67th msps annual meeting - 2019€¦ · 67th msps annual meeting - 2019 unmanned aircraft systems...
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67th MSPS Annual Meeting - 2019
Unmanned Aircraft Systems (UAS) As a
Tool for Land Surveyors
George Southard
GSKS Associates LLC
George Southard:
Master’s Degree in Photogrammetry and Cartography
40 years working in the mapping industry
Owner – GSKS Associates LLC
“Consulting for the Geomatics Profession”
Introduction
Why Use a small UAS for
Photogrametric Mapping?
• Create accurate geometric map products; like,
topographic maps, planimetric maps, orthophoto
maps, etc. of relatively small areas of interest.
Small UAS can be used to:
• often cheaper, and faster than by terrestrial
methods,
• in areas inaccessible by ground crews,
• with very high accuracy and precision.
and they can do it :
Why small UAS/Photogrammetry?
This technology is ideal for measuring areas or
objects such as:
– Areas to be mapped are 20-600 acres
– Corridors – Electric utilities, pipelines, etc.
– Objects/areas that are too
• Hot or cold
• Soft
• Delicate
• Danergerous
• Inaccessible
• Toxic or Radioactive
Why small UAS/Photogrammetry?
Large (Predator Drone)
Medium UAS (weighs 90 lbs.)
sUAS (Small Unmanned Air System)
1lbs < 55lbsMicro (MAV) less than 1lbs
A Variety of Types and Sizes
Rotary
BlimpFixed-Wing
A Variety of Types and Sizes
Traditional Surveys vs. UAS Surveys
• Slow, high labor costs
• Work in harm’s way
• Reduced accuracy due to
low sampling density
• Low accuracy due to
inability to ‘see’ the tops,
valleys in stockpiles
Traditional Land Surveys
• Slow, high labor costs
• Work in harm’s way
• Reduced accuracy due to
inability to ‘see’ the entire
stockpile
“Holes”
Terrestrial Laser Scanning
• Major access issues
• Work in harm’s way
• Inaccurate due to
inability to ‘see’ the
entire stockpile
• Relatively expensive
“Hole”
Access - Can’t get around
many piles
Lack of access
“void”
Mobile Laser Scanning
• Can be very accurate, dense data
• Out of harm’s way
• Expensive
• Not very responsive (long lead
times, weather delays, clouds, etc)
• Huge technology/price barriers to
entry for owner/operators
Manned Aerial Survey-Photogrammetry
• Very Accurate, dense data
• Out of harm’s way
• Relatively inexpensive
• Very convenient (short
mobilization times)
• Relatively small
technology/price barriers to
entry for owner/operators
• Restricted to small areas
Unmanned Airborne Survey
small UAS technology
sUAS → mass < 55 lbs
Micro-GPS
Receivers
Light weight high
capacity Batteries
Small Hi-
Res
Cameras
MEMS
IMUs/gyros
Enabling technologies
Typical Camera Choices
Video
Inspection
Quality B
3D Mapping
Quality C
Orthos
Quality A
3D Mapping
Imaging Payloads
Canon S100
12 MP
Horizontal RMSE =
6.4 cm
Vertical RMSE =
14.0 cm
Sony NEX-5
16 MP
Horizontal RMSE =
1.3 cm
Vertical RMSE =
1.9 cm
Does camera choice effect accuracy?
Camera Sensor Dimensions
(mm)
Rows x Columns (pixels) Pixel Area (μm2)
Canon S100 7.5 x 5.5 4000 x 3000 (12MP) 3.4
NEX-5R 23.4 x 15.6 4912 x 3264 (16MP) 28.8
The light collected is proportional to the sensor pixel area. Note
that the NEX has 8 ½ times the area of the Canon – this is a huge
difference!
Photon noise varies as the square root of the image signal, so
collecting more light results in proportionally less noise, i.e. a
higher signal-to-noise ratio is achieved.
Higher signal-to-noise means more sensitivity to low-light
situations, and broader dynamic range.
Sensor Size vs. image noise
Significant
Noise
Poor Conformance
Noise from Cannon S100 images
Image Noise
Noise from NEX-5R Images
Low
Noise
High Conformance
Image Noise
Focal length is highly
correlated with vertical scale
and accuracy
Precise focal length cannot be
established for zoom lenses,
even if the zoom feature is
disabled.
Focal length calibration
• Consumer cameras do not have a Mid-Exposure Pulse
(MEP)o Real Time Kinematic GNSS
o One must know the exact correlation of each photo center to the GNSS position at
time of exposure
o Common practice is to use the camera flash signal to create a MEP with
modifications to the electronic circuitry
• Consumer cameras do not offer stock fixed focus lens
optionso Requires special lenses (which are expensive or not available for many consumer
cameras.)
Other Issues….
LIDAR
Now available for sUAS
Chock full of noise …
Low end systems need work!
LIDAR Data Set
Significant vegetation penetration
LIDAR Required for Vegetation Penetration
WorkFlow
Fly, QC,
re-fly
Georeferencing Stereo
Images
Analyze, Map
Plan
small Unmanned Aircraft Systems
Mission
Planning
Ground Control
Planning
Establish
Control/Check/
Base Station
Workflow
Fly Field Check
Georeference
Photos
Create a
“block”
Add GCPs/
Process RTKQC
Generate Point
Cloud,
Orthomosaic
Load into
exploitation
software
Test Horizontal
& Vertical
Accuracy
Product
Creation
Generate
DEM
Generate
Contours
Volumetric
Analysis
Cross
Sections
Other
Products
Workflow (cont)
Ground control for accuracy
Controlling, Checking
Good control to the airborne GPS data…
Local,
permanent
base
Temporary
base station
Virtual
Reference
System
NGS, other
CORS
RTK/PPK Reference Options
Corona Calibration Target –
W Arica Rd & Peart Rd, Casa
Grande, AZ
Semi-permanent target,
sand mine near Memphis,
TN
Verification is always necessary
Defining the Project Area
Defining and planning the Flight
Upload Flight Plan to UAS
Flight Execution
Download Flight Data for Processing
Mission
Planning
Ground Control
Planning
Establish
Control/Check/
Base Station
Workflow – Imaging/Data Processing
Fly Field Check “Align” Photos
Add GCPs/
Process RTKQC
Generate Point
Cloud,
Orthomosaic
Remarkably Good Results
data processing
using the science of
Photogrammetry
Remote Photogrammetry
”The science or art of obtaining reliable
measurements by means of photographs.”
”Photogrammetry is the art, science, and
technology of obtaining reliable information
about physical objects and the environment
through the processes of recording, measuring,
and interpreting photographic images.”
(ASPRS, 1980)
Definitions:
Analog Photogrammetry
Using optical/mechanical/electrical instruments, to perform measurements from images printed on paper, film or glass, thus creating stereographic views of the image space for the purpose of 3D measurements.
Analytical Photogrammetry
Using equipment similar to those used in analog photogrammetry but which have computer/electronic components added for more efficient measurement of photographic images. Computer software programs are also a key element in these operations.
Digital or Softcopy Photogrammetry
The performance of photogrammetric operations using digital rather than hardcopy images. This work is accomplished primarily using computer, monitors, and a specially designed mouse along with sophisticated software.
Definitions:
History
Origins of Remote Sensing
First photographs taken in 1839
Remote sensing began withaerial photography
A brief history of Photogrammetry
1858 Gasper Felix Tournachon "Nadar" takes photograph of village of Petit Bicetre in France from
a balloon.
Paris by Nadar, circa 1858
A brief history of Photogrammetry
City of Boston by Black and King (1860), from hot air balloon
A brief history of Photogrammetry
A brief history of Photogrammetry
Major developments in aerial photography – WW1
A brief history of Photogrammetry
After the war the technology was in place to begin large scale aerial surveys
A brief history of Photogrammetry
Photogrammetric Fundamentals
First Assumption: the photo image is a flat planar surface
Second Assumption: There are planar distortions in all photo images:
- Distortions come from two sources
1) the camera platten for film or the CCD platten for
digital images
2) the camera lens(s)
Photogrammetric Fundamentals
Photo Orientation
Six positions of orientation are needed to georeference each photo
Ω Omega – Yaw Φ Phi – Pitch Κ Kappa - Roll
x – Longitude y – Latitude Z - Elevation
Known constants and variables…..
Precisely controlled image capture…..
Precisely controlled image capture…..
•Over lap about 60%
Aerial Photography -Stereo pair
•Over lap about 60%
Precisely controlled image capture…..
Types of Photogrametry
Photogrammetric Types from Applications Point of
View (d is distance from camera to object)
▪ Close Range Photogrammetry d<50 m
▪ Aerial Photogrammetry 50m>d<15km
▪ Space Photogrammetry d = 300 km+
Photogrammetric Types
Close Range (terrestrial) Photogrammetry
Close Range (terrestrial) Photogrammetry
Aerial Photogrammetry
Space Photogrammetry
❖ Extraterrestrial pictures taken from space-based cameras
Types of Images
• Panchromatic, Black & White, Grayscale
• Color - Red Green Blue (RGB)
• Multispectral (RGB + Infrared)
• Hyperspectral
Introduction
Types of photographs (categorized by tilt)
• Vertical - camera axis as nearly vertical as Possible
• Oblique - camera axis intentionally tilted• Low Oblique
• High Oblique
Types of photographs (categorized by tilt)
Vertical - Aerial Photo
❖Mainly used for mapping
Low oblique (no horizon)
❖Seldom used for mapping
Low Oblique – Aerial Photo
• Horizon line in the
photo
• Typically used for
3D city modeling
High Oblique – Aerial Photo
• Maps are based on parallel projection while photo has central projection
• Maps have a unique scale. Photo scale varies depending on terrain relief and degree of radial distortion
Characteristic of a Map vs a Photo
Aerial images are not maps!
Image Acquisition for photogrammetric mapping
• Photos taken in parallel flight strips
Image Acquisition
• Each successive photograph overlap previous photo
Image Acquisition
Full Ground Control vs. Aero-triangulation
Types of Stereo Model control layout
Full Stereo Model
Control
Stereo Model Control for
Aero-triangulation
Ground Control Point Planning
Types of Ground Control Points
Types of Stereo Model control layout
Full Stereo Model Control – with Aero-triangulation
Aero-Triangulation - (georeferencing all images for a unified
block of ground control positions and tie points)
Types of Stereo Model control layout
Photogrammetric Instruments
• MULTIPLEX MODEL SKETCH
Direct Optical Projection Stereo plotters
Kelsh – Optical/ Mechanical Stereoplotter
1930s to 1970s
Direct Optical Projection Stereo plotters
Wild Heerbrugg A8–Analogue Optical Mechanical Stereoplotter
1960s to 1980s
Direct Optical Projection Stereo plotters
• Wild BC2 analytical stereo-plotter.
Analytical Optical/Electronic Stereoplotter
1980s – 1990s
Direct Optical Projection Stereo plotters
Digital Softcopy Stereoplotter
1990s - Present
Softcopy (digital) Stereo plotters
Wild C2 - 1927
Wild RC5 - 1944
Wild RC30 & Zeiss TOP15 – 1980s
3D Aerial Film Cameras
• Airborne Imagery Cameras - Manned Aircraft:
• Large Format
• Medium Format
• Small Format
RGB and IR≥200 MP
RGB or IR60 - 100 MP
RGB or IR10 – 20 MP
3D Stereo Digital Imaging Cameras
• Airborne LIDAR: Manned Aircraft
Wide Area Mapping500-800 kHz pulse
rate
Corridor Mapping200-500 kHz pulse
rate
OR
3D LIDAR Scanning
• Airborne LIDAR: Unmanned Aircraft
3D LIDAR Scanning
• Airborne Imaging & LIDAR: Unmanned Aircraft
High Quality Photogrammetric Mapping – Calibrated Lens Distortion, Mid-
Exposure Pulse, Fixed Focal Length
Medium Quality – Photogrammetric Mapping, Lens characterization, no MEP
Imaging only, no photogrammetric mapping, no lens correction
3D LIDAR Scanning plus Imaging
UAS Survey GNSS Survey Comments
Area 1.5 km2 1.5 km2
Ground control setup &
measurement
1 ¼ hr --- Ground control not required
for all applications
Setup time 15 min 15 min (per day)
Survey time 45 min 30 ½ hr (4 days)
Tear-down time 15 min 15 min (per day)
Data processing time 4 hrs
(2.80 GHz Intel Core i7,
16 GB RAM)
--- Data can be processed
overnight
Total time 6 hr 30 min 32 hr 30 min 5x faster than GNSS
Measurement sampling Distance 3.8 cm (at 120 m flight
altitude)
15 m Minimum sampling size is 2.4
cm
Horizontal accuracy 2 cm 1 cm
Vertical accuracy 4 cm 2 cm
Land Survey vs. UAS Survey Example
Surface model generated from UAS
survey (± 300,000 measurements)
Surface model generated from GNSS
survey (±1,000 measurements)
Topographic Survey Comparison
Project Project
Number
ofGSD AREA #GCPs Software PROCESSING RMSE
TYPE LOCATION IMAGESper pixel Covered
VERSION TIME³ X, Y Z
Mining Canada 185 4.4 cm 0.26 km² 8 PhotoScan Pro 2 hr 4.0 cm 10.3 cm
Forestry Alaska 372 5.2 cm 0.83 km² 11 Pix4UAV 6 hr 3.4 cm 4.2 cm
Test field Belgium 400 4.6 cm 0.84 km² 8Stretchout™ 20 min 6.4 cm 12.0 cm
Pix4UAV 5 hr 1.6 cm 3.0 cm
Mining USA 640 5.5 cm 1.2 km² 5 Pix4UAV 10 hr 1.9 cm 3.7 cm
River Bank Spain 2504 8.1 cm 13.1 km² 27 Cloud 48 hr 4.5 cm 9.5 cm
Golf Course Switzerland 510 13 cm 2.5 km² 8 PhotoScan Pro 4 hr 9.2 cm 27.4 cm
Accuracy Comparisons
• Engineering & Surveying
• Mining
• Civil & Heavy Earthworks Construction
• Oil & Gas
• Environmental & Landfill
• Public Agencies
• Agriculture & Forestry
Target Markets
Some Things to consider:
• Do you really need a UAS? • Be sure you really know why you want a UAS
• Know what kind of work you expect to do and what types of deliverables
you plan to produce
• Some common applications– Construction management
– Open pit mining
– Stock pile inventory
– Landfill management
– Bridge inspection
– Environmental monitoring
– Transmission line inspection
Before purchasing your UAS
Some Things to consider:
• What is your budget for the system?
A Rough Estimate of 1st year costs:• Equipment/SW Cost: $60K – $150K
• Pilot Salary: $40K - $100K
• Regulatory Cost: $5K - $10K
• Annual Maintenance: $10K - $25K
• Total 1st year start up: $115K - $285K
Before purchasing your UAS
Some things to consider:
• Will you need to hire additional staff?
• The typical sUAS crew for mapping & survey work consists of:
• Pilot in Charge (operator)
• Observer(s)
• Land Surveyor
• Image/data processing specialist
• Do your people have the right skills?
• Aviation training (FAA Remote Pilot minimum) for pilot and
observer
• Land Surveyor with general surveying experience and standard
equipment for establishing ground control points
• Remote Pilot and/or observer needs to have professional
photographic skills
Before purchasing your UAS
• Will work for minimum wage?
• Likes to party?
• Has medical marijuana card or
is using other non-FAA
approved medications/drugs?
• Has high score in Grand Theft
Auto?
• Family relative of the owner?
• Felony or DUI conviction?
• Poor decision making skills?
• Lot’s of life drama?
Does this describe your UAS pilot?
✓ Can study for and pass FAA
Exam.
✓ Has good vision.
✓ Has good life/work skills.
✓ VERY safety conscious.
✓ Actively improves proficiency
✓ Maintains FAA currency.
✓ Clean criminal / DUI history
Professional UAS Pilot Checklist
✓ Will not override the pilot’s
fly/no-fly decisions.
✓ Will not pressure pilot because
of deadline, client importance,
weather, etc.
✓ Will support pilot in increasing
proficiency, and maintaining
currency.
✓ Will establish, follow, and
enforce company safety policy
and all FAA rules.
✓ Invests in dedicated UAS staff.
UAS Manager Checklist
Some things to consider:
• Training needed for your UAS team
• Pilot in Charge –
• FAA operator’s course and exam
• Learn basics of aviation, air space regulations,
navigational charts, aviation weather, etc.
• UAS Manufacturer’s training
• Operations and maintenance of aircraft systems
• Aircraft safety and operations manual and training
• Detailed understanding of aerial photography techniques
• Plenty of practice with the onboard camera
• Understanding of lighting conditions and camera
settings
• Learning flight characteristics of each UAS
Before your new UAS arrives
Some things to consider:
• Training needed for your UAS team (cont.)
• Flight Observer
• FAA operator’s course and exam
• Should also be trained in system maintenance
• Land Surveyor with experience in setting ground control for
aerial photography
• Image/Data processing specialist
• Knowledge and experience with each of the various
software suites for the UAS and the final products
• Knowledge and experience preparing flight plans
Before your new UAS arrives
Some more things to consider:
• Facilities for your UAS operations.
• Secure storage for UAS system
• Space for layout, set-up, and repair work
• Vehicle for transport to job sites
• Should be large enough for equipment and crew
Including:
• 2-4 people
• The UAS with its many components
• Surveying equipment
• Launcher
• Misc. tools
• Etc.
Before your new UAS arrives
• Multiple platforms may be
necessary for multiple
mission profiles (rotor wing /
fixed wing,)
• Multiple sensors / lenses may
be necessary for multiple
mission profiles (high res /
long focal length, low res
short focal length)
• The more flexible the aircraft
and sensors, the more
mission profiles available. >
ROI
Aircraft and Sensor Considerations
• We have a confluence of new enabling technology for direct 3D modeling from sUAS platforms, is this the time for you to start using this technology?
• Sweet spot will be where the cost ground survey and flying full scale manned aircraft is too high, but UAS will work.
• Will the business paradigm shift? – will owners of mines, farms, etc. want operate their own sUAS? Will they hire you?
• Where do owners of traditional Aerial Mapping companies fit?
• Will regulations ever catch up to the advances in technology? Example… UAS can fly much higher than 400ft.
Summary & Lingering Questions
Questions