Release 0.6 August 31st 2014.
This is a major release of Bunjil Forest Watch.
Although still just a prototype, much of the core functionality is now present. Still missing is the ability to make and send reports on forest disturbances.
There has been a major overhaul of the maps and images overlays into a framework or layers that you can control with opacity sliders and hide check box.
If you get stuck, please understand it is still a prototype and log an issue.Chris Goodman, August 2014
Check for New Images
Areas with one or more followers are now checked for new images are every night. The admin user can also kick of the job with /admin/checknew or /admin/checknew/area_name
If a newer image is found, Bunjil creates a new Observation Task and composes an email containing a message and a link to the task. AppEngine sends the email to the first follower of an area when there is a new image to review.
Each Observation Tasks has:
- The ID of the new LANDSAT image,
- The name of the area being monitored
- The owner of the task (a follower of the area)
A user opens a task by clicking on the link in the email. So far, the only other method is to enter the url directly as obs//. Admin can look up the task_key in the Datastore.
When a task is first opened in a browser the application contacts Google Earth Engine to create an RGB (or visual) overlay showing the latest satellite image(s).
An overlay is also created to show the land just prior to the latest observation. The prior overlay shows the most recent cloud-free pixel before the latest image. This overlay is merge of several older images.
Bunjil displays the Latest overlays on the left map, and the Prior overlays on the right map.
If a user moves the left map, the right map will also move to the same view. An Expand button allows the user to hide the right map and grow the left map to the entire window.
Once Earth Engine has calculated an overlay, Bunjil stores a reference to it as a tiled map object so the overlay need not be recalculated when the user refreshes or returns to the page or another user opens the task. Earth Engine retains the overlay as a set of google map tiles for a day or so. When the map tiles get deleted and returns a HTTP 404, Bunjil will automatically ask earth engine to generate a new overlay map .
When Bunjil is creating an overlay, it displays a new job in the ‘Updates’ panel. These jobs refer to requests sent between servers and should last less than a minute. When complete the result of the job is either an error message or a new overlay. The user may delete these messages.
The user can generate Ad-Hoc overlays by setting the RGB, Latest and Collection drop downs and clicking the View button. These are not stored in the database of overlays. Choose either the latest, or earlier Landsat images from either Landsat-8 or Landsat-7. NDVI is not yet working, so only RGB images are present.
All overlays have a transparency slider and a hide check box. This includes the area boundary and the Landsat grid.
The Landsat grid and area boundary are also treated as overlays that the user can hide or make more transparent.
The Landsat Grid is shown in New Area, View Area and View Observation.
For New Area it is passive overlay that just shows where the image boundaries are. As the area boundaries are not yet known, all cells within the view radius are included.
For View Area, it is an active overlay that you can click to select which cells to monitor.
For View Observation the grid behaves the same as View Area, but will be made passive so only the owner can select cells to monitor.
We have updated the New Area interaction in this Release. The map opens on the region where the user’s browser is located.
There is now a Search box for finding specific areas by name.
There is more form checking before submit – leading to a more reliable operation and better user experience.
Areas and the Area description can now support non-ascii names with different alphabets.
After creating a new area, Bunjil takes the user to the View Area interaction. This shows the overlapping Landsat Cells (identified with a path and a row). Bunjil asks the user to select the cells that are relevant for future monitoring. Clicking on cells makes their outline bold to show they are monitored. Clicking again reverses the process.
Bunjil won’t create an observation task for an area unless two things are true: the area’s owner has selected at least one cell for monitoring and the area has at least one follower. Then when the scheduled Check New job runs and there are new images for those selected cells, Bunjil sends an email to the follower from email@example.com.
The area’s creator does not get these emails as they cannot yet follow their own area.
The authentication has been improved so that user’s are redirectred to their original resource (such as an observation link) after they authenticated.
Before logging in, users see an improved ‘home’ page – but it still needs a lot more improving… It currently shows a map of forest change created by researchers using Earth Engine and a video. Plans for it to have a tutorial on Bunjil to make the site self-explanatory are still a bit off.
Please log in with a google (gmail) account. Admin will only see your email address, and the areas and reports you create in Bunjil, never your password or other data.