diff --git a/README.md b/README.md index a9ff8fb4..fd04ac55 100644 --- a/README.md +++ b/README.md @@ -27,7 +27,7 @@ Algorithms to * shorten them relative to a reference location, and * recover a location from a short code and a reference location given as latitude/longitude pair -are publicly available and can be used without restriction. Geocoding services are not a part of the Open Location Code technology. +Are publicly available and can be used without restriction. Geocoding services are not a part of the Open Location Code technology. Links ----- @@ -41,8 +41,8 @@ Description Codes are made up of a sequence of digits chosen from a set of 20. The digits in the code alternate between latitude and longitude. The first -four digits describe a one degree latitude by one degree longitude -area, aligned on degrees. Adding two further digits to the code, +four digits describe a one-degree latitude by one-degree longitude +area, aligned on degrees. Adding two further digits to the code reduces the area to 1/20th of a degree by 1/20th of a degree within the previous area. And so on - each pair of digits reduces the area to 1/400th of the previous area. @@ -54,10 +54,10 @@ by 14 meter wide area within 6GCR. A "+" character is used after eight digits, to break the code up into two parts and to distinguish codes from postal codes. -There will be locations where a 10-digit code is not sufficiently precise, but +There will be locations where a 10-digit code is not sufficiently precise. However, refining it by a factor of 20 is i) unnecessarily precise and ii) requires extending the code by two digits. Instead, after 10 digits, the area is divided -into a 4x5 grid and a single digit used to identify the grid square. A single +into a 4x5 grid, and a single digit is used to identify the grid square. A single grid refinement step reduces the area to approximately 3.5x2.8 meters. Codes can be shortened relative to a location. This reduces the number of digits @@ -69,9 +69,9 @@ code can be shortened depends on the proximity of the reference location. If the reference location is derived from a town or city name, it is dependent on the accuracy of the geocoding service. Although one service may place "Zurich" close to the Google office, another may move it by a hundred meters or -more, and this could be enough to prevent the original code being recovered. +more, and this could be enough to prevent the original code from being recovered. Rather than a large city size feature to generate the reference location, it is -better to use smaller, neighbourhood features, that will not have as much +better to use smaller, neighborhood features, that will not have as much variation in their geocode results. Guidelines for shortening codes are in the [wiki](Documentation/Specification/Short_Code_Guidance.md). @@ -96,6 +96,6 @@ languages. Each implementation provides the following functions: * Encode a latitude and longitude to a standard accuracy (14 meter by 14 meter) code * Encode a latitude and longitude to a code of any length - * Decode a code to its coordinates: low, high and center + * Decode a code to its coordinates: low, high, and center * Shorten a full code relative to a location * Extend a short code relative to a location