Tracking a plot
Content
This article discusses the following topics:
Important concepts to know; polygons, markers and more
Different ways to track a plot
Auto-tracking a polygon
Manual tracking a polygon
Pausing your collection
Plot validity
Plot quality
Editing a polygon
Recollecting a polygon
Important concepts to know; polygons, markers and more
Before diving into the how-to's of data collection it is important to have a solid basis of many of the underlying concepts.
The term Polygon has been used greedily in this manual, it refers of course to the shape of a plot traced by the app. When you are mapping a plot you are essentially creating a polygon.
A polygon is created by putting down coordinates which the app connects with lines. Each coordinate is called a marker. These can be put down manually or automatic.
Submission or sometimes known as synching refers to the sending of the profile to the local partner. Once this is done no data can be edited.
GPS accuracy is the extent to which your location coordinates (and thus markers) are correctly identified. Due to varies reasons (e.g. mountains and phone type) your location might not be accurate.
Different ways to track a plot
When it comes to tracking the polygon, there are different ways to put down markers. These can be used interchangeably. At any point during collection, there is the possibility to switch these options.
Auto-tracking - automatic tracking, as the name indicates, puts down markers automatically. This enables you as data collector to start collection, put the phone in your bag and focus on the walking of the plot. This is especially useful in challenging environments like rocky terrains or cold weather.
Manual tracking - refers to tracking a plot by manually putting down every marker. In some cases, when there is a hindrance on the road of a stream of water, you might need to take a long detour. To avoid having to edit longer then necessary, you can use manual-tracking and chose when to place, and not place, a marker.
Auto-tracking a polygon
How to use auto-tracking:
The map will automatically zoom into your current location.
Ensure auto-track is enabled.
Check the accuracy (it should be below 10m)
Hold the blue button to start tracking.
You can start moving when the app says ‘Tracking’…
Manual tracking a polygon
To plot manually:
The map will automatically zoom into your current location.
Disable auto-track.
To drop a point, hold the blue button.
Walk and hold the blue button to drop another point. Make sure to add as many markers as possible to prevent having to recollect this plot.
To finish a polygon, click on the green button.
Done!
Pausing your collection
It may happen that you'd like to pause collection. This can be a tactic for collecting where you may need to cross a part that does not need collecting, or to visit another app (e.g. google maps or WhatsApp). Always pause collection when doing other activities (e.g. taking phone calls) on your device or data may be lost.
Plot validity
After collection it mag happen that your polygon shows invalid. There are three reasons this may happen:
The plot is too small - if the plot is smaller than 0.1ha the plot will show invalid. This is due to measurements not being accurate with this size. These can not be onboarded onto the program.
Intersecting lines - it may happen that the plot intersects with itself. This is often due to GPS inaccuracies. This must be fixed before submission.
Plot overlap - there are multiple reasons that a plot may overlap:
Small overlap with neighbouring plot due to GPS inaccuracy etc. - this can be edited before submission.
Large overlap due to unclarity of farm ownership - plot overlap is not blocking for submission, this is because the local partner might need to make a decision regarding land tenure. Submit the profile and inform your local partner of why your plot may be correct.
Plot quality
Plot validity does not necessarily mean that a plot has good quality. Plot quality is influenced by many factors including type of tracking and farm location.
"A high quality plot accurately resembles the farm"
Things to look out for when collecting a plot:
High GPS accuracy
Full area of farm plotted - measurements are only done on the polygon, this means that it the polygon is smaller or larger than needed, wrong measurements can be made.
No unnecessary buildings - plots should not contain buildings, if there are buildings in the middle of a farm, that is not a problem. If they are on the boundary, do not take them into the collection area.
Editing a polygon
In case of small errors, a plot can be edited within the app. Watch the video to find out how or follow the steps below.
Video:
Editing a plot has the following functionalities:
Adding markers - with this you can add markers between the one you are placed on and the one prior. This can be useful when dealing with shapely farms, which requires the plot to have many bends.
Deleting markers - GPS inaccuracy might create intersecting lines. In cases like these you can delete markers to fix any validity issues.
Moving markers - be it due to overlap. GPS inaccuracy or any other amount of issues. Moving markers ensures you can create the highest quality polygon.
To edit a polygon:
1. Click the "Edit Plot" button.
2. Use the green button to move / add or remove individual markers. The arrows allow you to navigate between the different markers that have been collected.
Recollecting a polygon
If there is an issue with a profile - it may be sent back to your device. They will be shown under the "In progress" tab. If you've received a profile that you haven't collected ask your local partner what actions might be appropriate for that recollection.
