1

I am new in the field and I would like to ask which is the correct way to define a point location for an image with EPSG 4326 crs.

I used QGIS software, and created a .csv file with the latitude - longitude information in decimal degrees (I was given the information of those coordinates both in Degrees - Minutes - Seconds, and decimal degrees. I checked these from Google Maps to see if they represent my locations of interest.) I added this .csv file I created as "delimited text layer" in QGIS to define the points in QGIS. And I used these points to extract remote sensing data from the image.

My question is; is defining the points in decimal degrees is correct for EPSG 4326 crs images?

1

Yes, it is. EPSG 4326 is the identifier for the World Geodetic System 84 (WGS84). If you check the Well Known Text (WKT) for WGS84 you will see it uses degrees as units:

GEOGCS["WGS 84",
    DATUM["WGS_1984",
        SPHEROID["WGS 84",6378137,298.257223563,
            AUTHORITY["EPSG","7030"]],
        AUTHORITY["EPSG","6326"]],
    PRIMEM["Greenwich",0,
        AUTHORITY["EPSG","8901"]],
    UNIT["degree",0.01745329251994328,
        AUTHORITY["EPSG","9122"]],
    AUTHORITY["EPSG","4326"]]

Furthermore, if you check its bounds, you will see it goes from -180 to 180 (longitude) and from -90 to 90 (latitude).

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.