Aerodrome Surveys and Software

WGS-84 Aerodrome Surveys

Formed in 1987 to provide a high quality Land and Building Surveying service to the design sectors of the construction industry, SLC Geomatic Solutions now offer a full range of surveying and mapping services.

In 1995, the then GPS department completed the first successful British WGS-84 Implementation and Aerodrome Facilities Survey at Jersey Airport.

Since then they have utilised their skills in geodetic surveying to assist more than 95 UK licensed airports comply with ICAO directives on the use of WGS-84 as common datum for air navigation.

Internationally, SLC Geomatic Solutions assists IATA and ICAO with their GNSS Implementation Schemes which, combined with other overseas work, has resulted in successful WGS-84 Airfield Surveys at a further 92 airports overseas including the airports in Anguilla, Bahrain, British Virgin Islands, Cape Verde, Kenya, Kosovo, Mauritius, Montserrat, Nigeria, Oman, Qatar, Seychelles, Turks and Caicos Islands, the UAE and Venezuela.

For the last three years, the specialists at SLC Geomatic Solutions have been working closely with industry partners to devise a method that could be rolled out as an industry wide solution for eTOD (ICAO Annex 15, Chapter 10).

The final solution needed to, and does, meet the following criteria:

• Does not interfere with the operations of the ATC
• Combines both the terrain and obstacle survey in one single operation
• Can be utilised anywhere in the world regardless of local hazards or dangers
• Capable of meeting the higher accuracy requirements of other ICAO documents (Annex 14, Annex 4, Doc 9674, etc
• Economically acceptable

eTOD Software

Much more than just a data store, GDMS is a bespoke Geospatial Information System with a suite of tools for handling electronic terrain and obstacle data (eTOD) and carrying out obstruction analysis against Obstacle Limitation Surfaces (Safeguarding).

GDMS enables you to maximise the benefits from your investment. With GDMS you can use eTOD for 3D presentations, aerodrome safeguarding and management of airport development.

In common with all Geographical Information Systems, GDMS can interact with a powerful database and create a views of the environment by creating multiple layers of information such as raster and vector mapping, aerial and satellite images, 3d terrain data (eTOD), airports obstacle limitation surfaces (Annex 14, Navigation Aids, etc) and User created zones. However, unlike most GIS, GDMS can also view the data in 3 dimensions with the images draped onto the terrain data and can carry out real-time fly through simulation.

One major difference between GDMS and other commercial GIS is that integrated into the system is the Aerodrome Safeguarding Toolkit (AST-Pro), which carries out the automated modeling of obstacle limitation surfaces and the analysis of obstructions. This module can automatically create the complete Annex 14 (or CAP168) 3d model by simply inputting the aerodrome data.

The resulting 3 dimensional model is available for use in any Workspace by simple selecting it from the Database Manager, furthermore, the models remains completely interactive and can be changed at any time by editing the runway criteria.

Key Features:

In addition to being a fully functional Geospatial Information System, i.e, able to import, and display layers of information from multiple sources (geo-tiff images, dxf, shape, vector mapping).

The unique features of GDMS are:

• System can work in local grid system or WGS-84 latitude and longitude.
• On screen creation of custom zones (Public Safety Zones, Restricted Airspace, etc.).
• Import and storage of eTOD data along with ICAO required attributes.
• QA analysis of legacy terrain data by comparison to ground truth points. Results will predict the accuracy or the legacy data at both 1 sigma and 2 sigma confidence levels. User can accept this result and add to the QA attributes for that particular terrain file.
• Full 3d visualisation with vertical exaggeration.
• Full Image draping onto terrain data.
• Automated Aerodrome Surfaces modeling. (User specified parameters, e.g. Annex 14 or other National variations such as the UK’s CAP168).
• Object analysis to all visible surfaces. (typically proposed planning applications or existing obstacles).
• AIXM ready database.
• Graphic screen can be split to a second screen (requires graphics card).
• Output to Google Earth (obstacles and surfaces)
• Technical support provided by SLC Associates, highly experienced aviation consultants and Geospatial data experts.

eTOD Sources

AREA 1 - Shuttle Radar Topography Mission

The Shuttle Radar Topography Mission (SRTM) is an international research effort that obtained digital elevation models on a near-global scale from 56 °S to 60 °N, to generate the most complete high-resolution digital topographic database of Earth to date.

AREA 2 (3 and 4) - LIDAR

Airborne lidar (Light Detection And Ranging) measures the height of the ground surface and other features in large areas of landscape with a resolution and accuracy hitherto unavailable, except through labour-intensive field survey or photogrammetry. It provides highly detailed and accurate models of the land surface at metre and sub-metre resolution.

Lidar operates by using a pulsed laser beam which is scanned from side to side as the aircraft flies over the survey area, measuring between 20,000 to 150,000 points per second to build an accurate, high resolution model of the ground and the features upon it. Using LIDAR for DEM and contour generation is faster than using conventional photogrammetic techniques and less susceptible to data collection problems as data can be acquired during the day or night. However, this system is weather dependent and cannot see through clouds.

AREA 3 and 4 - Differential GPS

Areas 3 and 4 also lend themselves to a ground survey mission. By mouinting a geodetic grade DGPS Receiver on a suitable vehicle, these areas can be surveyed very quickly and at low cost. Typically in 3 to 5 days per airport.

AREA 2 - Airborne IFSAR

(Interferometric Synthetic Aperture Radar)

Airborne IFSAR is a fast, accurate, cost-effective source of elevation and image data. The orthorectified imagery can provide ground-control points that can be used to link satellite or airborne imagery to an IFSAR DEM for rectification.