Thursday, 26 April 2012

Experiencing the highs and lows of Welsh weather...

Monday- If you fail at first, try, try, try and TRY again!

The new calibration point
With the weather forecast promising a good weather window on Tuesday, Monday was a day of last minute preparations. The cliff observation team headed up along the coastal path with Felix to measure the calibration point for the theodolite as well as the position of the buoys marking the location of the PODs. While Marta and Winnie began measuring the position of the buoys, Felix and Gemma set off to measure the calibration point for the theodolite; a white MOD trailer located further down along the coast. Unfortunately, this expedition was soon met with complications; possibly because it is the property of the Ministry of Defence, Gemma and Felix could not get close enough to measure it. Not wanting to compromise national security but in desperate need of a measurable reference point that would allow us to calibrate the theodolite, the decision was made to choose a new point, a large corner fence post. Changing the reference point, however, meant that all buoy positions Winnie and Marta had been busy measuring, now could not be used anymore and that all measurements would need to be redone. Although initially frustrating, it was still a good exercise, allowing the cliff observation team to get familiar and comfortable in the use of the theodolite.

Later that day, it was still too rough to take the boat out but the team spent most of the afternoon preparing the Islander for the promised lull in the wind. The famous 'Culticave', was also allocated a permanent position on the boat and was successfully set up and secured on deck. Felix also used this time to measure the boat and array with the inertial measurement system which compensates for the rotation roll, pitch and angle of boat as well as measuring the angle to the north during acoustic recordings, this way we will be able to tell how the roadie bar is aligned at all times. However, these measurements had to be cut short due to the quickly rising tide. On dry land, once again, Winnie, Felix and Jens spent a long evening disentangling hydrophone cables, ensuring they were coiled separately and safely and ready to use the following day. After a long day, the team headed home, hoping for better weather for Tuesday.

Tuesday- All systems go!

Preparing the acoustics equipment
Tuesday was the big day, the window of opportunity we had all been waiting for! With the wind predicted to be at an all time low in the afternoon, there was an air of anticipation around the house as everyone did their bit to ensure that the first run with the full hydrophone array would be a success.
The array was assembled on the pier, and for the first time, the hydrophones attached! All electrical equipment, 2 laptops, batteries, the recording unit and amplifier, was assembled under the protective cover of the Culticave. Originally designed to be a greenhouse, it also very efficiently retains heat, which may prove to be a bonus on cold days, but was a bit of a concern in Tuesday's atypically sunny weather with not only all electronics but also Jens and Felix squeezed snugly under it's protective plastic roof! Finally, after breaking for a well deserved lunch in the sun (including home made cream tea courtesey of Hanna and Kati!), the cliff observation team, Marta, Winnie, Gemma and Katrin, set off to prepare the site while the boat team, Hanna, Luke, Felix, Jens and Kati, made last minute adjustments, ready to set off as soon as the last white caps disappeared from the horizon.

Calibrating the theodolite
Having had plenty of time to practice on the friendly neighbourhood cows, and encountered and resolved many error messages under the careful guidance of Felix, the cliff team confidently set up the theodolite- just to be set upon by error upon unknown error! Undeterred, they consulted the manual, made notes and tried the well known 'switch it off and back on again' technique, before resorting to calling Felix on the boat who swiftly resolved the issue once again. Calibrated, centred and ready to go, the team was now ready to record the positions of all the buoys marking PODs (all of which were present and intact despite the scare with Patricia!), as well as scanning for cetaceans and keeping an eye on the Islander.

Meanwhile on the boat, the first trial run with all hydrophones in the water was in full swing and although there were no animals in the vicinity to record, the boat team successfully recorded and located the echosounder using the acoustic array! Despite the limited practical application of this achievement, it was nevertheless a very important step forward, as it allowed the team to test whether the equipment was working correctly. They also had some time to attempt the first playback experiments; playing back sounds with the aim to study the likelihood of the static PODs picking up sounds at different volumes and distances. In the early evening, with storm clouds gathering overhead, the wind picking up again and the rumble of distant thunder in everyone's ears, both teams headed home after a successful day!

Islander as viewed from the cliff top observation point

Wednesday- Gone with the wind-again

All hopes of resuming boat or cliff based work were literally gone with the wind early on Wednesday morning. As gale force winds racked New Quay, there was little to do but to resign ourselves to the fact that we would be confined indoors for most of the day. However, as always there was plenty of odds and ends to do -such as updating the blog and replenishing our diminished food supplies as well as downloading data from the theodolite and working out the kinks in the electronic set up.

In the afternoon, Felix, Luke and Katrin headed back down to the Islander to complete the inertial measurements during low tide. Waiting patiently for the waves to retreat, the flooded 'Culticave' was dried out and the electrical equipment set up while further storm clouds gathered overhead. Slightly concerned about this development, as some of the measuring equipment is sensitive to water, the team checked the time to gauge how much time they had to complete the measurements- only to find that low tide had come and gone and at no time had Islander been completely on dry land! Unfortunate as this development was, we resigned ourselves to the fact that the weather and tides were not under our control and headed back home.
Waiting for the low tide that never was! 

Meanwhile, Hanna had checked the weather and discovered a brief good weather window early on Thursday morning- however just how early 'early' was remained a matter of mystery and much discussion for a while. We did not have long to dwell on this somewhat ominous announcement as Jens commanded all our attention for a pre-dinner talk on TOAD; Time of Arrival Difference, the method used to localise vocalising animals using a hydrophone array. After dinner the real meaning of 'early' was finally revealed and we headed straight to bed to be awake- bright and 'early' the following morning!  

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