THE LATITUDE AND LONGITUDE DATABASE

Latitude and longitude data found on this site have been provided by contributors to the Monroe County Historical and Genealogy website. The measurements have been made with hand-held GPS units. No claim is made for the quality of the data. Clearly, the precision of the data can be affected by the quality of the instrument used to measure it, as well as reading and recording errors, and such. The user of this data is cautioned to recognize that such problems can occur and to allow for some errors. Such errors not withstanding, latitude and longitude of specific sites measured by a GPS is likely to be infinitely more precise and useful for locating specific positions than alternatives, such as maps and directions.

Coordinate data will be added to the database as it becomes available. Anyone having coordinate data for specific sites is encouraged to submit it for inclusion on this web site. For the purpose of standardization, it is preferred that data be submitted electronically and that the format be the same as that which has been used in the web site database. Of course, if it is not in the optimum format, send it anyway -- we will be glad to receive whatever you have.

Latitude and Longitude (a refresher) Do you remember looking at a globe of the earth and seeing the lines that run from the north pole to the south pole. Those are lines or meridians of longitude. They are red in the sketch below. Then, recall the equator that runs around the earth dividing the northern hemisphere from the southern hemisphere. Also, recall the circles going around the earth as you go from the equator to the north or south pole. These are parallels or lines of latitude. They are blue in the picture below.

These lines are not actually on earth, of course, just on our globe. But, if they were painted on earth we would see and cross over red lines of longitude as we walked in an east-to-west or west-to-east direction. If we walked in a north-to-south or south-to-north direction we would see and cross over blue lines of latitude.

Imagine for a moment that the earth is painted with lines of latitude and longitude and that each line is given a number. Since we are working with circles (the globe) the numbers would be in degrees. Don t panic, we will not have to do any calculations with the degrees they are just used as the names or numbers of the lines of latitude and longitude.

Now since there are 360 degrees in a circle, if we painted lines of latitude or longitude at every single degree, there would be 360 lines of longitude painted on the earth with each of them starting at the north pole and running to the south pole (and vice versa). They would be the red lines in the sketch above. All 360 of these red lines of longitude would converge at both poles. At the equator, these lines of longitude would have their maximum separation from each other. In fact, at the equator, which is about 24,000 miles measured around the earth, the distance between each of the one-degree line of longitude and its neighbor would be about 66 English miles (meaning, a 5,280 foot mile like we use in England and America for measuring a mile). If we use nautical miles that equal 1.1 English miles, then the distance between one degree of longitude at the equator is exactly 60 nautical miles.

When the navigators and astronomers figure all this out a few hundred years ago, they decided that since the earth rotated 60 miles in each degree of rotation, they would subdivide each degree into 60 parts and call them minutes like the 60 minutes that we use to subdivide an hour of time. So in addition to having the earth divided into 360 degrees, each degree is further subdivided into 60 minutes. We can now paint (say, pink) lines of longitude between each neighboring red line of longitude. Now, as we walk from east-to-west (or vice versa) we will see 60 pink lines between each pair of red lines of longitude. At the equator, each pair of neighboring pink lines (that is, each minute of longitude) will be about 1.1 English miles or 1.0 nautical mile.

Let s stop there with our subdividing because for our purposes, degrees and minutes are all that is necessary.

You can paint the earth with blue lines of latitude in the same way that we did longitude. So, as you walk north and south (or vice versa) you come across (dark) blue lines of degrees of latitude and (light) blue lines of minutes of latitude.

You can now see that we have divided the earth into tiny blocks with our red, pink and blue lines of longitude and latitude. And, since each line has its own distinctive number, we can locate almost anything on earth by giving the number of the nearest lines.

This is a great system for locating things on earth and since these lines of latitude and longitude never changes, it provides a way of locating and communicating the location of whatever we like to other people including others who may be born, say, hundreds of years in the future.

Great, you say, but just how do we measure these latitudes and longitudes? The answer is, With a Global Positioning System (GPS).

What is a Global Positioning System (GPS) As some of us may remember and others may have studied in history, following WW II, there developed a major Cold War between the United States and Russia. The tension of that conflict became so serious that it appeared that a Hot War might develop. One of the weapons of choice for both sides in the conflict was the Intercontinental Ballistic Missile (ICBM). But to be able to use an ICBM effectively, a system was needed that could measure latitudes and longitudes with great precision. The answer to that requirement was the Global Positioning System (GPS).

The GPS that was developed consists of a large number of satellites that orbits the earth. These satellites are in what is called Polar Orbits meaning that their orbits take them over the north and south poles. The exact location of each satellite is precisely known at all times. Each satellite continuously transmits a radio signal back to earth. There are enough of these satellites in orbit that every spot on earth has at least 3 or more satellites overhead at all times. Because their orbits are so high, each satellite can see a large sector of the earth so the number of satellites can be kept to a reasonably small number.

By receiving signals from several (usually 3 to 5) satellites, it is possible to determine your position on earth with great accuracy (usually, within about 10 to 30 feet). This is done using a GPS unit. A GPS unit is about the size of a cell phone. It is similar to a radio direction finder in that it receives the transmissions from satellites overhead and through a process called triangulation calculates the precise location of the GPS unit. The results of this calculation are given directly in degrees and minutes (and decimals of minutes to the nearest one-thousandth of a minute).

Although the Cold War is over and the need for ICBMs has diminished, the GPS continues to provide a valuable service. It is used by navigators aboard ships, airplanes, and automobiles. It is also used by hikers and sportsmen. It continues to be used for military purposes such as precision targeting of missiles and smart bombs. And, it is also used by historians and genealogists for locating sites of villages, towns, buildings, cemeteries and graves that will ultimately vanish.

What is a Latitude and Longitude Database (L/L Database)? The Latitude and Longitude Database as used on this site is a collection of precise locations of possible future importance. An example is the measurement of the precise locations of cemeteries and grave sites that are at risk of being lost over the next few years or decades. The combination of efforts to inventory graves within each cemetery and the L/L Database will preserve the location of graves even if the visible cemetery markers are lost or removed.

For guidance on how you can use L/L data found on this site to locate specific places, click here.

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