Understanding mapping

From Active911 Documentation Wiki
Revision as of 17:17, 14 November 2019 by Wyattg (Talk | contribs)

(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to: navigation, search

Introduction

By default, when we get an alert from your dispatch, we attempt to generate a latitude and longitude for the alert location by searching Google Maps for the address your dispatch provided us. These are the steps we follow:

  1. We check the call data sent by your dispatch for an address.
    If no address is given, we skip mapping completely.
    We check for a city name.
    If your dispatch specifies a city, we will use it. If not, we check to see if you have set a default city. If you haven't, we will usually default to the name of your county. If we don't have that, either, we will use the city from your account address.
    We check for a state.
    If no state is given, we use the one from your account address.
    We search Google Maps for "ADDRESS CITY, STATE".
    Remember, if you didn't give us a city, this will usually be "ADDRESS, COUNTY, STATE".
    We make sure the result is reasonable.
    This means calculating the distance as the crow flies between your main address and the one that Google returns in the search. If the distance is more than 20 miles, we discard it and skip mapping. We can adjust the distance used to discard mapping that is too far away at request of the agency's admin.
    We replace the city name with the one that came up in the Google search.
    This is only done if your dispatch did not specify a city and we were forced to use a guess.


How to get the best mapping results with Active911

GPS coordinates from dispatch

Most CAD systems used by dispatch centers only send Active911 the street address and city name for the location of a call. Some CAD systems are capable of sending the GPS coordinates for the location of a call, in addition to sending the street address. Using GPS coordinates sent by dispatch for mapping in Active911 is the best way to get accurate mapping, ASLONG AS THE COORDINATES PROVIDED BY DISPATCH ARE ACCURATE. If your dispatch is sending us GPS coordinates, click here for more information about how tell Active911 to use the coordinates for mapping.

Wiz

Wiz is a mapping system that was built by Active911 to use GIS shapefiles provided by users to improve mapping accuracy. If your department has a GIS shapefile that contains address points for the addresses in your jurisdiction, you can send that file to Active911 to use with Wiz and improve the mapping accuracy of your alerts. For more details about how Wiz works, and what is required to use it, please click here.

Related FAQ

The mapping for my alert took me to the wrong location

This is one of the most common problems users experience. There are many things that could contribute to mapping/routing inaccuracies. The only way to determine the root problem, and potentially fix it, is to report the issue directly to our support team (click here for contact information). Provide the following information to our support team for an alert that mapped/routed you incorrectly:

  1. The Active911 number for the alert. It can be found in the alert details screen for each individual alert.
  2. The full street address and city name for the location you should have been mapped/routed to.
Why did I not see a map?
Usually, no map either means your dispatch didn't specify an address, or the address they sent us didn't map (came up more than 20 miles away).
An intersection did not map properly!
Try searching maps.google.com for "INTERSECTION OF a AND b". If it does not map, you may need to report the problem to Google. If the roads do not intersect (an overpass, for example) try searching for "HIGHWAY a AT b". If it maps OK, but we did something wrong, please let us know.
A mile marker did not map!
Google does not recognize mile markers as addresses, and can't provide routing to them. Try dispatching the location as an intersection or an address, and put the mile marker in the details.
A railroad crossing did not map!
Google does not recognize railroad crossings as addresses, and can't provide routing to them. Try dispatching the location as an intersection or an address, and put the mile marker in the details.
What can I do to improve mapping?
Check with your dispatch to see if they can send us the GPS coordinates (latitude and longitude in decimal degrees) for the locations of your calls.
Make sure your dispatch is sending us a city name!
Get setup to use our "Wiz" mapping system.
Let us know when something isn't right. Please report incorrect mapping to support.