EPSG:4679 — Jouik 1961
Jouik 1961 (EPSG:4679) — a Geographic (degrees) system on the a=6378249.145 datum, used in Mauritania. Parameters, proj4, WKT, accuracy ±0.1 m, plus a free converter to…
At a glance
- EPSG
- 4679
- Name
- Jouik 1961
- Kind
- Geographic (degrees)
- Family
- Geographic (longitude/latitude)
- Ellipsoid
- a=6378249.145
- Accuracy
- ±0.1 m (vs PROJ)
- Countries
- Mauritania
Area of use
| West | -17.08° |
| South | 19.37° |
| East | -15.88° |
| North | 21.34° |
Projection parameters
| Projection | longlat |
| Semi-major axis | 6378249.145 |
| Inverse flattening | 293.465 |
| Helmert shift to WGS84 | -80.01,253.26,291.19,0,0,0,0 |
+proj=longlat +a=6378249.145 +rf=293.465 +no_defs +towgs84=-80.01,253.26,291.19,0,0,0,0
GEOGCS["GCS_Jouik 1961",DATUM["D_Custom_6378249.145",SPHEROID["Custom_6378249.145",6378249.145,293.465],TOWGS84[-80.01,253.26,291.19,0,0,0,0]],PRIMEM["Greenwich",0],UNIT["Degree",0.0174532925199433],AUTHORITY["EPSG","4679"]]
Sample conversion
Centre of the area of use: WGS84 -16.48000, 20.35500 → EPSG:4679 -16.4821085, 20.3541214
Values are within ±0.1 m at the test point.
About the Geographic (longitude/latitude) family
Jouik 1961 is a geographic coordinate system: positions are longitude and latitude in degrees on its reference ellipsoid, not metres on a plane. It is the datum layer that projected grids (UTM, national belts) are built upon.
Because it is unprojected, distances and areas cannot be measured directly from its degrees — convert to a metric projected system (or use a geodesic calculation) first. This page's converter does exactly that.
Related systems
- EPSG:3343 — Mauritania 1999 / UTM zone 28N
- EPSG:3344 — Mauritania 1999 / UTM zone 29N
- EPSG:3345 — Mauritania 1999 / UTM zone 30N
- EPSG:3367 — IGN Astro 1960 / UTM zone 28N
- EPSG:3368 — IGN Astro 1960 / UTM zone 29N
- EPSG:3369 — IGN Astro 1960 / UTM zone 30N
- EPSG:32628 — WGS 84 / UTM zone 28N
- EPSG:32629 — WGS 84 / UTM zone 29N
- EPSG:32630 — WGS 84 / UTM zone 30N
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FAQ
- What is EPSG:4679?
- It is the coordinate system “Jouik 1961”, a Geographic (degrees) system in the Geographic (longitude/latitude) family, identified worldwide by the code EPSG:4679.
- What datum does it use, and how accurate is it?
- It is based on the a=6378249.145 ellipsoid and it carries Helmert parameters to WGS84. The residual at the test point is about ±0.1 m versus PROJ; for centimetre work use a geodetic adjustment service.
- Where is this system used?
- It is used in Mauritania. This page shows its area of use as a coordinate rectangle above.
- How do I convert EPSG:4679 to WGS84?
- Use the free coordinate converter above (preloaded with this system) to convert to WGS84, UTM, or any other system, within a ±0.1 m residual.
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