disciplines, e.g. remote sensing experts to fieldworkers.

"The personal digital assistance instrument (PDA) software was developed in such a manner that it would maximise the Quality Assurance effort at the lowest level and thus minimize the errors and post-capture re-work that would be necessary."