Pilbrow Surveying Limited
X100 Fact Sheet
Why did we choose the X100?
Safer method of surveying stockpiles and quarry faces
Adds another option when deciding the most cost effective survey method
Enhances current outputs by supplying an aerial image
Capable of handling NZ weather conditions
Will survey the tops of stockpiles which ground based scanners can’t do
What are the X100 specifications?
Ground Sample Distance @ 100m = 3.3cm
Up to 40 minutes per flight
Up to 100 Ha per flight
On site for only a few hours per flight
Operates below cloud cover
Handles winds up to 12 m/s (25 knots)
Expanded polypropylene reinforced with a carbine fibre skeleton
Weighs only 2kg
Powered by a lithium polymer battery
Propelled by an electric motor at the rear
Cruises at 75 km/hr
How does the X100 operate?

Check weather conditions
Check body condition
Check launch & landing clearances
Set scan area & upload flight plan
Launch
Scan area with parallel sweeps and overlapping camera shots
Monitor flight with ground control station
Land
Download files - images & GPS coordinates
Align images
Input ground control point data
Build Geometry
Output data - DTM, contours, ortho-photo, linework
What will it cost?

Flying
Site establishment
Per flight fee
Ground control requirement

Processing
Per Ha
Cost dependant on final product - Ortho-photo, DTM, Linework
A few hours to a few days
Why choose Pilbrow Surveying Limited?Text Box: Fact Sheets and Articles

Supplying construction surveying services to the Auckland and Waikato regions since 1996

54 Scott Rd, RD2,

Te Kauwhata, 3782

Phone: 07 8264337

Fax: 07 8264337

E-mail: PilbrowSurveying@xtra.co.nz

Text Box: Why Choose Pilbrow Surveying Limited?
Text Box: What we do
Text Box: What we have done 
Text Box: What others think
Text Box:  Who we are
Text Box: What gear do we use 
How many stakes has Pilbrow Surveying Limited banged in so far this year?

Stakes banged in this year =  1893

Pilbrow Surveying Limited construction earthworks surveyors logoPilbrow Surveying Limited, the first company in New Zealand to be using the Gatewing X100 aerial mapping systemLink to page outlining the Gatewing X100 aerial mapping system in use by Pilbrow Surveying Limited, the first company in New Zealand to be using the system.

0800 PSL NOW                PilbrowSurveying@xtra.co.nzWhy choose Pilbrow Surveying Limited?Text Box: FAQ’s
Text Box:

54 Scott Rd, RD2, Te Kauwhata, 3782, New Zealand Phone: 07 8264337, Fax: 07 8264337, E-mail: PilbrowSurveying@xtra.co.nz

Text Box: Why Choose Pilbrow Surveying Limited?
Text Box: What we do
Text Box: What we have done 
Text Box: What others think
Text Box:  Who we are
Text Box: What gear do we use 
Pilbrow Surveying Limited construction earthworks surveyors logoText Box: Current news
Link to page outlining the Gatewing X100 aerial mapping system in use by Pilbrow Surveying Limited, the first company in New Zealand to be using the system.

0800 PSL NOW                PilbrowSurveying@xtra.co.nzWhy choose Pilbrow Surveying Limited?Text Box: FAQ’s
Waikato Times Article on drones from January 13 2013 featuring Rodney Pilbrow from Pilbrow Surveying Limited and their X100 UAV for aerial mapping.Article from Holcim magazine about X100 from Pilbrow Surveying Limited and its use at Bombay Quarry
Link to X100 summary Fact SheetLink to Waikato Times article on drones featuring Pilbrow Surveying Limited X100Link to article from Holcim magazine featuring Pilbrow Surveying Limited X100 operating at Bombay QuarryPilbrow Surveying Limited
The Role of a Construction Surveyor in Quarry Operations
We believe the primary role of a Construction Surveyor is to give
clients total peace of mind with regard to their surveying needs.
Here are some of the things that we as specialized construction surveyors can do for you:
Site Plans & Visualizations for Resource consents, quarry planning, traffic movements, daily   operations, plant upgrades, face updates, back fill scheduling, noise & visual screening design
Volume Calculations of stock for financial audits & inventory management; overburden for          tendering & contractor payment; resource for extraction rates & reserve mapping
Survey, Setout & As Built of New plant, infrastructure, sediment control ponds, stripping limits, face extents, boreholes, waste dumps, water supply dams, bench & highwall safety audits
Link to page outlining the Role of a Construction Surveyor in Quarry Operations

Need more information Call 0800 PSL NOW

Pilbrow Surveying Limited

What do you want to know about the X100?

Text Box: Current News Blog
Text Box: Flying
· Site establishment
· Per flight fee
· Ground control requirement
 
Processing
· Per Ha
· Cost dependent on final product - Ortho-photo, DTM, Linework
· A few hours to a few days
Text Box: · Ground Sample Distance @ 100 m = 3.0 cm
· Ground Sample Distance @   75 m = 2.1 cm
· Ground Sample Distance @   50 m = 1.5 cm
· 10 minutes per flight with hot swap capability for large areas
· On site for only a few hours per flight
· Operates below cloud cover
· Handles winds up to 10 m/s (20 knots)
· Weighs only 6kg
· Powered by a lithium polymer battery
Text Box: Pilbrow Surveying Limited
X8 Fact Sheet
Text Box: T win Autopilot, Twin GPS, Four sets of Twin Rotors for safety
 Parachute system to provide ultimate protection
 Capable of handling NZ weather conditions
 Vertical take off and landing makes it suitable for enclosed areas
 Quick to deploy
· Autonomous flight path with ability to take control if necessary
· Return to Home function if radio connection lost
· Comprehensive Flight training on Blade QX multi-rotor
Text Box: · Check weather conditions
· Check body condition
· Check launch & landing clearances
· Create & upload flight plan
· Launch
· Scan area with parallel sweeps and overlapping camera shots
· Monitor flight with ground control station
· Land
· Download files - images & GPS coordinates
· Align images
· Input ground control point data
· Build Geometry
Text Box: How does the X8 operate?
Text Box:         What are the X8 specifications?
Text Box:                                                      Why did we choose the X8?
Text Box:                                                     What will it cost?
Altus Delta X8 used by Pilbrow Surveying Limited for low level aerial mapping

X8

 

In what format can I get the resulting images?

The electronic format which most people use is a jpeg file with an associated jgw world file. This allows the orthophoto to be brought into CAD packages in the correct real world position. The other format commonly used is a GeoTIFF. This format contains the location data embedded in the file rather than a separate file. It is also possible to supply the image as a png format. Another useful format which is not strictly an image format is kml & kmz which is opened and viewed in Google Earth. The image location has to be transformed to WGS84 coordinates to be used in Google. If the image is to be spread around non-technical people then having it as a pdf file is more useful as most can now open pdf files. Due to the high quality of the images resulting from the X100 surveys the image files can be very large and some computers are unable to open such large files. Saving the image to a pdf at a given paper size allows the image quality to be optimized to that paper size and gives smaller more manageable files. A cool option for supplying imagery is a 3D pdf. From the raw photogrammetric data a pdf file can be extracted that can be manipulated in 3D. We have supplied many of our clients their images onto waterproof PVC which enables them to be taken into the field and used without having to worry about them disintegrating. Another option is having the image put onto a whiteboard. This can be mounted on site and the up to date high resolution image used for daily work allocation or weekly planning sessions.

In what format can I get the resulting data?

The format which is requested by most clients is dwg or dxf. This can be imported by most computer software programs and is able to directly call the image file when opened. We use both LISCAD and 12d for our data processing so files can be supplied in these formats. We are also able to export to a number of other different formats commonly used by engineers. For GIS use we will export ESRI shape files of the contours, model boundary and linework and the DEM as xyz data. It is also possible to export to various 3D formats and supply csv files of the data.

Where can the X100 be used?

The X100 has being used around the world in such diverse situations as archeological mapping on the Easter Islands, a new nuclear power station in the UK, forest mapping in Belgium, oil spill monitoring in Curacao, mines in Australia and of course here in NZ we have used it for quarries, landfill and earthworks. The X100 can be used for most places that you might want to get surveyed. There are some restrictions imposed by the Civil Aviation Authority for the use of the X100 but these are quite specific and do not apply to many sites. As the X100 operates below cloud cover, in winds up to 12 m/s there are few times when it would not be possible to use it for your site. Our normal flying height is 100m above ground level which gives a ground sample distance (the size one pixel in the image will cover on the ground) of 3.3 cm. There are some sites where the local terrain will prevent the X100 from operating at altitude as we must fly high enough to clear the surrounding hills. This will degrade the resulting accuracies which are based on the flying height but it can still be used.

What sort of sites have you used the X100 for?

We have used the X100 in quarries, landfills and earthworks sites from Geraldine to Whangarei, Marton to Whakatane. It has been used to calculate volumes for stockpiles, overburden removal, landfill capacity and bulk earthworks. We have supplied data to others to use for planning of future quarry faces, overburden disposal areas, civil design and landfill planning. Images have been used as site plans for quarry and landfill management, site plans for consent purposes and aerial views of a property for a birthday present.

How does the system transform 2D images to 3D data?

The full explanation of this is quite long-winded and is being covered in a series of articles in our bi-monthly newsletter. The 2D images which are captured by the X100 during its flight are loaded into the software with the GPS positions of the images used to give an initial estimation of their position. The software then looks for pixels which are matching in different images. 40,000 points are selected in each image and used to find matches. With this matching the location of the images is refined. The next step is to place the surveyed locations of the ground control points in the relevant images to allow the data to be geo-referenced more accurately. An exceedingly complicated best fit calculation called a bundle block adjustment is carried out on the data to establish the position and orientation of each image. Matching pixels then have a 3D location extracted by intersection from different images. This builds up a point cloud of known 3D points which forms a triangulated surface model. This surface is then used for volume calculations, contour extraction and formation of the ortho-photo.

 How does it differ from traditional photogrammetry systems?

Traditional aerial photogrammetry is carried out using large format specialized cameras from planes. A minimum of three height and two plan ground control points per stereo pair are required. The images are captured with a 60% forward and 25% sideways overlap. To ensure that there are no clouds obscuring the images, flights have to wait until clear skies are expected. To avoid major shadowing of the images the flights must be carried out when the sun is fairly high in the sky further restricting the times that are suitable for imaging. The resulting accuracy of the data and resolution of the image is based on the scale of the final plan, usually from 1: 5,000 to 1: 50,000. With low level aerial photogrammetry a standard digital camera is used. This is then calibrated for optimal results. Images are captured with a 75% overlap in both directions to ensure good matching between images. Ground control points are placed out to encircle the area to be surveyed and at high and low points within the area. For a 50Ha area with lots of elevation difference we would use 25 GCP's. The large number of GCP's improves the final accuracy of the data. We fly the X100 at less than 125m above ground level so will be below most cloud cover. This means surveys can be carried out at almost any time. Due to the low altitude of flight the resulting ground sample distance (the size one pixel in the image covers on the ground) for most of our survey is 3.3cm.

What accuracy are you achieving? How are you verifying the resultant data?

The combination of the low flight altitude and the large number of ground control points allows us to achieve the following average error between the surveyed GCP's and the values found following the processing: x = 0.019m, y = 0.019m, z = 0.033m. These are average values from eight recent surveys which range between: x = +/- 0.05m, y = +/- 0.05m and z = +/- 0.10m. The processing extracts a very dense surface model up to 200 points per square metre which we usually decimate down to create a more useable file size. This is far more data than would have been surveyed using GPS or total station methods. Initially we carried out check surveys of areas and found very good matches between the GPS surveyed points and the corresponding position in the resulting terrain model. However we rarely do this any more as we have become more confident in our field and computing systems. A recent flight at the Steel Mill covered an area of pond liner which had been surveyed by GPS a few months before. Comparing the two surveys found the vast majority of the GPS points to be within 50mm of the X100 model but the X100 data was on an approximately 1m grid while the GPS was a 4m grid giving a far more detailed surface.