User Guide

Sun and Shade Analyzer (SASHA) User Guide

First use

To run SASHA, find the SASHA icon on your home screen, and press it.


The first time you run SASHA, you are presented with a six screen mini-tutorial.  Each screen allows you to navigate forward to the next screen, backward to the prior screen, or to cancel out of the tutorial.  The purpose of the tutorial:

  1. Welcome  you;
  2. Inform you that you will have to grant permissions;
  3. Let you know that it will take a moment to find your location before the app gets under way;
  4. Describe SASHA’s augmented reality indicators and how to aim the camera;
  5. Tell you how to initiate a capture
  6. Tell you to repeat steps 4-5 until everything is captured;
  7. Ask you to wait for the result to display;
  8. Tell you how to get the mini-tutorial again at any time;
  9. Introduce you to the main pull-down menu.

Grant Permissions

After the mini-tutorial, you are shown a screen explaining the permissions SASHA requires you to grant.  Hit “OK”.

Next, Android will request permission 3 times; respond with OK each time.

Determine Location

Then you will get a dialog box asking  you to wait while SASHA determines you location.  Depending on the strength of the GPS signals, this could take 10-30 seconds, or even more.

Augmented Reality Capture Screen

After a few seconds, you will be presented a description of the Augmented Reality screen which will appear next.  Hit “Dismiss”.

The Augmented Reality Capture Screen will appear.

From this point on, follow the instructions starting at xxx in the next section.

Regular Scan (not initial)

Determine Location

Then you will get a dialog box asking  you to wait while SASHA determines you location.  Depending on the strength of the GPS signals, this could take 10-30 seconds, or even more. If SASHA seems to get stuck determining your location, make sure you have turned on Android’s location service.

Augmented Reality Capture Screen

You are not present with the “Preview screen”, which is very similar to the preview screen of your camera app, except that 1) it also shows where the sun could be during your chosen date range, 2) it allows you to take a picture; and 3) allows you to select options by means of the options menu.

  1. Possible sun locations: During the chosen date interval, the sun travels across the sky, rising in the East and setting in the West, but along a slightly different path each day. The paths are higher in the summer and lower in the winter. SASHA draws a red outline around the entire region where the sun could appear; the sun will never appear outside the red outline during the date interval that has been selected. This outlined region is subdivided into small “tiles” with gray edges. The outline is an “augmented reality markup” of your surroundings. As you move your camera, the red lines will stay lined up with objects in your surroundings (because the sun’s paths are part of your surroundings), rather than stay fixed on your screen.
  2. Capture: Your job is to “capture” (or photograph) the everything inside the red outline (i.e. all the places the sun could appear).
    1. You point the camera so that a goodly portion of the outline is visible in the screen, and touch anywhere on the screen to do a capture. When you do that, tiles which are entirely on-screen will turn gray, to show you that they have been captured.
    2. Now you aim the camera to capture some more tiles which have not turned gray yet, and touch the screen again, to make them become gray.
    3. You continue in this vein until all of the tiles have been captured, i.e. turned gray. The lower right hand corner of the screen show a counter showing how many tiles there are and how many have been captured,
    4. When all tiles have been captured, the preview screen will close, and computation progress dialog will launch.
    5. If you think that you have captured all the tiles, but the computation dialog has not launched a) check the counters; b) look along the edges, along the red outline, for tiles that are not captured. Especially on the horizontal ends of the red outline.
  3. Option Menu: The upper right hand corner of the screen has an options menu (3 vertical dots). This allows you to:
    1. Set custom Date Range: Set the date interval, specified by a “From” date and a “To” date. This date interval is the period of time over which daily hours of direct sunlight are averaged. The date interval typically should correspond to your growing season, i.e. when your plants need sun to grow. By default, SASHA sets the date interval to start on the earliest date in the spring after which there is less than 10% chance of frost, and to end on the latest date in the fall before which there is less than 10% chance of frost.
      However, you can choose any other pair of dates (From, To) – they must be at least one day apart, but no more than 365 days apart, and must both be in the same year.
    2. Show Angles: The right hand side of the display (black background) will display the Azimuth, Elevation of the lens axis, and the tilt of the camera from horizontal. A cross-hair will show in the center of the screen, indicating the direction where the lens axis points.
    3. Enable Foliage Simulation: If one were to take measurements with SASHA during the winter, the readings you get would not match the readings you would get during the summer, because the tree’s leaves have fallen and do not block the light when SASHA examines the sky, However, it is often desirable to measure summertime sunshine during the late winter or early spring when it is best to plant many species. In order to address this situation, SASHA supports “foliage simulation”, which detects tiles with a lot of branches in them, and evaluates the entire tile as if it were all leaves.
    4. Clear Preferences: Some user settings can persist across SASHA sessions, e.g. custom date range. This option forces those settings back to their default values.
    5. About SASHA: shows SASHA’s version, build and the Camera API version.
    6. Developer Options: Allows one to send a SASHA log to the developer. It may also allow certain debugging options to be turned on (usually disabled).
  4. Help Menu: Indicated by a “?”, the help menu offers help.

To be continuded….