Survey Maps

From the list of Downloaded Surveys, you can select a survey and choose the Start Survey option. You are presented with a map of the site showing the items that have already been created.

On the OTISS website you can upload your own maps and plans and assign them to the survey sites. Your maps/plans can then be used on the mobile survey apps when you download/sync the survey.

The map is automatically zoomed to include the survey items on the site. If there are no existing items; you can pan and zoom to the required site, or turn on the Location featurewhich will automatically centre the map at your current location. When you have a break, and then restart a survey; we remember the last item that you surveyed and zoom the map to that location.


Coloured Icons – Tree Survey and Asset Survey

  • The survey items appear on the map as coloured icons with their reference number. The icon size and label position are configured in the Settings.
  • Amber coloured icons, lines and polygons represent trees/items that have been previously surveyed, but have not yet been inspected as part of this survey.
  • Green coloured icons, lines and polygons represent items that have already been surveyed as part of this survey.
  • If you downloaded both a Tree Safety survey and a Furniture survey for the same site, then both sets of icons will be displayed on the map at the same time.
  • Icons are coloured blue when being moved or when re-shaping a line/polygon.

Coloured Icons – BS5837 SurveyBS5837 map key

  • The survey items appear on the map as coloured circles and polygons with their reference number. The icon size and label position are configured in the Settings.
  • The icon colours corresponds to the BS5837 Retention Category.
  • Icons are coloured blue when being moved or when re-shaping a polygon.

Tools Menu/Bar 

The Tool Menu/Bar provides a set of tools to allow you to navigate around the map; and to add and survey items. The blue coloured icon at the top of the screen shows the currently selected tool. Pressing on this blue icon shows the menu of tools available, just touch the one you want and it appears at the top of the screen.  One of the options is to swap to use the Tool Bar.

The Tool Bar shows all the same tools as a second line of icons at the top of the screen. They are always visible and the currently selected tool is coloured blue. The Tool Bar should make it easier to swap between tools when adding, moving and re-shaping.  The X icon on the right closes the Tool Bar and reverts to the Tool Menu.

The Tool Menu and Bar have the same tools and you can change between them to suit your screen size. Typically the Tool Menu is better on smaller screens, whereas the Tool Bar is easier on larger screens. There is also a Settings option to select the size of the tool icons.

Tools – Pan/Zoom Map

Pan and zoom around the map using touch controls and buttons.  In fact you can pan and zoom around the map in any of these Tool modes, but when in the Pan/Zoom mode, touching an item does not show the inspection form or move it’s position – making it easier to scroll around the map when there are lots of items.

Tools – Add

When the Add tools are selected, new items can be added to the survey by tapping on the screen at the required location.

Single trees and items are added by selecting the Add Tree/Item tool and simply touching the screen at the required location.  If you have turned on the Location feature, then simply tap on the red cross-hairs (+) to position the tree at your current position. The survey form then appears for you to fill in the details.

Tree Groups or lines/polygons are added by selecting the Add Group/Line/Polygon tool and then touching the screen at the edges of the required shape, finish with a quick ‘double tap’ on the last position – the survey form then appears for you to fill in the details. We have found that a stylus is better than your fingers when drawing shapes. At any time you can touch the Tool icon again to clear the partially draw shape and start again.

The items can be re-positioned and re-shaped later using the Move and Re-Shape tools described below.

Tools – Replicate last item

When the Replicate tool is selected, tap on the map to replicate the last item that was added or edited. All the fields in the new item are pre-populated with the values from the previous item, and the reference/tag field is automatically filled in with the next tag number. This makes it easy to create a row of similar items. If the last item was a group/polygon, you will be expected to draw a new polygon (finish with a quick ‘double tap’ on the last position).

Tools – Edit/View

When the Edit tool is selected, items can be surveyed (or resurveyed) by tapping on the icon. This brings up the survey form where you can change the survey data. Changing the tree’s TreeStructure field will change the map representation, then you can use the Move tool or the Re-shape tool to draw the shapes you require.

Tools – Moving items

When the Move tool is selected, items can be dragged to new positions. In this mode, all the items are coloured blue to show that they can be moved.  Simply touch and drag the item to its new position.

Tools – Re-shape items

The Re-shape tool is used to re-shape the polygons that represent groups of trees and hedges. When you tap on a polygon, pale blue circles appear at each vertex and on each line to show that it has become selected. Simply touch and drag each vertex to its new position. The central pale blue circle can be used to drag the entire structure to a new location. We have found that a stylus is better than your fingers when drawing shapes.

Tools – Photos

This will first save an changes you have made and then take you to the Photos page so that you can look at all the existing photos for this tree/item and take new ones.


Layers Menu

The Layers menu is used to select the map base layer you wish to use and to show/hide the survey layers. If you have loaded your own geo-referenced map into OTISS, then you have the option of viewing just your site map, or viewing your map overlaid on top of another base map. Note: some distortion can appear around the edges of your map if it has to be transformed to a different map projection. The survey icons can be shown/hidden to have a clearer view of the map.

Location Icon

Press the location icon (top right on the screen) to turn the track my location feature on/off. When the location feature is turned on, the device’s GPS (or an external Bluetooth GPS) are used to centre the map at the current location. A red cross indicates the reported GPS position, and a red circle gives a rough idea of the ‘accuracy’. As you walk around the site, the map will automatically follow you, making it easy to plot and inspect the nearby trees and items. On larger screens, the current grid reference is shown on the top bar.

When using the Add Tree/Item tool, touching the red cross will automatically plot the tree/item at the current GPS position (i.e. at the centre of the cross).
If you need to plot a tree ‘near’ to the red cross (but not at the GPS position), then (a) tap the Location icon to turn off the GPS feature, (b) plot the tree at the required location, and (c) tap the Location icon again to restart the GPS

Note: constantly using the GPS requires more power and will use up your battery quicker. Getting the best out of your GPS…

Redraw Map Icon

Occasionally, the map displays pink squares when it cannot immediately find the correct map tiles to display – whether from ‘online’ maps or the downloaded ‘offline’ maps. This may only be a temporary issue, or may be because you have lost contact with the OTISS, OpenStreetMap or Google map servers. In any case, pressing the Redraw Map icon will redraw the map again, and hopefully fill in the missing map tiles.


Settings Icon

The font size used on the forms and menus can be adjusted.

The icon size can be adjusted.

The label position can be adjusted.

The map co-ordinate system can be selected position can be adjusted, e.g. GB Ordnance survey, Irish ITM, or Longitude/Latitude.

Turn the Auto Offline Maps on and off. You can also delete the offline map tiles for all surveys.



  • The Google RoadMap and Aerial views do seem have a time lag when you zoom in/out. The drawings seem to lag behind for a second, and then slide into place. This does not happen on OpenStreetMap or your uploaded PDFs/maps or any others we have tried – just the Google ones! This is something to do with the Google maps – over which we have no control.
  • The OpenStreetMap and the Google maps are all on the same spatial projection. So (apart from the time lag), positions and shares should appear exactly the same.
  • The UK Ordnance Survey use a different spatial projection, so when you upload an O.S. map. you can get slight distortions. For example, if you use the app to draw a perfect square on an O.S. base map, and then change to the OSM/Google base map, the square appears to be slightly distorted. However, all our tree position data is stored as very accurate Long/Lat positions – so can be presented in any spatial map.