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DG-TAWS Prototype project

Prototype of a Terrain Awareness and Warning System


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What is TAWS?
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TAWS stands for Terrain Awareness and Warning System. It is an avionic that is installed aboard the aircraft and it makes visual and sound warnings if detects that the aircraft is in a dangerous path towards terrain.

It bases his alerts on a GPS Receiver to retrieve position and other navigation information. It uses DAFIF to identify airports/runways and SRTM 3 as terrain database.

This program was made for my Aerospace Eng. 5yr Graduation and it follows the guidelines of the FAA TAWS Standards TSO-C151c.

Feel free to take a look at the slides that were used to present this project to the Royal Aeronautical Society in 2008

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Featured TAWS Alerts
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- Forward-Looking Terrain Awareness
- Excessive Terrain Closure (500 ft)
- Altitude Loss after Take Off
- Premature Descent (When Landing)

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DG-TAWS uses a GPS receiver as source of navigational information. The GPS must be connected to a serial port of the PC, and its interface must be configured as NMEA 0183.

After this, the OpenGPSServer program must be started and user must press 'Start Connection'. This program will broadcast current navigational information through the System and after this, TAWS program can be started.

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Here is a screenshot of the DG-TAWS program: (Full Screen Display)

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The display is another item that follows FAA Standard TSO-C151b, the terrain map is oriented with current aircraft direction. Terrain above aircraft level is shown on red, terrain from the aircraft level to -500 ft aircraft relative is shown on yellow and from -500 ft to -2000 ft aircraft relative, terrain is shown on green.

Along with the shown concentric lines, this coloring enables the pilot to estimate bearing and distance of all terrain features. Concentric lines with same distance from aircraft are shown with distance on right, and time to achive them on left.

Course is shown on Upper-Left corner, and on Bottom-Left Corner you can use mouse to increase/decrease zoom.

On the opposite side, you can watch: Ground Speed (in knots), Vertical Speed (in ft/min) and Altitude Above Ground Level.

Alerts are shown on Red or Yellow, and in case of a Forward-Looking Terrain Alert, time to collision or 500 ft violation is also shown.

On the map derived aeronautical information is also displayed, namely: nav-aids, airports and runways based on NGA (former NIMA) DAFIFs.

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To test DG-TAWS:
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The TAWS Program is small sized but terrain and airport databeses are large. Please note that it is also needed a GPS receiver, NMEA 0183 compatible.

Click here to download a test TAWS with San Francisco, California scenery.

A small video of the TAWS Flight Test, made aboard an Cessna 182, is available here.

If you wish to test DG-TAWS in your area, please send me an e-mail with the coordinates of your airport and I will supply the executable along with the data of the surroundings.

Keyboard assignments on TAWS program:
- 'z' and 'x' - Increase/Decrease zoom.
- 'a' - Force the 'near airport flag' , this will disable 500 ft warning
- 's' - This will save current aircraft track on a GPS Track Maker Text file called 'exp.txt'.

- DG-TAWS is not certified for real aviation use. It is intended to use just for fun and scientific purposes and not for real Controlled Flight Into Terrain avoidance. The Author will not be responsible in any case, so use it at your own risk.

- Also remember, that FAA TAWS Standard TSO-C151b states that only GPS Receivers that comply with TSO-C145 are suitable as stand-alone navigation sources for TAWS purposes.

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Feedback and References
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- For other programs that mix terrain data and GPS information checkout DG Terrain Viewer.

- Use DG-Void Killer to correct SRTM terrain data.

- Use DG-Earth Tracker to use your GPS receiver, real time with Google Earth.

- Slides that were used to present this project to the Royal Aeronautical Society in 2008

- Stay Tune:
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- Send me an E-Mail Using this Form

- Other Contacts:
Tel: +351-91-832-5222

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