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Geographic Coordinate System Guidelines

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Geographic Coordinate System Guidelines JULY 2, 2019 Geographic Coordinate System Guidelines 4C Services GmbH Hohenzollernring 72, 50672 Köln, Germany Tel. +49-221-50802050 www.4C-Services.org 1. Background To obtain a 4C certificate and to start the audit process, 4C Services requires the provision of explicit geographic coordinates of the producers and service providers of a 4C Unit within the template of the Business Partner Map (BPM). The requirement is to provide the coordinates in a specific geographic format, the decimal degree. This document provides a guideline to identify if the coordinates are given in the correct format and how to conduct a fast reasonability test for the given coordinates. 2. Overview of different formats of geographic coordinates A geographic coordinate system is a coordinate system that enables every location on Earth to be specified by a set of numbers, letters or symbols. All coordinate systems and formats have in common that the location is specified with an x- and a y-value. There are several possibilities how the coordinate could look like in different systems and formats: Required standard for 4C Alternative formats, that are not accepted by 4C Another type of decimal Degree, Minutes, Decimal degree coordinate UTM Coordinate Place degree coordinate Seconds/DMS coordinate (Latitude, Longitude) (projected coordinate) (Latitude, Longitude) (Latitude, Longitude) Cologne 50.935055°, 6.963833° 50.935055° N, 6.963833° E 50° 56' 06.2" N, 6° 57' 49.8" E 356929.8, 5644577.1 Bogotá 4.710989°, -74.072092° 4.710989° N, 74.072092° W 4° 42' 39.6" N, 74° 04' 19.5" W 397089.1, 520786.2 Remarks Latitude: Latitude Latitude Note Value between -90° and 90° N = North, S = South N = North, S = South In this case, the coordinate is transformed Minus indicate position in Longitude Longitude into a two-dimensional Southern Hemisphere E = East, W = West E = East, W = West metric system. A Longitude: commonly used metric Note Note system is e.g. UTM. Value between -180° and 180° In this format, the indication In this format, the coordinate is Without knowing which Minus indicate position in of southern or western not given in a decimal value, but metric system has been Western Hemisphere hemisphere is not indicated in Degrees, Minutes and used, the exact location by a – (Minus), but by the Seconds. The coordinates can cannot be indicated with Note letters S or W be transformed into the required this format and therefore The ° (degree sign) is optional decimal degree format (see cannot be accepted by 4C useful websites below) 1 3. Typical mistakes that can be identified by a fast scroll through the coordinates in the BPM Examples Notes Cologne Bogotá (Latitude, Longitude) (Latitude, Longitude) Correct format in decimal degree The latitude value is between -90 and 90 50.935055, 6.963833 4.710989, -74.072092 The longitude value is between -180 and 180 Also correct in decimal degree The latitude value is between -90 and 90 50.935055°, 6.963833° 4.710989°, -74.072092° The longitude value is between -180 and 180 Problem: Values are not between -90 and 90, or 180 and -180, respectively Possible explanations: 50.935055, 696.3833 4710989, -74072092 a) Typo, comma at wrong position or forgotten c) wrong coordinate system (e.g. UTM) b) Wrong coordinate Problem: Positive values, even if the region of the 4C unit is on the southern or western hemisphere 50.935055, 6.963833 4.710989, 74.072092 Possible explanations: a) Typo, minus missing b) Wrong coordinate 2 4. How to conduct a fast reasonability test with the coordinates After the verification that the coordinates are given in the correct format, a fast reasonability test with a small sample size of the coordinates can reveal if the locations are at least in the correct region. The region should be indicated in the BPM. Step 1: Go to GoogleMaps (or equivalent website) and navigate to the country/region, where the 4C unit is located. Get an overview where the country / region is located. Location Notes Region is in the southern hemisphere Latitude-value should be negative Region is in the western hemisphere Longitude-value should be negative Step 2: Click into the map to read out the coordinates (see chapter 5 for examples). Question Notes The given coordinate within a region should fit roughly to coordinates Which coordinate is displayed? Does it fit roughly to the from the BPM. Tip: Use the BPM information to find out, where the coordinates given in the BPM? coordinates should be located (e.g. Municipality) and then navigate to that region in the map Step 3: Type in a random sample coordinate of the BPM into the search-box of GoogleMaps (latitude, longitude) and observe where you are navigated to. Question Notes YES: Everything is fine. Repeat the test with some other randomly chosen points, especially if the 4C Unit is spread among different regions/municipalities NO: If you end up in the ocean, a different country or even a different Do you end up in the respective region of the point (e.g. continent, it can have the following reasons: according to the Municipality mentioned in the BPM)? a) Longitude and latitude are transposed b) The minus (-) for the hemisphere indication is missing c) The given coordinates are wrong 3 5. Examples from Google Maps a) Cologne Latitude 50.9412830 Positive value means in Northern Hemisphere Longitude 6.9582700 Positive value means in Eastern Hemisphere b) Argentina Latitude -34.6207000 Negative value means in Southern Hemisphere Longitude -58.3705870 Negative value means in Western Hemisphere 4 6. Background Information: Latitude and Longitude Coordinate in the Geographic Coordinate System image source: http://eogn.com/images/newsletter/2014/Latitude-and-longitude.png Latitude Longitude Lines measured in north-south position between the poles Lines of longitude/meridian measured east-west position Equator is defined as 0° Prime meridian of 0° runs through Greenwich, England Northern Hemisphere: Eastern Hemisphere: 0 until +90 0 until +180 Southern Hemisphere: Western Hemisphere: 0 until -90 0 until -180 image source: https://wiki--travel.com/img/flat-map-of-the-world-with-longitude-and-latitude-2.html 5 a. Two common formats of Latitude and Longitude Coordinate: 1) DDD° MM' SS.S" : Degrees, Minutes and Seconds 4° 42' 39.6" N 74° 04' 19.5" W Most common format used to mark maps 2) DDD.DDDDD° : Decimal Degrees 4.710989° N 74.072092° W or +4.710989, -74.072092 Most common format in most computer-based mapping system displaying (e.g.: Google Map, Google Earth) b. Coordinate Conversion 15” = 0.25’ Symbol Definition: 30” = 0.5’ 0 : Degrees 45” = 0.75’ ‘ : Minutes 60” = 1’ “ : Seconds 60’ = 1° + Northern Hemisphere or Eastern Hemisphere - Southern Hemisphere or Western Hemisphere c. Conversion Tools Conversion among different geographic coordinate systems is made necessary by the different geographic coordinate systems in use across the world and over time. Below are several useful links for conversion between latitude longitude coordinate and projected coordinate . http://www.rcn.montana.edu/resources/converter.aspx . http://www.synnatschke.de/geo-tools/coordinate-converter.php . https://www.latlong.net/lat-long-utm.html . https://www.latlong.net/lat-long-dms.html . http://www.earthpoint.us/Convert.aspx . http://www.zonums.com/online/coords/cotrans.php?module=1 . https://www.geoplaner.com 6.
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