22 September 2021

Surveying and scanning

One of the things we always do on our annual field trip is survey the estuary. And that field trip is decades old, so we have quite an interesting dataset that tells us if the estuary is filling up with sand. And now we have moved location. We will start from scratch again!

The first thing we needed to do was decide where we put our survey lines. Once we establish them, we are committed! You can only compare data if you use the same transect lines every year. I had asked Guy to put some lines on the map. I was okay with taking over the module organisation while Martin was away, but I was not okay with doing graphic things, as that is just unnecessarily complicated if you have RSI. I think it is bad enough I sustained a long-term injury because of work; I did not intend to aggravate it by doing graphic work for this module. Just having the extra module would be damaging enough. And Guy knows what he is doing.

In the weeks leading up to the actual field trip we made some changes, and on the Monday, Guy went out and set up temporary benchmarks. Now we had the final versions! And we would spread the surveying over two days. We would have 10 groups of students, so if you want every group to be accompanied by a member of staff, you need 10 of those too, of course. Which we don't have! So I had spread the surveying out over two days. 

We also developed the plan to use the laser scanner on this field trip. We had never done that in the south, but Martin actually had at least one research project going in our actual field area, and Guy had already gone out there to scan it. And the school photographer had been out there to do photogrammetry with the Ocean Sciences drone. It would be silly to not use that knowledge and these resources! And their focus had been on the dunes, and these are accessible during high tide. So that was perfect; the surveying has to take place during low tide, and then we could just do some scanning during high tide.

There had been a big complication with the software of the laser scanner having expired; I was really glad I had managed to convince the head of school to just cash out for a new licence. We have that now, and that means we can use the scanner now for years to come! The entire scanner is roughly 120 times more expensive than the software it runs on, so it seemed like a reasonable thing to do to just spend a little bit of money for an amazing piece of kit. So after surveying and lunch, we would head for the dunes and play with some expensive toys.

I got one of the transects high up in the estuary, and I got a lovely team of ladies to survey it with. And the weather was amazing! So we got started. The early bits are always a bit slow as the students haven't surveyed in a fair while (and neither had I, come to think of it), but soon we picked up speed. And that was good, as our transect was quite a long. But it was a nice job! However, we didn't quite pick up enough speed as both the tide, and the time we were expected to meet the others, were approaching at speed. At some point we decided to just turn around. We will finish this next year! This year we had lost some time with going through the process altogether, while time was ticking away. Next year we should just have a bit of a practice run after one of the low tide activities. Then we can all hit the ground running as soon as we do the actual transects!

Dei explains surveying; pic by SOS

Two of my group in action; pic by SOS

The neighbouring group; pic by SOS

Surveying lower down

The neighbouring group also had to turn back. The people further down in the estuary had shorter transects, so they managed to finish theirs. We now had a few minutes to quickly scoff some lunch, and then we had to make our way to the other side of the field area. We did a bit of a forced march! But we got there almost on time. And when we were all together we headed for the dunes where the scanner and the drone were already waiting for us.

Guy demonstrated the laser scanner. And he is a born entertainer! So even though the only thing the students can really do is push the occasional button on a piece of equipment, he made it riveting. And in the background, the drone flew around. The drone work was done in minutes! I suppose flying really speeds things up. Having to move a tripod around is a bit more time-consuming. And we had backup activities in mind, but we didn't need them at all. We pretty much had to rip the students away from him to get them to the bus. I suppose that is a good thing!

Guy and the laser scanner

The next day we did the same thing, but this time I didn't join. I had bargained a day off! I had so far attended every day in the field from beginning to end, and that meant I hadn't really been able to spend meaningful amounts of time on other things. And immediately after the fieldwork, Welcome Week would start, and I was also responsible for that. There also was some admin to do related to the field trip, so I did that as well. I was really glad to have a day where I could catch up a bit. And then I was somewhat rested for the last day in the field, where we would do some coring!

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