Mapping formats - Automatic Vehicle Location
Map Formats and Information

• In order to represent the position of the Mobile Units accurately there are two possible solutions or kind of maps:

1. Raster Maps (scanned or image maps)

2. Vector Maps (digital or CAD maps)

Raster Maps

• Raster Maps are digital maps which are often obtained from seamless maps using a scanner or other peripheral, or on the other hand they can be produced directly from already-made vector maps or very accurate satellite imagery.

• Raster Maps are not very flexible, e.g. they don't allow editing or labeling without the aid of a graphic program or manual graphic edition. But they are easy to convert from printed maps and have the fastest redraw times if no software resize is used.

• The disadvantage of raster maps is the calibration and scanning process which may introduce errors if the seamless map is not scanned precisely. On the other hand they can be obtained with accurate satellite imagery where no calibration is needed, and it has many other advantages:

• They are able to show terrain features.

• Very good looking maps if the source is good.

• They are able to show street level detail too.

• Low-cost seamless maps are available.

XP-GPS AVL Software showing a Raster map with
roads, states, rivers and other features

• In order for obtain the best quality and redraw times, Raster Maps have to be resized at different scales. This process is not quite difficult but the total size of the map may be very huge, so this offers a limitation in the Raster Maps coverage to the amount of storage space available. And furthermore raster maps calibration is more often an art than a science. For these reasons Raster Maps are not preferred ones for AVL applications.

• HunterPro has developed its own raster map engine embedded in its CoyoteSP AVL software in order to obtain the fastest redraw times. We've calibrated many raster maps around the world which excellent precision. Many algorithms has been tested in special cases where maps were rotated, or present deformations. CoyoteSP AVL software can redraw raster maps with superior speed and quality than any vector map at the present.

Vector Maps

• Vector Maps consist of real databases with map information, street names, latitude and longitude coordinates of street intersections and many other information. They often present the exact location of special buildings or objects like schools, government buildings, fire hydrants, plazas, etc. The vector map engine present in CoyoteSP AVL software draws lines, arcs, and vectors based on the database.

• Special features – Vector Map Databases can include any kind of information, such as location of bus stops, traffic lights, pipes, gas lines, telephone poles, property boundaries, aqueducts, etc. This information can be edited, modified or deleted easily depending on the vector map format and application. Vector Maps may also include traffic attributes such as one way streets and turn restrictions at intersections which can be used to calculate routes and send out driving indications with speech like most commercial software does.

XP-GPS AVL Software showing Mexico country map and
the Caribbean. Street level detail available when you zoom in.

• Vector maps are powered by XP-GPS AVL Software, which is in partnership with the biggest GIS industry standard in vector maps and precision mapping for GPS and location based services.
  

• Zooming detail – When the user zoom out to cover a wide area of the map, only highways and major roads are shown so that the fastest redraw time can be achieved and minor details won't block the screen. As the user zoom in more streets are shown and more details are shown such as street name, zip code, etc.

• Seamless maps – Within Vector Map Databases, you can map a larger region without any visual seam. Integration of many different vector map is possible as the user may have different detailed maps together to cover the county plus a highway map of the entire nation. Its important to notice that the size of vector maps is very small compared with raster maps.

• Calibration – Because all vector maps are geo-referenced while editing, latitude and longitude information is available accurately so the software can use the GPS to identify which street is a vehicle on, which is the nearest cross street, etc. Geo-referenced vector maps doesn't require a calibration process as in raster maps.

• Find more information on HunterPro-GPS Products on these pages:
  
  Personal-GPS Page FOR PERSONAL LOCATION
  HunterPro-GPS Page FOR COMMERCIAL LOCATION
  

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