EA Vertical Aerial Photography

< Back

Product Description:

Product Description:

Vertical aerial photography is an airborne mapping technique whereby an aircraft (fixed wing or rotary) is flown with a survey camera facing directly downwards underneath the aircraft.  The resultant photos capture sunlight reflected off the ground, measured in the red, green, blue, and near infrared portions of the electromagnetic spectrum.

The Environment Agency (EA) have been capturing vertical aerial photography since 2006, and have now collated an archive comprised of over 750 individual surveys which cover over 29,000 sq km in total (including some historic data where repeat surveys have been undertaken).  This archive has been categorised into a mixture of different imagery types, based on the following variations:

  • There are a range of different survey purposes:
    • By default, most surveys are undertaken in optimal lighting conditions during winter months (due to the reduction in vegetation); however
    • Incident Response (IR) surveys are undertaken at short notice in response to flooding events, and therefore can have a range of lighting conditions and may be processed to a lower visual aesthetic and spatial accuracy; and
    • Night Time surveys have occasionally been undertaken of urban environments, to survey the light emitted from street furniture
  • As technology has developed over the years, different survey cameras have been used:
    • Between 2006 and 2011, visible and near infrared surveys were undertaken separately as they used different equipment.  A modified Nikon camera was used to capture NIR imagery only.
    • In 2011, this was replaced with a Leica RCD30 camera, capable of capturing both visible and near infrared wavelengths simultaneously.  From this date combined raster datasets are available.

These variations have resulted in the following types of imagery being defined in the archive (the EA metadata catalogue contains full details), all of which are available to order through the Geospatial data service as separate layers:

Type/Layer

Description

Lighting Conditions

Years Flown

Raster Bands

Band1

Band2

Band3

Band4

RGB

Visible wavelength light producing ‘true colour’ imagery

Optimal

2006-2013

3-bands

Red

Green

Blue

NIR

Near infrared wavelength light (780-880nm)

Optimal

2008-2011

3-bands

NIR

NIR

NIR

RGBN

Both RGB and NIR captured simultaneously

Optimal

2011-2017

4-bands

Red

Green

Blue

NIR

Night Time

Bespoke camera settings used to enhance visible light emitted from street furniture

Night time

2009-2013

3-bands

Red

Green

Blue

IRRGB

RGB imagery but captured in Incident response conditions

Incident response

2006-2014

3-bands

Red

Green

Blue

IRNIR

NIR imagery but captured in Incident response conditions

Incident response

2009-2012

3-bands

NIR

NIR

NIR

IRRGBN

RGBN imagery but captured in Incident response conditions

Incident response

2013-2014

4-bands

Red

Green

Blue

NIR

The imagery has been captured at ground resolutions between 10cm and 1m, with the majority of surveys undertaken at 20cm.  It has been orthorectified to a high spatial horizontal (planar) accuracy using simultaneous LIDAR and GPS, and checked against OS MasterMap features.  Incident Response surveys may have a lower horizontal accuracy.

All imagery is supplied in multi-band raster format and OSGB36 projection.

Dataset Thumbnail:

 

Dataset Specification:

Product Name

Vertical Aerial Photography

Data Provider

 Environment Agency (EA)

Scale

Resolutions between 10cm – 1m (typically 20cm)

Coverage

Great Britain (partial)

Data Structure

Raster (8-bit, multi-band)

Format(s)

GeoTIFF

Uses

Licencing

OS OpenData Licence

Update Frequency

6 monthly (estimated)

 

Dataset Resources: