The Maps web page allows you to view and edit the trees, furniture and site boundaries on the estate.

  • The normal web map controls are available to pan and zoom around the online maps and the maps/plans that you have loaded.
  • Each coloured icon on the map shows the location of a tree (circle), group of trees or hedge (polygon), or items of site furniture (squares, triangles, stars, lines and polygons).

Filter by Site and by Survey

The Site/Survey filter allows you to focus on what you want to view or edit. Only one set of survey data can be edited at a time, the rest are read-only.

  • Site Filter: The Site dropdown box at the top of the page allows you to view different parts of the estate.
    • The map will automatically zoom in to show the items on the selected site(s).
  • Survey Type: This dropdown box allows you to select which survey type to focus on, and which surveys are presented in the Survey box.
  • Survey Filter: The Survey dropdown changes which trees/item inspections are presented. Active/editable surveys are shown prefixed by a ‘*’.
    • The most recent inspection option shows all the items in the selected site(s) and the icons’ colour shows the most recently recorded data for “Condition”, Risk Category, etc. See the section on Map Colours below.
    • When a specific survey is selected, the icons’ colour shows the survey data as recorded in the selected survey. Items that were not part of the selected survey are shown as grey icons.
    • Over time, an estate will build up a history of survey data. Selecting each survey in turn will visually show how the condition of the items has changed over time.
  • Search by Reference. Type in the complete reference and press Search button. The map will zoom to the specified item.

Maps and Layers

The panels to the left of the map allow you to control how the data is shown on the map.

  • Select which base map you want to use.
    • Select one of the online world/aerial maps as a base, then you can overlay the user loaded maps on top of the selected base map. Note: there may be slight distortions on overlaid maps – see the Notes section below.
    • Select one of the estate’s maps as a base map.
    • If you have selected a Site (above) that is linked to a plan with no geo-spatial information, then you can only use that plan – not the online, world maps.
  • Show or hide user loaded maps.
  • If you have loaded your own geo-referenced Site Map into OTISS, then you have the option of viewing just your site map, or viewing your site map overlaid on top of the OpenStreetMap or Google base maps. You can also use a slider to make your site map partially transparent so that you can see both the base map and your site map. This makes it easier to plot items accurately by viewing two maps at once.
  • Show or hide the different types of surveyed items. This is useful when the maps gets very cluttered.

Map Icons

For each type of survey, there is a set of options to control the icons, labels and colours.

  • Show or hide the label showing the items’ reference.
  • Change the icon size.
    • Very Small, Small, Medium, Large, Very Large: These icons stay the same size at all zoom levels.
    • 1m Fixed, 2m Fixed, 5m Fixed: All items are drawn as a fixed ‘n’ metre icon. These icons get very small as you zoom out.
    • Actual Size: The icons are drawn at actual size as recorded in; the TreeSafety ‘CrownRadius’ field, the Furniture ‘width’ or ‘length’ field. These icons get very small as you zoom out.
    • For BS5837, the Actual Size option is a calculated average crown spread from the BS5837 north, south, east and west measurements. The OTISS map can only show the average crown spread, but the CAD/DXF download shows a more accurate drawing with the actual north, south, east and west measurements.
    • For BS5837, You also have the option of drawing the calculated RPA circle for trees (using the RPA radius calculations defined in the standard). RPAs are not drawn for trees of category ‘U’ (of course). For very small trees, we show a minimum of a 0.5m radius for the RPA – just so it is visible on the map. The RPA for groups, woodlands, etc. is the same polygon as you drew for the size/shape.
  • The colour of the map icons can be configured based on the values assigned to some of the survey fields – e.g. condition, life expectancy, risk category, customText, etc. The Icon Colours dropdown is used select which field to display. Use the Customise Survey buttons to set up the survey fields and configure which values are mapped to which colours. The BS5837 standard has defined the icon colours – so there is no configuration needed for the BS5837 icons.

Map tools

You must select a specific survey (in the survey filter at the top of the page) in order to edit the inspection data for that survey.  In addition, that survey must be in the Active state and the logged in user must be currently assigned to the survey.

When you have selected an Active survey (prefixed by a ‘*’ in the Survey box), the map tools allow you to create, edit, move and delete trees and items.

When a closed survey or the most recent inspection option is selected, you can view survey information but not change anything – the  Tool buttons will be greyed out.

To carry out an operation on a tree/item, first, click on a ‘tool’ button along the top of the map, then click on the icons to carry out the selected action.

  • New Tree/Item: Click at the required location on the map to create a new tree or item of furniture in the selected survey. You are then presented with the survey form where you enter a reference and the required data. Afterwards, you can then use the Move tool to re-position the icon.
  • New Group: Tree Groups are added by clicking the screen at the edges of the required shape, finish with a ‘double click’ on the last position – the survey form then appears for you to fill in the details. Each tree’s Structure field is used to choose the map representation – polygon for groups, hedges and woodland. Afterwards, you can use the Reshape and Move tools to re-draw the shape.
  • New Line/Polygon: Lines/polygons are added by clicking the screen at the edges of the required shape, finish with a ‘double click’ on the last position – the survey form then appears for you to fill in the details. Afterwards, you can use the Reshape and Move tools to re-draw the shape.
  • Replicate: Click on an existing icon/polygon, then click at the required location on the map to create a duplicate. If you click on a polygon/line, then you will be expected draw a new polygon/line for the replicated item. This action copies the survey data from the existing item to fill in the initial data for the new inspection.
    • When using the Replicate tool, all the fields in the new item (except the reference and location) are pre-populated with the values from the last item that you viewed or clicked.
    • This feature makes it much easier to create a new inspection that is similar to the last one. It is especially useful for creating avenues of similar trees.
  • Move: The move_feature_off symbol appears when you hover the mouse over any item, then you simply click and drag it to a new position. The position of the item that was recorded in any previous or ‘closed’ survey remains unchanged – this is to preserve the audit trail of the previous survey data.
  • Reshape lines and polygons:tree_group
    • When you click on a group of trees or polygon/line shape, pale blue circles appear at each vertex and on each line to show that it has become selected. The move_feature_off symbol appears when you hover the mouse over any of these circles. You can then click and drag each vertex to its new position. You can delete a vertex by pressing the delete button on the keyboard when the mouse is over the vertex (and the move_feature_off symbol is visible). The central pale blue circle can be used to drag the entire structure to a new location.
    • The position and shape of the item that was recorded in any previous inspections remains unchanged – this is to preserve the audit trail of the previous survey data.
  • Re-survey: Create a new inspection record for the selected item.
    • The map shows grey icons for items that have not yet been surveyed as part of the selected survey. You click on a grey icon to create a new inspection record for that tree/item. When you have finished, the icon will become coloured to show the Condition you have just recorded.
    • The initial values are copied from the selected icon – you should change these as required. In this case: the reference, species, etc. will (normally) remain unchanged  – its the same tree or bench!
    • The original inspection is unchanged and so an audit trail is maintained of inspections carried out for different surveys.
  • Edit: Edit the item’s inspection record.
    • This feature changes the data in the selected survey. This allows extra information to be added or existing values to be changed.
    • Note: there is no audit trail of these edits. The audit trail is kept for the different inspections carried out in different surveys (not within the same survey).
  • View: View the inspection record.
  • Delete: Delete the item.
    • A pop-up form asks you to confirm the deletion and to remind that this action cannot be undone.
    • If the deleted tree/item had no other inspections then it has been completely deleted.
    • If the deleted tree/item has another inspection in a different survey, then the icon will still appear on the map – but it will be coloured grey to show that it is not part of the selected survey.


  • 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. On the website we project the O.S. map as an overlay on top of the OSM/Google base map, so it appears slightly distorted at the edges. However, all our tree position data is stored as very accurate Long/Lat positions – so can be presented in any spatial map.

Any suggestions?

OTISS is constantly developing to suit our users’ requirements. Please contact us if you have suggestions for features or options that you would like to see.