Merge pull request #92 from developmentseed/docs-88

Adding a bit more documentation around imagery sources

README.rst

@@ -25,6 +25,7 @@ For full documentation visit: http://landsat-util.readthedocs.org/
 
 To run the documentation locally::
 
+    $ pip install -r requirements/dev.txt
     $ cd docs
     $ make html
 
@@ -39,5 +40,3 @@ Change Log
 +++++++++
 
 See `CHANGES.txt <CHANGES.rst>`_.
-
-

docs/notes.rst

@@ -8,3 +8,5 @@ Important Notes
 - Image processing is a very heavy and resource consuming task. Each process takes about 5-10 mins. We recommend that you run the processes in smaller badges. Pansharpening, while increasing image resolution 2x, substantially increases processing time.
 
 - Landsat-util requires at least 2GB of Memory (RAM).
+
+- Make sure to read over the `section on returned products <overview.html#a-note-on-returned-products>`_ as it is different depending on scene acquisition date.

docs/overview.rst

@@ -80,3 +80,8 @@ Specify bands 3, 5 and 1::
 Process *and* pansharpen a downloaded image::
 
     $: landsat process path/to/LC80090452014008LGN00.tar.bz --pansharpen
+
+A note on returned products
+++++++++++++++++
+
+Scenes acquired after 2015 will be downloaded from `AWS Public Data Sets <http://aws.amazon.com/public-data-sets/landsat/>`_ while scenes acquired before 2015 will be downloaded from `Google Earth Engine <https://earthengine.google.org/>`_. AWS provides the bands separately and so landsat-util will also pass along the bands individually if requested. In the case of Google Earth Engine, only the full, compressed image bundle is available (including all bands and metadata) and will be downloaded no matter what bands are requested.