Convert binary raster file to text CSV
Avoid using namespace std.
Assuming sizeof(int) is 4, the height array takes more than 40 MB of space. I understand that by modern standards it is a small change, but still a good citizen should not request more than is really needed.

I recommend a stream-like processing: read 2 bytes, convert them, and print out. This way you only need 2 bytes of storage.
The program terminates each row with a dangling comma. I don't know what the RFC says about it. Consider however

    for(int x = 0; x &lt; SRTM_SIZE; x++) {
        for(int y = 1; y &lt; SRTM_SIZE - 1; y++) {
            meinFile &lt;&lt; height[x][y] &lt;&lt; ",";
        }
        meinFile &lt;&lt; height[x][SRTM_SIZE - 1] &lt;&lt; std::endl;
    }

You test reading errors. Writing may also fail.
Error detection is important. Error reporting is equally important.

Can't open file - why? Is it insufficient permission? file not found? corrupted media?

Can't read file - why? Can't write file - why?

Check out strerror, perror or similar facilities.