First results from drone flight over Croxtons

On Saturday 21st Jan 17 we flew a drone over Croxton's Field to product aerial photographs and digital elevation models to see the condition of the trenches dug over the past few years.  These are some of the early images that have been produced.

1. Aerial photo

2. Crop health (trenches in red)

3. Elevation model (remember the field is quite flat)

4. Slope direction shader

Aerial photography comes to Waterless Brook Project

Last Saturday I attempted my first archaeological survey by drone.  Lots more to learn, but I have managed to get some decent results from the first flight. I didn't get the drone exactly over the middle of the feature so the smaller cell is not as clear as the larger one.  All part of the learning curve.

Basic analysis - Overhead shot (Fig1)
Hover over a feature as low as a few meters to over 100m.

Extract from Video (Fig2)
Using a 'Point of Interest' feature the drone will circle round filming the ground.  Images are then extracted from the video (every 4 seconds) which will be used to produce a 3D model by photogrammetry.
These give a more angled image.

Create a 3D model (Fig3)
Using photogrammetry software a selection of overlapping images taken from all angles around a feature can be used to produce a 3D model.

This model is about 100 times more detailed than the one I have tried to create from lidar, so very promising.


Next Steps
Now that I can produce a detailed model (point cloud) from the video, I need to find a way to convert it back to raw data, so that we can do the hill shade and elevation analysis to produce drawings, possibly to within a few centimetres accuracy.

Fig1: Overhead shot

Fig2: Frame from video

Fig3: 3D model created by photogrammetry software

What would one of the jugs look like if reconstucted?

I need an outline of a medieval jug to reconstruct.  

I have found this in a report from the medieval kiln in Audlem, Cheshire.

What did the Kiln look like?

I have stumbled on a excellent (free of course) CAD package, and to learn how to use it I have started to recreate the kiln.

This is my 5th attempt! (first attemt at a fire!)

Next I will add arrows to show the flow of air/heat.

C

First report of feature in south field from October 2015

Hi, as winter approaches and we will be shutting down the main trench, I have been looking through the archives and thought it was about time we had a look again at the feature in the south field. There is a rectangular feature that may be a fishpond or something else with a curved boundary next to it.  Strangely, it has a distinct cinder layer just under the top soil.

Here is a link to the initial report written in October 2015. (please let me know if the link to the document does not work, I am experimenting 8)

I will post the second report when I find it.

C

Feature in south field behind the house

Google Earth 2000

First drawing of context 52 (red layer)

For the first time this week we could see the extent of context 52 so a drawing has been produced.

Plan Number: 02

In the above plan, context 52 is shown in red.  It consists of an equal mixture of red pot and kiln material.  There is little or no glazed pot.  It is adjacent to the kiln and sits on top of context 52 which looks like a 2cm thick layer of clay/mud with a large amount of charcoal in it.  It is directly under context 43, the black pot filled layer.

Context 43 runs over the top of the kiln (black dotted line indicates estimate) as evidenced in the section behind the kiln, so must have been deposited after the kiln went out of use.

Context 52 is up against the side of the kiln, so was most likely deposited after/during the last firing(s) of the kiln.

Overhead shot from 3D model

In depth anlaysis of Ashton lidar

Hi all,

I have looked in more depth at a feature Alison highlighted (Feature B) on the Ashton lidar published earlier. 

On the 1945 Google Earth image there is a area along the hedge line in this position. You can see on the 2016 image that the hedge line has been moved and Feature B is now covered with trees.

Google Earth 1945

Google Earth 2016

I have created a 3D model of that area which shows an area of disturbance at Feature B. The 'lumps and bumps' are about 1m high.  There is also a 1m deep depression showing up as well in the other field.  On some of the aerial photos this depression is visible.

1,2 and 3 are hedgelines: 4 is Feature B: 5 is a depression

Now, the lidar data only samples every 2m, so there has been a lot of number crunching to create this model, but it is interesting that something is showing up in this area.