There are two main models for storing and representing spatial data in a Geographic Information System (GIS): the raster the vector models:

Raster Data – raster (or grid cell type) data can be used for analyzing, overlaying, and modelling area features such as soil types or forested areas. Raster data are generally typically scanned in from maps.
Vector Data – vector data can be used to represent linear features such as roads, streams or area edges and can be combined with raster data for display purposes or for analysis.
In general, Raster maps are faster, Vector maps are more specific and more accurate.

SHAPEFILE

Shapefile is an open, widely used format developed by ESRI in which spatial data are represented in layers.

It includes:
• Geometry files
• Attributes files
• Index files

It is easy to integrate in specific application environment thanks to its layered data model and to its standard GIS format; so, it is easy to:
• Integrate in commercial GIS software
• Implement as geo-objects in a RDBMS with spatial functions

RASTER MAPS

Digital photo base maps, scanned paper maps, and other raster maps are very effective base layers for internet map servers or standalone desktop analysis systems. To overlay “vector” map layers on top of “raster” maps, the raster maps must be georeferenced. Aerial or satellite photo maps should also be orthorectified: i.e. processed to remove distortions due to terrain and camera optics.

Georeferencing means that the TIF, SID, JPG or other raster image file must have a companion file containing the map projection and the UTM, Latitude-longitude, or other real-world coordinates that correspond to specific pixel coordinates in the image. The digital photo maps and other raster maps are always shipped with georeferencing information in the form of a MapInfo *.TAB, ESRI *.tfw, or equivalent file.

High Resolution Satellites
• IKONOS II
• EROS A
• QuickBird
• SPOT 5

They are able to acquire images in panchromatic and multi-spettral way (except for EROS A) with a high resolution (near photographic resolution) and with precision characteristics compatible with medium and big scale cartography (1:25000 – 1:5000).

IKONOS
The Ikonos-2 satellite was launched in September 1999 and has been delivering commercial data since early 2000. Ikonos is the first of the next generation of high spatial resolution satellites. Ikonos data records 4 channels of multispectral data at 4 metre resolution and one panchromatic channel with 1 metre resolution. This means that Ikonos was the first commercial satellite to deliver near photographic high resolution satellite imagery of anywhere in the world. Data is 80% cloud free.

Radiometric Resolution: Ikonos data is collected as 11 bits per pixel (2048 gray tones). This means that there is more definition in the grey scale values and as a viewer you can see more detail in an image. In order to benefit from this additional information, you will need specialist image processing software.
Ikonos has both cross and along track viewing instruments which enable flexible data acquisitions and frequent revisiting capabilities – 3 days at 1 metre resolution and 1 to 2 days at 1.5 metre resolution.

Vectorial Maps

Digital Vector products are representations of major topographic map features with attributed point, line and region/area data.

TeleAtlas
TeleAtlas MultiNet data, is a fully attributed and multi-layered vector dataset containing detailed street networks, water features, parks and landmarks, county, city and civil divisions, ZIP codes, urbanized area codes and census tracts. This data can be formatted for MapInfo or ArcView and projected to align with your existing data. Tele Atlas data contains detailed routing attributes such as street directions.

Key Benefits
• Accurately understand geographic relationships and solve geographic business problems
• Improve location-based analysis
• Incorporate dynamic data, such as real-time traffic reports, easily
• Build powerful, robust digital mapping applications quickly
• Simplify your geocoding process and receive up to 99.8% match rates
• Includes ramps, overpasses, underpasses and highway interchanges
• Use a single source for highly accurate, nationwide route planning and spatial queries
• Superior geocoding for linking with other geographically linkable data
• Route planning attributes for pathfinding and distribution planning applications
• Convenient formats for easy integration with your existing systems
Note: Data is available by County, State or user-defined area.

Layers: Street Network, RailRoads, Point of Interest, Boundaries – City, State, Municipal, Hydrography.
Most map data vendors, including Tele Atlas, obtain their raw data from government resources. What happens with that data afterwards, however, is what differentiates one vendor from the rest. Tele Atlas geo-referencing technologists apply state-of-the-art processes using commercial and proprietary aerial imagery and reposition millions of road segments to better match their real-world geographic locations.
Various product formats:
• Shapefile
• Oracle Spatial
• GDF-AR
• GDF-AS

Geografic (vectorial) database realizing detailed and complete sets of informations on:
• Transportation Networks
• Waterways
• Land use and land cover
• Other various information layers

Covered areas:
• Western Europe
• North America

Other characteristics:
• object-oriented approach to geografic data description
• Support for TMC Database to georeference traffic jam information

NavTeq
NAVTEQ now offers digital map coverage in 48 countries on four continents.

NAVTEQ maps provide a highly accurate representation of the detailed road network including up to 160 attributes like turn restrictions, physical barriers and gates, one-way streets, restricted access and relative road heights.

NAVTEQ digital map data offers accuracy, detail, reliability, and flexibility. Continuously updated to maintain its freshness and precision, NAVTEQ digital map data not only enables door-to-door routing throughout Europe and North America, it contains millions of Points of Interest (POIs), making it easy to locate everything from restaurants to hospitals and gas stations. You’ll find NAVTEQ data onboard most navigation-enabled vehicles produced in North America and Europe and on all the top Internet navigation sites. It is the unseen force behind the leading express mail services, emergency and government routing plans, efficient field service management, as well as numerous fleet operations, worldwide. Plus, it is the foundation for a growing category of wireless, Location Based Services (LBS).

Five hundred NAVTEQ field researchers from approximately 125 offices drive millions of meters of the road network each year.

Teams of field researchers fan out across the globe each day, continually driving and redriving the roads, using proprietary digital data collection tools to ensure NAVTEQ digital map data more closely reflects real world conditions.

NAVTEQ POIs are gathered from multiple resources to create one of the richest collections available. NAVTEQ POIs are derived through NAVTEQ field team on-site collection, multiple third-party business listings and specialty source data.

NAVTEQ POIs are quality checked using a variety of tools including in-field, remote and automated quality checking.

NAVTEQ already supports traffic-enabled systems throughout Europe.

Supported product formats:
1 ArcView Shapefile, ArcInfo, MapInfo and Oracle formats are formatted to work with third party tools. The tool applications provide APIs that work with the NAVTEQ map data. We recommend investigating third party tools to determine if they meet your needs. The download grid offers some insight.
2 GDF and SIF+ formats are ASCII representations of our NAVTEQ map data. Processing is necessary to use GDF and SIF+ formats in an application environment. The raw data needs to be compiled in a format that can be used efficiently. The software will also need to be written to access the data. The software will extract data for map rendering, route calculation, point of interest look-up, etc.