Frequently Asked Questions


1. What is the accuracy of the parcel data?  The accuracy of the property lines varies depending on different factors.  In general the newer a subdivision, the more accurate the mapped lines.  In a newer subdivision, past 5 years or so, the lines are probably within 5 feet +/- of where they actually exist.  In an older, more rural portion of the county, the property lines may not have been surveyed in many years.  Those lines could have been mapped according to fence lines or other various assumed physical representations of where the property lines were thought to exist.  Typically today we rely on deeds and plats of record to map the property lines.  In areas of concern, these records are checked to re-map areas that appear to be inconsistent.  The property lines are certainly not survey accurate and are not intended to represent actual surveyed property lines.

2. What is the difference between an address point address and a parcel address? Address points represent the general location of a unique address – for example an individual house, apartment, condominium or office. Parcel addresses are specific to a piece of real estate.

3. What is the difference between oblique photography & aerial/ ortho photography? Oblique photography is taken at an angle, similar to what you might see looking out the window of an airplane, while traditional aerial photography is taken looking straight down while directly over the area being photographed.

4. How does the 911 service know where I am? If you are calling on a land line, the service address of the phone you are calling on is used. In the case of a cell phone, the location is determined using GPS if your phone has this capability, or by triangulating your location using all the cell towers that can pick up the signal from your phone.

5. What is the difference between GIS and GPS? A GIS, or Geographic Information System, is a computer system that keeps and uses maps in a digital form. GPS, or Global Positioning System, is a service that uses satellites and a special receiver to find your location based on the signals received from the satellites. GPS data is frequently added to, or used with, a GIS to create new data or to find data in a GIS.

6. Why not just use Google Maps? Google Maps is a good tool for getting directions from one location to another or for creating an overall view of an area. However, Google data can change frequently and only at the discretion of Google. No background information about the data source is provided, it is unknown whether the photos are ortho-corrected, and is often flown during the summer when trees are covered with leaves. This is a problem because in order to use the photos in a GIS, the ground beneath trees must be visible. This is why LINK-GIS has its photography flown in early spring, before trees begin budding. Also, the data is often copyrighted, raising legal issues and possible restrictions on its use.

7. What is the accuracy of the aerials/ Ortho Photography? Our aerial photography is re-flown every 3-4 years resulting in ortho-photography with a resolution of 6 inches on the ground. This means an object in the photo would have to be about 9-12 inches across in order to show up at this level of detail.

8. Where does the GIS data come from?  The basemap data, which includes roads, buildings, streams, etc., is obtained from aerial photography. Other data like city boundaries or property lines are gathered from legal descriptions.

9. What is Envista? Have you ever seen a newly paved road torn up to repair some problem, and then, a month later, torn up again in the same spot by a different agency to fix another problem? Well, Envista is a system which allows utility companies, the Kentucky Transportation Cabinet, and county and city public works departments to share information about their work schedules and locations. The system finds where these schedules and locations overlap and then notifies these organizations so that they can potentially coordinate their work and save time, money and aggravation while keeping the road in good repair. It has already saved significant sums of money for participants in the short time it has been available.