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With the shift towards producing geology maps as GIS products, a conversion of the database and the CAD files to a GIS product is either done in-house, or the final product is GIS-importable. This involves extra time, patience and procedures to ensure a smooth transition of data into a GIS. To alleviate some of the added work, several agencies use GPS enabled handheld computers to enter data in a dBase-compatible format in the field, which is then downloaded and imported into a GIS in the field.
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During the summer of 2001, the bedrock mapping crew at Walmsley Lake first used Compaq iPaq Pocket PCs (PPC) to collect field data. Loaded with ArcPAD, an ESRI product, these PPCs enable the geologist to enter data (point, line or polygon) as ESRI shape files onto a map (hydrology, geology, etc.) or georeferenced image (magnetics, LandSAT, airphoto, etc.). These shape files are completely compatible with Arcview GIS 3.x and need only be downloaded from the PPC. Since that time, the NWT Geoscience Office (NTGO) has kept current with advancements in the system, which has evolved on both the software and hardware fronts.
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Initially, the ArcPad software used simple forms, built using Dialog Designer in ArcView 3.x, for data input. New software developments, such as the Application Builder, have improved the sophistication of the forms used for data collection. With this program, VBS code can now be integrated with the forms to perform data validation functions, as well as data entry time savers such as incrementing values, defaults and “remembering” the last value entered.
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Hardware improvements include faster processors, larger RAM capacities, and increased battery efficiencies, as well as the addition of Secure Digital (SD) and Compact Flash (CF) Card slots that now come standard on the PPC. These high-capacity memory cards can be loaded with several georeferenced image datasets (e.g., air photographs, regional magnetic data, satellite images, and existing geology maps), which are viewable within ArcPad. The addition of the memory card slots to the PPC has also dramatically increased the available accessories, such as a GPS, that can be added to the mapping tool. The PPC’s major limiting factor, however, remains the capability of the CPU. File size management and limiting the number of files open at one time in ArcPad alleviates the CPU limitations to a large degree.
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Advancements in humanware have also progressed to the point where user comfort with the PPC generates input such that customization of the ArcPAD base schema can be easily performed. The regular involvement of the user works as part of an iterative process meant to fine-tune the tool to suit each mapper’s specific project area and needs.
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The PPC has proven to be a durable and valuable regional mapping tool. In addition to data collection, it can serve as a navigational aid when linked to a GPS, and it allows access to a number of spatial datasets on the outcrop. Applications of the system are not limited to regional mapping. ArcPad and the PPC are particularly well tailored for the collection of point spatial data, and other obvious applications include stream sediment, soil, till, or rock sampling.
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To view the poster click on the image below.
(PDF Format 4.7MB)
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