Global Positioning Systems


Each PHL helicopter typically carries multiple GPS devices; each serving a different purpose.

Spidertracks GPS

The spidertracks GPS is used primarily for Flight Following. At specified intervals, spidertracks sends a signal with three-dimensional GPS coordinates of the helicopter at that moment in time to the Iridium network of 66 orbiting satellites, which is then beamed back to Iridium’s Earth station and on to secure servers in New Zealand or Australia. The GPS coordinates are translated into a visual record of the craft’s flight path and overlaid on to topographical maps.

Spidertracks also enables the pilot to report departures, landings and any emergencies.

Aerial view of helicopter

Garmin GPS

The Garmin GPS provides accurate details of the flight information for analytical or reference purposes.

For such tasks as aerial surveys, customers can provide coordinates that are subsequently loaded onto the devices so that the pilot can navigate a specific route. Waypoints of interest can also be entered.

Once the flight is complete, the actual flight information can be downloaded and supplied back to the customer. Unless another format is requested, we provide this information as a Google Earth file because it is freely available and has amazing dynamic capabilities. The following film shows a bird's eye view of the same path the helicopter flew. (Note that the quality is much higher when running in Google Earth.)


Trimble GPS

The Trimble GPS is used mostly for agricultural work. The system is designed to meet the precise positioning demands of the aviation industry in the fields of material application. The system uses the latest satellite navigation technology, differential GPS, to obtain positioning with typically less than 1 meter accuracy in real time. It is suitable for all weather conditions, all terrain, and for use at low altitudes.

The system allows the pilot to define the extent and format of flight operations, and provides accurate tracking along an assortment of patterns. The system displays a clear picture of the helicopter’s location relative to topographical features, hazards, block boundaries, and flight lines. It informs the pilot where to start and stop runs, and warns when entering avoidance zones. The aircraft position and speed, along with other relevant data such as spray widths, are continually recorded during flight. This enables us to generate field reports and plots, as well as files for post-processing.

We can output the data again in various formats to suit the client, although we find that a Google Earth file is the most useful. The client can see exactly the extent of the aerial application.

Helicopter Spray pattern from GPS

Providing GPS Coordinates

We prefer to receive coordinates using the WGS84 datum and ideally in decimal degrees. The simplest method of providing us information is by emailing a Google Earth file which we can easily translate.