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22nd - 23rd May 2018

GEObusiness - London

Attendance Report

Attended by: Tomaz William Assunção

Prepared by: Tomaz William Assunção

Seminars/Workshops attended

Day 1

  1. How do you complete accurate surveys with drones?

Speaker: Keith Wakeley | Company: Drone Pilot Academy

  1. Next generation software Cyclone, JetStream and CloudWorx

Speaker: Nicollete Beggache | Hexagon/Leica Geosystems

  1. Surface deviation maps created from laser scanning for non-technical client personnel

Speaker: - | Company: Murphy Surveys

  1. Direct Geopositioning with low cost drones

Speaker: Lewis Graham | Company: GeoCue Group

  1. Handheld 3D scanning and real time processing

Speaker: - | Company: DOT Product

  1. Ultra wide band ground penetrating radar – New applications

Speaker: Luke Steadman | CAT Surveys – Intelligent surveying

  1. Special applications of ground penetrating radar for drones

Speaker: - | Company: Geoscanner

  1. GPR data processing

Speaker: Mike Langton | Company: MALA Geoscience



Day 2

  1. Heritage: Different Paths to the same destination – How Historic England is using a range of techniques to produce complete point clouds

Speaker: David Andrews| Company: Historic England

  1. Geophysical surveys – it’s not all GPR!

Speaker: Mark Whittingham | Company: Phase Site Investigation Limited

  1. Drone Surveys – DIY or hire contractors?

Speaker: Mark Jones | Company: RUAS



Seminars/Workshops review - notes - impressions

Day 1

  1. How do you complete accurate surveys with drones?

Accuracy – this was one of the major areas pointed out by the speaker during his presentation. He pointed out two key measures of accuracy:

GSD (Ground sampling distance) – relates to the pixel size to the ground, so a GSD of 1cm means that 1 pixel of the camera equals to 1cm2 on the ground. The higher the GSD the less accurate it will be. On the other hand the better the camera sensor the lower the GSD (more accurate) for the same height.

From what I gathered the GSD and overlap are key factors for good accuracy. The higher the drone flies the higher the ground sampling will be and with bigger/better camera sensors you will achieve better quality data. Also increasing the overlap will improve greatly the final data.

It was also pointed out the need for GCP (Ground Control Points) and the benefits of this as they set the absolute accuracy of the survey to the output grid and it also improves the relative accuracy and allows the accuracy to be measured via independent means and finally proves o the client that the accuracy being claimed is the correct.

Setting GCP out: you need to set at least 5 out, they need to be well distributed, need to be placed a overlaps of flights and they need to be positioned having in mind the surveyors that will use them in future.

Flight plans for:

Flight planning software and quality control: Pix4D

We can usually get a 20-25mm accuracy while using a double grid.

Photogrammetry course: 495+VAT for more details visit https://www.dronepilotacademy.co.uk/courses/surveying/

  1. Next generation software Cyclone, JetStream and CloudWorx

This second workshop was more orientated to Iuliana (laser scanning), but since she couldn’t attend I stepped in.

Cyclone: Powerful 3D pointcloud processing software wih great registration flexibility and export capabilities. The latest version (9.2.1) incorporates some new features including:

This comes with the benefit of shorter registration times and easier visual presentation interpretation.

JetStream: provides the seamless use of your point cloud data with instant loading of all points;

CloudWorx: is a software application that allows users to take advantage of rich 3D point clouds directly within their CAD drawing environment.

  1. Surface deviation maps created from laser scanning for non-technical client personnel

???????

Differences between a traditional workflow and a laser scanning workflow:

Comparing the laser scan survey with the design details is a good way of picking up flaws has it provides checks against the design models. However good control points are needed if you want to achieve low tolerances.

In summary:

However there is little control over the measured points, therefore:

  1. Direct Geopositioning with low cost drones

???????

For volumetrics/inspection/small site surveys: DJI inspire 2 with X4S camera is a fine solution costing around 3,750$ USD.

For high accuracy mapping we need:

It was interesting to find out that a good mapping camera needs to have a mechanical (electronic global) shutter like the X4s (Inspire 2, m200) or the Phantom 4 Pro.

Cameras that aren’t good for mapping:

Summary:

  1. Handheld 3D scanning and real time processing

???????

This presentation was really interesting and I think it has real potential to be implemented in the future if the company picks up more laser scanning jobs.

Traditional laser scanning and some challenges:

The solution presented by DOT are the handheld 3D scanners: DPI-8X and the DPI-8X SR composed by a 3D sensor + tablet + Phi.3D Software + Dot3D Edit Software.

Main features are:

Some other notes: 1m distance of desired object to start scan; 1-2mm point spacing.

  1. Ultra wide band ground penetrating radar – New applications

???????

What is ultra wide-band GPR?

Benefits:

Travel speed is also important in the sense that the faster you move the equipment the lower the density of recorded data you will obtain. Inversely, the slower you move (10-15mph) the higher the density of the data.

  1. Special applications of ground penetrating radar for drones

???????

The main goal of Geoscanner is to develop a drone mounted GPR system and apply it in mine field areas. However the biggest problem they face and are trying to solve is the accuracy of their GPS system, as they aren’t getting real time precisions when moving – solution could pass by implementing RTK or TS. It seems to have potencial especially since the deliverable would be in a heat map, and areas of higher values (possible mines) would show up nicely.

Another issue with the drones are the payloads - limited to 1kg.

Further applications:

Potentially up to 1m penetration in good conditions. Drone needs to be flown 1 to 1.2m above ground level for the best results.

  1. GPR data processing

???????

To be honest I expected a bit more from this workshop however it was still interesting. The speaker just went through very basic processing steps and showed us some examples applied to the detection of utilities.

GPR in utility surveying, what we need:

Some common processing and analysis steps for GPR data:



Day 2

  1. Heritage: Different Paths to the same destination – How Historic England is using a range of techniques to produce complete point clouds

???????

Interesting seminar about how Historic England keeps records of historic buildings – using photogrammetry and laser scanning – and how this data will help us and our future generations to appreciate historical buildings and potentially help restore the ones in need of repair.

Why combine point clouds:

  1. Geophysical surveys – it’s not all GPR!

???????

Slightly disappointing workshop, I had a bigger expectation with what would be discussed. General comparison between GPR surveys and resistivity/conductivity surveys with some case examples and how data ties in together.

  1. Drone Surveys – DIY or hire contractors?

???????

Again, this was a very interesting workshop that gave the attendees an overlook of all that is needed prior to any survey and general costs involved with this kind of equipment.

Before you have permission to operate the company needs the following standard permits:

Cost-evaluation:

Savings:

Risks with out-sourcing:

For Your Information:

I also visited the IDS-Drilline’s stand and spoke with Valter Baroncini about some high frequency ground penetrating radar that we could possibly use in future jobs. He showed me the new C-thrue and we tested it out and from what I saw it’s a pretty good piece of kit for accurate scanning and real time analysis of concrete structures (locate rebar, voids, post-tension cables, cavities, conduits, etc).

Important note: Valter also mentioned that he is available to come to our Swindon office to give a live demonstration of the C-thrue for free. I think this is a good opportunity for myself, Jose and Kieran to test out the product in a controlled environment.

Features and Benefits:

The C-thrue software system automatically recognises and discriminates rebar and voids in concrete structures.

The software is specifically developed and suitable for in the field analysis:


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