1. aqui.io A coordinate shortening service Clodoveu Davis Departamento de Ciência da Computação Universidade Federal de Minas Gerais

2. We propose a practical method for encoding coordinates in short URLs, including support for any spatial reference system, with accuracy ranging from 10m to 1cm. Unlike URL shortening services, such as bit.ly and goo.gl, our method does not generate a hash code, but encodes the coordinates using a simple and fast algorithm. No precision is lost, and no permanent storage of codes is required. Any WGS84 coordinate can be encoded using 8 characters, while high-precision UTM coordinates take up to 14 characters. Applications aim at facilitating the integration of location data in social media and in volunteered geographic information applications.

3. http://aqui.io/hvVzTaRuXNG

4. Related: geohash Hierarchical encoding using base 32 – Each digit corresponds to a hierarchical level – Removing characters from the right side of the code reduces the precision – Codes do not necessarily correspond to the original coordinates

6. Proposal Convert coordinates into integers – Fixed decimal places Binary encoding using the smallest possible number of bits Alignment for base 64 (6-bit groups) Character encoding using a look-up table Lossless decoding: recovers exactly the input coordinates, within the precision option

7. Features Fixed number of decimal places Modes for lat/lon and UTM, any SRID Reserved mode for place names through a gazetteer link Precision: from 1cm to 10m

8. Example: lat/lon, WGS84, 10m precision = 4 decimal places WGS8410m Hemisphere (N/S, E/W) -22.7146-45.5934 pB0_HU6u 227146 455934 001111 011011 110100 111111 100001 101110 111010 010100 aqui.io/ 11

9. Features NOT hashing Does not require permanent storage of requested codes Small code that can be implemented in many languages and embedded in Web and mobile apps No Internet connection necessary to encode Precision selected according to the application

10. Modes SYS – Lat/lon WGS84 – Lat/lon any SRID – UTM PRECISION – 1cm (7 decimal places) – 10cm (6 decimal places) – 1m (5 decimal places) – 10m (4 decimal places)

11. Code length Mode /Precision WGS84 LatLon any SRID UTM 1cm--14 10cm (6 places)1113 1m (5 places)101211 10m (4 places)81110

12. Use case 1 -22.7146 -45.5934 aqui.io/pB0_HU6u OR

13. Use case 2 -22.7146 -45.5934 aqui.io/pB0_HU6u AND Orotour Garden Hotel

14. Use case 3 aqui.io/pB0_HU6u Brasil São Paulo Vale do Paraíba Campos do Jordão Orotour Garden Hotel Online Gazetteer Linked data

16. Use case 4 aqui.io/pB05bVb6 Campos do Jordão Online Gazetteer Linked data

17. Use case 5 @TransitoBH Congestionamento no Anel Rodoviário aqui.io/lqXaxdYOTG

18. Use case 6 VGI integration @VGI Public money wasted here! aqui.io/lqXaxdYOTG

19. Ongoing and future work Engineering – Design of tools, interfaces, libraries – Integration within mobile apps – Production site and services Research – Collecting and analyzing usage Expansion – Reverse geocoding integration – Place name mode (gazetteer)

21. aqui.io A coordinate shortening service clodoveu@dcc.ufmg.br