Address to Coordinate Conversion

[+Markwell]

Well, apparently, Mapblast hasn't seen fit to replace their display of coordinates on the map. As mentioned before, you can get the coordinates by going to their print screen.

 

Eagle Geocoding does show the results, as does Maporama.

 

Problem is, I'm getting widely varying results. Wider than if I took three separate readings from 3 GPSrs. I input my address into all three and the distances between them were very interesting:

 

Distance Geocode to Maporama: 58.87 feet

Distance Maporama to Mapblast: 427.99 feet

Distance Geocode to Mapblast: 402.38 feet

 

Distance GPS to Geocode: 177.28 feet

Distance GPS to Maporama: 214.59 feet

Distance GPS to Mapblast: 230.10 feet

 

My GPS location has been taken multiple days, with averaging on, etc. - so I'm most confident with that. But from the data above, it appears that Geocode is the closest to reality, with Maporama being next and Mapblast being the furthest from reality.

 

Any suggestions or comments? I'm looking for getting the best accuracy possible - at least within GPS tolerance.

 

Markwell

Chicago Geocachers

[+MrGigabyte]

I have found Maporama to be the most accurate around this area. Perhaps because they are french company they are partial to Canadians!

 

Anyway, it is my understanding that all of of the address to geographic conversions simply prorate the address range over the block distance. If the block happens to have lots all the same size, then the conversion will be quite good. If however, there is one large lot assigned to on address within an otherwise equidistant block, then all the addresses in that block will be out by a proportional amount based on their distance from that anonomly in the block address range.