Preparing your data for ArcPad

ArcPad is a mapping tool for working with your GIS data in the field. Field GIS tasks are often quite different from the GIS tasks performed in the office, and so are the computers used in these different environments. Desktop computers usually have fast CPUs, large amounts of RAM and disk space, and large display monitors. In contrast, field computers have relatively slow CPUs and limited RAM and storage capacity. Furthermore, the field work environment ranges from working in bright sunlight to rain to sub-zero snow conditions, compared to the constant temperature and lighting conditions of the office environment. Consequently, you need to consider all of these factors before preparing your GIS data for use in the field with ArcPad.

Answers to the following questions determine how you need to prepare your data for optimum use in the field:

• What tasks will be performed in the field and what data will be needed for these tasks?
• What data will be updated and what data will be needed for background reference?
• What is an appropriate amount of data, taking into account the field tasks as well as the field computer’s CPU, RAM, and storage capacity?
• What symbology needs to be used for effectively displaying the data on the field computer in the expected weather and lighting conditions?

This is an important issue. The artificial light and large monitors used in the office environment enable the use of a wide range of colors and symbols, whereas only a limited number of colors and symbols provide sufficient contrast when used in the field with small computer screens and strong sunlight.

Although ArcPad supports most of the symbology available with ArcGIS, it may not always be appropriate for field conditions to use the complex symbology supported by ArcGIS and ArcPad. In many cases basic, high-contrast symbols using primary colors are more effective in the field than detailed symbols using a wide spectrum of colors.

There are a number of different operations that you may need to perform to prepare your data for use in the field with ArcPad, including:

• Extracting an appropriate subset of the data
• Converting the data into a format supported by ArcPad
• Projecting the data into a projection supported by ArcPad
• Specifying symbology that has sufficient contrast for the expected field lighting conditions
• Preparing data input forms and validation rules to ensure that data is captured accurately in the field

The ArcPad Data Manager for ArcGIS provides some of the tools to prepare data for use with ArcPad. Additional tools for tasks, such as projecting data, are included with ArcGIS Desktop.

In summary, it is essential to always bear in mind that field computers, tasks, and conditions are very different to computers, tasks, and conditions in the office. Therefore, what works in the office environment may often not be effective in a field environment.

Data not supported by the ArcPad Data Manager

The following data types are not currently supported by the ArcPad Data Manager:

• Geometric Networks—You can check out the feature classes that participate in a geometric network; however, the network is not supported in ArcPad.
• Feature class to feature class relationships
• Table to table, and table to feature class relationships
• ArcGIS annotation layers are not supported in ArcPad; however, map annotation is supported in ArcPad 10.0.2 and above.
• Image Services
• SDE spatial views—Partial views can be copied out and viewed in ArcPad, but just as edits cannot be made to spatial views in ArcMap, edits from ArcPad cannot be checked in. Alternatively, use definition queries on feature layers to achieve a similar layer representation in ArcMap, which in turn, can be checked out to ArcPad.
• Attachments—Feature classes that have been enabled for attachments can still be checked out to ArcPad but attachments cannot be added in ArcPad. You will see the attachment table appear as a related table in ArcPad and ArcPad Studio, but it only lists the descriptive fields and does not include the attachment. You can still edit the feature class and any other related table records, and check these edits back into your geodatabase.
• Vendor specific geometry—ArcPad supports the SDE binary data type directly and does not support the ST_Geometry data type (or any other vendor specific spatial data type).

  If the columns STArea() and STLength() are exposed in your geodatabase in ArcMap, the Data Manager automatically hides these columns upon check out, and therefore they are ignored by ArcPad. When you check in your data, the contents of these columns are calculated by ArcMap.

  If any other vendor specific geometry columns are exposed in your geodatabase, manually hide these fields in ArcMap before attempting to check out data for ArcPad.