Prospect overview Download Getting started Context data Species codes

Context

A project in Prospect displays your woodland in its context. To represent the context, as a minimum, you need data that describes the shape of the terrain. In addition there are optional themes that you can choose to apply. Some of these may be specific to one project, while others will potentially be applicable to all of your projects. The “Context” panel on the “Map” page lets you specify what data you want to use.

Data shared by all projects

3D terrain data

50m gridded terrain data

To use Prospect you must have a set of tiles describing a Digital Terrain Model (DTM) on a 50 metre grid. The tiles you have should cover an area significantly larger than your project area since Prospect will use this data to display the background view of distant mountains. The maximum distance used is 30km. You can choose to install just the tiles that you need (in Map Maker TER format or ESRI ASC format) but since the data is not that large the easiest option is to install the dataset for the entire UK (excluding Northern Ireland).

 

This can be downloaded from http://mapmaker.com/GB/gbTerrain.zip . This zip file contains the data in Map Maker TER format. Unzip the data then select the directory where the files are in the “Context” settings.

 

Alternatively, this can be downloaded for free from the Ordnance Survey: http://Ordnancesurvey.co.uk/opendatadownload/products.html

 

The data comes in the form of a zip file, “Terr50_gagg_gb.zip” containing ESRI ASC files. Select this file and Prospect will unzip the contained ASC files and then convert them into the TER format used by Prospect.

 

If you need data for Northern Ireland then it can be downloaded for free from: http://mapmaker.com/downloads/NI_ter.zip

 

This zip file contains TER files, so you should unzip the file and then in Prospect select the directory containing the TER files.

5m gridded terrain data

Some users like using higher resolution terrain data. 5m DTMs are commercially available and can be used to portray foreground terrain in combination with the 50m data for the more distant areas. But, bear in mind that 5m data consumes 100 times more memory than 50m data and will slow down the redrawing process. Also, we have found that some 5m data contains discontinuities so our personal view is that it is best avoided, but it is a matter of preference.

Raster layers

A raster layer consists of a directory of calibrated bitmap images. Prospect distinguishes between aerial photography and other raster tiles.

Aerial photography

If you have access to aerial photography in ECW format then ensure that all of the tiles are in a single directory and then select that directory.

Raster tiles

Any type of raster tile can be used in TIF, JPG, or BMP format. The tiles should be calibrated in one of three ways: a) using “world” files (i.e. TFW, JGW, or BPW files), b) using Map maker calibration, or c) using the Ordnance Survey naming convention, e.g. NR8056.tif.

 

Tiles can be purchased from a commercial supplier or you can download free tiles based on Ordnance Survey Open Data from: http://mapmaker.com/GB/overview.htm

 

For Northern Ireland free tiles based on the Ordnance Survey of Northern Ireland data can be downloaded from http://mapmaker.com/downloads/NI_tif.zip

 

This zip file contains TIF files, so you should unzip the file and then in Prospect select the directory containing the TIF files.

Forestry Commission data

The Forestry Commission produces a variety of datasets that can be used for free. These can be found at: http://Data-forestry.opendata.arcgis.com

 

Prospect can make use of two of these datasets:

National Forest Inventory

The National Forest inventory shows all of the woodland in Great Britain as a set of polygons. The polygons are classified by broad categories such as conifer, broadleaf, mixed-mainly conifer, etc. There is not data about species, height, or age but it makes a valuable addition to the context and we recommend that you make use of it.

 

Note that on the Forestry Commission web site you can download the entire data for the Great Britain but if your projects are confined to England, say, then it is best to just download the data for England since that will take less memory.

National Forest Estate Roads

The data showing the whereabouts of Forestry Commission tracks is useful for making the maps and views in prospect more intelligible.

Bodies of water

Using the terrain model and aerial photography it can sometimes be difficult to see lakes and water courses. The Ordnance Survey Open Map data includes data on water so we have extracted this and put it into separate files. The data for Great Britain can be freely downloaded from: http://mapmaker.com/GB/water.zip . You should unzip the DRA files contained into a single directory and then in prospect select that directory.

Altitude colours

If you have no aerial photography and no raster tiles the three-dimensionality of the images can still be enhanced by using colours to represent altitude. In the dialogue box you can click on different altitude bands to specify a corresponding colour.

 

Even where you are using aerial photography and/or raster tiles the altitude colours can still be helpful.

 

The “Context” panel contains slider controls that allow you to adjust the opacity of the various data sets. This can be useful to create mixes, such as raster tiles laid over aerial photographt, and also to limit the intensity of the background – for instance full colour rendering of aerial photography can easily distract from the woodlands that you really want to be focusing on.

 

Remember, that if you make use of any of the context layers which are based on Ordnance Survey Open Data then any images which you produce using Prospect must include the Ordnance Survey copyright statement, see “ OS Open Data Acknowledgements ”.

Context layers specific to this project

The layers specific to the project contain everything else other than the woodland itself. There are various types of layer available:

Woodland layer

This should not be confused with the project woodland – this type of woodland layer contains data about surrounding areas of woodland which may be more detailed and up-to-date than that in the National Forest Inventory. You can choose either a Map Maker DRA file or an ESRI SHP file containing polygons. The file should include an attribute column containing species codes. Optionally there can be an attribute column containing height data. If this is omitted then a default height of 6 metres is applied to all species.

Water features

You can choose either a Map Maker DRA file or an ESRI SHP file containing lines and/or polygons. You can specify a line width. This layer will be drawn in blue.

Roads

You can choose either a Map Maker DRA file or an ESRI SHP file containing lines. You can specify a line width, colour, and one of three double-line types. The settings are applied to all of the roads in the layer.

Other linear features

You can choose either a Map Maker DRA file or an ESRI SHP file containing lines. You can specify a line width, colour, and one of four line types. The settings are applied to all of the lines in the layer.

Symbols

You can choose either a Map Maker DRA file or an ESRI SHP file containing points. You can specify a symbol size, colour, and one of four symbol types. The settings are applied to all of the points in the layer.

Wind farm

You can choose either a Map Maker DRA file or an ESRI SHP file containing points. Each point is taken to reprent the location of a wind turbine. You can specify the overall height of the turbine (i.e. tower height + turbine radius), the radius of the “apron”, i.e. the open space around the foot of each turbine, and the wind direction. The settings are applied to all of the points in the layer.

Raster image

You can choose a BMP, TIF, JPG, or ECW file to add as a layer. Typically you might do this where you did not have comprehensive aerial photography for the region but you did have one calibrated aerial image covering the local area. Or you might have a scan of an existing paper map of an estate. You can specify the opacity of the image.

3D surface

You can choose a Map Maker TER file or an ESRI ASC file containing a Digital Terrain Model. Typically you might do this where you were using the 50m DTM for the general landscape but you had bought a tile of 5m DTM for your local area. Where a 3D surface layered is applied the values in the layer will be sued in preference to those in the general landscape layer. However, care should be taken since where the edge of the 5m data occurs and the 50m data resumes there will inevitably be discontinuities which can look conspicuous in a view.


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