Consideration of Form Factor
By definition, GeoPad is form of rugged computer with an outdoor viewable screen. They are often equipped with wireless networking, a portable GPS receiver, digital camera, microphone-headset, voice-recognition software, GIS software, and supporting, digital, geo-referenced data-sets. However, the type of rugged computer needed to carry out your objective needs to be carefully considered. There are multiple form factors which can be used as GeoPads.
Rugged Tablet PC
A tablet PC is a culmination of advances in shrinking notebook hardware and improvements in integrated digitizers as methods of input. A digitizer is typically integrated with the screen, and correlates physical touch or digital pen interaction on the screen with the virtual information portrayed on it. A tablet's digitizer is an absolute pointing device rather than a relative pointing device like a mouse or touchpad. A target can be virtually interacted with directly at the point it appears on the screen. Rugged Tablets are equipped to withstand harsh outdoor conditions and to withstand wind, water and fine particles. Rugged Tablet PCs come in two flavors, slates and convertibles.
Slates, which resemble writing slates, are tablet PCs without a dedicated keyboard. Keyboards can usually be attached via a wireless or USB connection. Slate models are often designed with a focus on pure mobility, that is, the less to carry, the better.
Rugged tablet PC models are usually in the slate form factor, because without a keyboard, there are fewer moving parts to break.
Convertibles have a base body with an attached keyboard. They more closely resemble modern notebooks/laptops, and are usually heavier and larger than slates.
Typically, the base attaches to the display at on a rotating hinge. The hinge allows the screen to rotate around 180° and fold down on top of the keyboard to provide a flat writing surface. This design, although the most common, is a point of weakness on a convertible. A convertible design, the Panasonic Toughbook 19 is a fully ruggedized convertible.
Outdoor viewable displays are required on GeoPad devices. All outdoor viewable displays are not created equally. Take time to review current specs on displays and if possible "field" test the machine that you will buy.
Ultra Mobile PC
A recent addition to mainstream mobile computing, the Ultra-Mobile PCs have a 7-inch or smaller touch sensitive screen at a minimum resolution of 800 x 480. Windows XP Tablet PC Edition is used with slight tweaks to the interface to make it more suited for the small form factor. In addition, a software suite known as the Touch Pack Interface is included to make the interface more suitable for use of stylus as well as hand. UMPCs can be valuable for field based mapping and activities where weight is a consideration and maximum screen real estate is not necessary. Currently there are few rugged UMPCs on the market and they are quite expensive. This form factor is first to integrate a digital camera, GPS, Audio recording capabilities, wireless and bluetooth into one device.
PDA
Another field based option, a PDA or GeoPocket is easier to transport, requires less maintenance, and reduces overall costs compared to the GeoPad, however, those benefits come at the expense of what can be accomplished. Mapping exercises in particular are drastically affected by the reduction in screen real-estate, which supports an inadequate level of contextual information. The GeoPocket can be used effectively to support other field activities, however, such as data collection, stereonets, modeling, etc. PDAs run a limited version of windows which does not allow the full function of ArcGIS