Geocode IQ®

Our geocode directories are updated quarterly from industry-leading geocode data providers.

Firstlogic’s and SAP’s Geocoding Transform converts physical addresses into latitude and longitude coordinates using the “Interpolated Geocoding” algorithm. We use data from the TIGER/Line® geographic coding system.

TIGER/Line system maps a location’s street segment to a geographic coordinate space which includes a range of house numbers. Interpolated geocoding matches an address to a street segment and then computes the likely position of the address.

Suppose a street segment in a city block includes house numbers ranging from 100 to 200, for example. The database knows the coordinates for the beginning and end of the segment and evenly assigns the coordinates for the locations between them. Address-level geocoding routines assume house number 150 to be in the middle of the coordinate range while it assigns a house number of 190 coordinates near the end of the street segment. If the houses are not equally spaced along the street, the assigned coordinates could be off by a small amount. For most commercial purposes, this level of accuracy is acceptable.

Address-Level geocoding may be very accurate within cities with short, regular street blocks, but the system accuracy decreases as population density declines.

Parcel-Level geocoding converts physical land parcels into latitude and longitude coordinates using geographic cadastral data where there are no overlapping parcels or gaps in land lots. When you perform geocoding with parcel-level data, the latitude and longitude of a location is determined by the center of a land parcel.

Parcel-level geocoding works extremely well in rural or undeveloped areas lacking the structure of street grids and city blocks. Depending on the application, an organization may choose to use parcel-level geocoding methods in an urban setting as well, as it can sometimes return more precise locations.