encoding

[Alan]

I would like to ask for advice on encoding issues, and I apologize for
coming back to this list when I have asked questions about this in the
past.  I have gotten by for the most part, but every once in a while I
am bitten by an encoding issue.

By and large I have no need for multibyte encodings, but I do use
diacritic character modifications, and have an occasional need to use
greek characters, for example.  So I enabled UTF-8 encoding (without
really understanding the full extend of what is implied).

A the text output of a certain program includes the following.  I will
show it both as it appears in the terminal and as it appears in an
emacs buffer:

 - emacs:   19.6500° N, 156.0000° W

 - term:      19.6500° N, 156.0000° W

I am using emacs 23.1 (ubuntu intrepid ibex, emacs-snapshot).

The following is output from the command C-h C

-----------------------------
  U -- utf-8-unix (alias: mule-utf-8-unix)

Coding system for keyboard input:
  = -- no-conversion (alias: binary)

Coding system for terminal output:
  nil
Coding system for inter-client cut and paste:
  nil
Defaults for subprocess I/O:
  decoding: U -- utf-8-unix (alias: mule-utf-8-unix)

  encoding: U -- utf-8-unix (alias: mule-utf-8-unix)

---------------% end output--------------

The text in question is from subprocess I/O

The following are from my .emacs.el :

  (standard-display-8bit 160 255)
  (setq-default coding-system-for-write 'utf-8)

I have had trouble with text copied from a browser, which if I
remember correctly is why I implemented this default coding-system.

Can someone point the way to a simple explanation of the (seeming)
complexities of coding-systems for emacs?  Or suggest how I can set
this up?

Thank you

Alan