I have an .adf file that I have opened in R with the raster package. It's data on the saturation levels of Aragonite on a global scale. When I plot the raster it looks okay. But I need the data in lat/long! enter image description here

But when I examine the information the values for extent look more like UTM values and the coord ref says NA. class : RasterLayer dimensions : 64, 200, 12800 (nrow, ncol, ncell) resolution : 2e+05, 2e+05 (x, y) extent : -20037507, 19962493, -6363885, 6436115 (xmin, xmax, ymin, ymax) coord. ref. : NA data source : N:\My documents\Data\Exposure\Reefs at risk\Global_Threats\Acidification\arag_500\w001001.adf names : w001001 values : 0.7306441, 3.642071 (min, max)

I want to extract the points from this raster using the rastertopoints function but when I do I DO NOT get the UTM zone reference back so I cannot convert to lat/long.

I need the points in lat/long format in order to extract country names with the coordstocountries function and to overlay country boundaries with rworld maps.

Any help in coverting this raster to lat/long or converting the points without utm zones?

The prj.adf file associated with this .adf raster looks like this: Projection CYLINDRICAL Datum WGS84 Spheroid WGS84 Units METERS Zunits NO Xshift 0.0 Yshift 0.0 Parameters
1 /* Projection type < 1 | 2 | 3 > -160 0 0.0 /* Longitude of central meridian 0 0 0.0 /* Latitude of standard parallel

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    Lots of coordinates look like this (eg., albers), why do you think that it is UTM when the projection clearly states that it is CYLINDRICAL? You have the projection parameters. If they are not being read in the define them and then reproject the raster. How are your reading the raster? What does proj4string return? – Jeffrey Evans Dec 1 '16 at 17:36
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    The PROJ4 string will be +proj=cea +datum=wgs84 +lon_0=-160.0 +lat_ts=0.0 +x_0=0.0 +y_0=0.0 – mkennedy Dec 1 '16 at 18:15
  • I read in the raster using the raster function from the raster package. The proj4string() returns proj4string [1] NA. So I understand that it is not defined when I read it in with the raster package. The website this data comes from wri.org/resources/data-sets/reefs-risk-revisited says all data are 'Cylindrical Equal-Area (Lambert). Central Meridian: -160. Datum: WGS 1984.' It is WGS84 in meters projected to world cylindrical equal area. I would like to define the raster using the crs() function so I can then reproject it but I don't know the correct string. – Phoebe Stewart-Sinclair Dec 2 '16 at 10:30
  • mkennedy this returned an error "+proj=cea +datum=wgs84 +lon_0=-160.0 +lat_ts=0.0 +x_0=0.0 +y_0=0.0 is not a valid PROJ.4 CRS string" – Phoebe Stewart-Sinclair Dec 2 '16 at 12:49
  • Will you change the proj4 string slightly; wgs84 -> WGS84, in capital letters? – Kazuhito Dec 2 '16 at 23:05

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