Tuesday, July 30, 2013

Far (far) away

Before being able to reach the (far far away) Enderby Land, we have to sail. And fly. And fly again.
With the planning of the Antarctic Division and the visit of the three Australian stations (Casey-Davis and Mawson), we had only two different choices to reach our far away Land. Leaving early in the season (October) or late. So finally, we are leaving with the Aurora Australis the 11th of October.

The first part of our trip will be to sail to Davis. At this time of the year, the sea ice is at its maximum coverage, and the ice breaker has to manage its way through.

Way from Hobart to Davis

Then once arrived in Davis, we have to fly. Fly to Mawson, and then to Enderby Land. No boat is accessing that area, and no "normal" plane is able to land there. So the Twin-Otters will be our taxi to reach the Tula Mountains and Richardson Lake. 

Davis to Mawson

Mawson to Richardson Lake

We don't have any plans once there. We will have to deal with the weather conditions and the Twin-Otters planning to reach our stations and install the GPS.

The rest of the voyage will be sightseeing: Fly from Mawson to Davis - then Davis to Casey and finally Casey to Hobart. Two months of travel in the "big white".

Way back: Mawson-Davis-Casey-Hobart

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Tuesday, July 2, 2013

Building GPS stations


To survive in Antarctica, the stations have to be completely autonomous and resist to the cold and windy conditions. 

To answer these requirements, we will set up a couple a solar panels that will recharge three batteries. Because of the polar night, the systems will hibernate through the winter period and, all going well, will recommence operation around August/September each year (when the sunlight is sufficient to recharge the batteries). An iridium modem and antenna will allow us to get the GPS (Global Positioning System) data transmitting them from Enderby Land back to Canberra. The structure has to be heavy and fixed to the rocks. The batteries, GPS and electronic circuit are protected in a insulated box, that should keep the warmth produced by the electronic equipment and the heaters.

The structure

Each element of the frame is logically numbered to facilitate their setting in the field. The structure is metallic, so heavy and resistant. It then has to be oriented in the Northern direction to provide the maximum solar light in a day.

Bianca installing the main frame on the roof

With the solar panels and the iridium antenna

The Electronic circuit

The circuit is installed in the insulated box and is composed of:
- One GPS
- Three batteries
- Three regulators
- A card frame composed of a small computer and a Power Controller
- An iridium modem
- Heaters, temperature probes etc...

The Solar panels will recharge the batteries. The Power Controller (PCON) will then separate the power between the Computer, the GPS and the modem. If any power cut occurs, a filter board will prevent any damage on the GPS or on the computer. 

The three batteries and regulators isolated in the box. The GPS has to find its place in there...

At the end, the system is sending every day the data acquired by the GPS, transformed into ASCII format and compressed by the computer, through the modem and iridium antenna. Away from the "wake-up hours", so when the computer is getting the data from the GPS and sending them via the iridium, the system is set to "sleeping mode" to reduce the power supply.

The card frame controlling the "waking" and "sleeping" state of the system and recording/processing the GPS data.