steve zeets, ps faa licensed pilot tm...• sony a6000 aps-c exmor hd cmos sensor, 24.3mp, 6000x4000...

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www.whirrx.com

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Survey Faster. Survey Better.TM

TM

Steve Zeets, PSFAA Licensed Pilot

How to Ensure Accuracyin your Drone Data

www.whirrx.com

2Agenda

• My Background & Experience with Drones

• How to Operate a Commercial Drone Legally

• Choosing a Drone Type that’s best for your Use Case

• Drone Photogrammmetry

• Setting Proper Survey Control

• Achieving and Verifying Desired Data Accuracy

• Things to Consider When Choosing a Survey Grade Drone System

• Other things to consider…

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3My Background

• Rodman on 3-man Survey Crew - 1996

• Small Civil Engineering/Surveying firm

• Started Using RTK GPS - 1997

• Civil CAD Designer - 1999

• IT Duties and Building Custom Computers - 2000

• Started Using GIS - 2001

• Received Professional Surveyor License - 2007

• Started Using Photogrammetry – 2008

• Jeff Walsh

• Manned Aircraft

• Airport Obstruction Surveys

• High Accuracy Photogrammetry Projects

• Landfills

• Engineering Projects

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4My Experience with Drones

• My Drone “Hobby” - 2011• Read an article in Summer 2011 about an RC Multi-rotor with camera

• Found out the FAA banned commercial drone use in 2007

• Waiting for FAA rules…

• Built Quad in Fall 2011

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• Bought a Mikrokopter

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• Flew first successful mapping missions in 2012 with Mikrokopter Hexa

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• Flew many more test missions in 2012

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• Logged over 220 flights with Mikrokopter’s• Worst Ground Resolution was a little over 1-inch

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• Tested Fixed-Wing Aircraft• Chose Ritewing with Pixhawk electronics• Over 600 flights and 1000 miles of autonomous flight

lines flown with UAS from 2011-2015

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10My Background (Cont’d)

• Created UAS Company (Terraplane) in 2014

• Filed for Section 333 Exemption on September 4, 2014

• Granted Exemption on March 24, 2015

• Finished Pilot’s License in Fall 2015

• Operated Terraplane Full-Time Starting in 2016

• Flew & Processed Many Projects

• Private & Government Clients

• Many Clients we approached as Terraplane Wanted to Operate Drones In-House

• Founded Whirrx in May 2018 to Fill Large Gap in Turn-Key Drone Surveying Systems

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11How to Operate a Commercial Drone Legally

• https://www.faa.gov/uas/

• Requirements to Becoming an FAA-Certified Drone Pilot (Part 107)

- At least 16 years old

- Able to Read, Write, Speak, and understand English

- Be in a Physical and Mental condition to safely fly a UAS

- Pass Written Test

- $150 to Take Test

- 60 Test Questions; 120 minutes to complete

- 70% Correct to Pass

- Re-test Every 2-years to Stay Current

• Drone Requirements

- $5 Drone Registration

- Renew Every 3-years

- https://faadronezone.faa.gov

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12Obtaining your Part 107 Certificate

• Study https://www.faa.gov/regulations_policies/handbooks_manuals/aviation/media/remote_pilot_study_guide.pdf

- Part 107 Rules

- Airspace Charts

- Aviation Weather

- sUA Loading

- Emergency Procedures

- Crew Resource Management

- Radio Communication Procedures

- sUA Performance

- Physiological Factors Affecting Pilot Performance

- Aeronautical Decision-Making and Judgement

- Airport Operations

- Maintenance and Preflight Inspection Procedures

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13Obtaining your Part 107 Certificate

• Schedule to take the Test

• FAA-approved testing center• https://www.faa.gov/training_testing/testing/media/test_centers.pdf

• Complete Form 8710-13

• IACRA (Integrated Airman Certification and Rating Application)• https://iacra.faa.gov/IACRA/Default.aspx

• Pass Test

• Wait for TSA Background Check Email

• Print Temporary Remote Pilot Certificate

• Permanent Remote Pilot Certificate will be Mailed

• Contact Testing Center if isn’t received in 30-60 days

• Carry Remote Pilot Certificate Card Whenever Flying your UAS

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14Part 107 Rules

• Full Part 107 Rule• https://www.ecfr.gov

• AC 107-2• https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC_107-2.pdf

- Remote PIC

- Can Trade Off Control During Flight while both maintaining VLOS

- Person Manipulating the Flight Control – No Part 107

- VLOS

- May briefly lose sight of aircraft

- VO is Optional

- Operating Limitations

- 400 feet AGL Maximum

- 100 mph maximum

- Minimum Visibility of 3sm

- Flights over persons Prohibited

- Operation from Moving Vehicles Allowed over sparsely-populated areas

- Draft NPRM Part 107 – January 14, 2019 (pdf)

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15Part 107 Waivers

• Part 107 Waivers (https://faadronezone.faa.gov)

• Operational Waiver

• Operations At Night

• BVLOS

• Operations Over People

• Operating Multiple sUA

• Operating Limitations

• Faster than 100mph

• Higher than 400 feet AGL

• Airspace Authorization

• Next Pages

• Airspace Waiver

• Next Pages

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16Part 107 Waivers

• Airspace Authorization

• Airspace Maps Online – Is Authorization Needed?

• Traditional VFR Map

• https://skyvector.com/

• UAS Data Map

• https://faa.maps.arcgis.com/apps/webappviewer/index.html?id=9c2e4406710048e19806ebf6a06754ad

• LAANC (Low Altitude Authorization and Notification Capability)

• If LAANC not available yet, use https://faadronezone.faa.gov

• LAANC Software (https://www.faa.gov/uas/programs_partnerships/data_exchange/#approved)

• https://app.airmap.io/

• Airspace Waiver

• Long Term Flights

• Class E - Surface

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17Is Authorization Needed?

• https://skyvector.com/

• https://www.faa.gov/air_traffic/flight_info/aeronav/digital_products/aero_guide/media/editions/cug-complete.pdf

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18Is Authorization Needed?

• https://faa.maps.arcgis.com/apps/webappviewer/index.html?id=9c2e4406710048e19806ebf6a06754ad

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19LAANC Software

• https://app.airmap.io/

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20LAANC Not Available?

• https://faadronezone.faa.gov

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21Airspace Waiver, not Authorization?

• Class E - Surface

• https://faadronezone.faa.gov

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22Choosing a Drone Type that’s Best for Your Use Case

• Inspection or Monitoring

- Environmentally or Culturally Sensitive Areas

- Expensive or Hard to Reach Areas

- Construction Site Assessment

• Data Collection

- Surveying for Planning or Design

- Elevation Data for CAD/GIS

- Bridges, Construction Quantities, Stockpiles, Utilities

- Aerial Imagery or Mapping

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23What Type of Data is Needed?

• Just Need “Site Pictures”?

- Part 107 Pilot

- “Video Drone” - DJI Phantom or GoPro Camera

- Semi-Autonomous or Semi-Assisted flight

- Manual flight

- Typically only a few hundred feet away

• Need Accurate Data or Survey Grade Accuracy?

- Part 107 Pilot

- Larger, more Advanced Drone System

- Pre-programmed flight pattern up to 1-mile away

- Autonomous or Semi-Autonomous flight

- “Lawn-mower” pattern or Long corridor flight

- Photogrammetry Knowledge

- Sensors, Aerial Targets, Flight Planning, etc.

- Not “Push Button” Software

- Experience Post-Processing Data

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24Where did drones come from?

• Are Commercial Drones old military technology?

• Smart phone revolution started drone revolution in 2007 with iPhone

• Coincidentally, FAA Banned all Commercial Drone use in 2007

• Put electronics and sensors from smart phones into RC Planes

• Smart phones with cameras helped shrink size

• Along with consumer digital camera revolution

• Then along came multi-rotors…

• Drones started to Mature in 2014/2015

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25Types of Drones (Under 55 lbs.)

• 4 Main Categories of Drones• Multi-Rotor

• Helicopter

• Fixed-Wing

• Hybrid

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26Multi-Rotor

• Basics of Layout• Typically 3-8 Motors

• ESC’s for each motor

• Needs ‘system’ to fly level

• Sensor in front or under

• Sensor Gimbal

• Landing Gear

• Chute System

• Electric (typically)

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27Why Use a Multi-Rotor?

• Pros• VTOL

• Fixed Sensor Position

• Slow Flight for inspection

• Easy to fly

• Cons• Short flight endurance

• Range of flight

• Motor Redundancy

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28Helicopter

• Basics of Layout• Single or Coaxial rotor

• Gas or Electric

• Two motors

• Only one for lift


• Sensor Gimbal

• Landing Gear

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29Why Use a Helicopter?

• Pros• VTOL

• Heavy Payload Capable

• Good Flight Endurance

• Autorotation

• Cons• Hard to fly

• Very large (typically)

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30Fixed-Wing

• Basics of Layout• Single motor (typically)

• Single ESC

• Front or Back motor

• Gas or Electric


• Hand or Catapult Launch

• Chute System

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31Why Use a Fixed-Wing?

• Pros• Long flight endurance

• Heavy Payload Capable

• Can glide with motor out

• Cons• Launch and Recovery space

• Hard to fly

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32Hybrid

• Basics of Layout• Multiple Engines

• Needs ‘system’ to fly

• Complex flight mechanics

• Complex transition

• Gas or Electric


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33Why Use a Hybrid?

• Pros• VTOL

• Decent flight endurance

• Can glide with motor out

• Cons• Complex flight mechanics

• New to market – lots of unknowns

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34Other Things to Consider for your Drone

• Off-the-shelf Drone or Custom?

• Field Repairs?

• Modifications?

• Up-to-Date Sensors?

• Multiple Drones?

• Backup Drones?

• Battery Types

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35What is Photogrammetry?

• Photogrammety is the art, science, and technology of obtaining reliable information about physical objects and the environment, through processes of recording, measuring, and interpreting images and patterns of electromagnetic radiant energy and other phenomena.

• Remote Sensing techniques are used to gather and process information about an object without direct physical contact

• Started in WWI for reconnaissance (~Aug 1914)

• 1920’s-1930’s in U.S.

• Topography and aerial mosaics

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• American Society for Photogrammetry and Remote Sensing

• Founded in 1934

• Over 7,000 Professional Members Worldwide

• Certifications for Photogrammetry (Manned and UAS), Mapping Scientist (Remote Sensing, LiDAR)

• Council of Engineering and Scientific Specialty Boards (CESB) Accreditation

• Similar to PE & PLS• Testing Required

• Annual PDH Requirements

• Years Experience Req.

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• Aerial Sensors

• MegaPixels (MP)

• Pixel Size

• Sensor Size

• Sensor Type

• Rolling/Mechanical Shutter

• Lens

• Metric

• Non-Metric

• Focal Length

• Radial Distortion, Shorter = Worse

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38Different Camera Sensors

• DJI P4Pro (X4) 1” EXMOR R CMOS Sensor, 20MP, 8.8mm Lens, 4096x2160 pixels, Mechanical Shutter

• ~3.22 Micron Pixel Size

• Sony A6000 APS-C EXMOR HD CMOS Sensor, 24.3MP, 6000x4000 pixels, Mechanical Shutter


• Sony A7 Full-Frame EXMOR HD CMOS Sensor, 24MP, 6000x4000 pixels, Mechanical Shutter


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39Camera Sensor Type

• What is a Pixel?

• On-Chip microlens

• Colour Filter

• Sensor Aperture

• Sensor Area

• CCD vs CMOS

• CCD = Charge-Coupled Device

• Lower Price, slower shooting speed, lower resolution

• CMOS = Complimentary Metal-Oxide-Semiconductor

• Uses Less power, quicker shooting speed, 4k

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40Camera Sensor Type• Sensor Technology Improvements

• Gapless Microlens

• More light directed, less amplification needed = less noise

• Thinner Wiring Layer

• More light

• Back-lit CMOS

• Less Noise

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41Camera Sensor Size

• Pixel Size Matters

• 1” Sensor

• 2/3” Sensor

• Micro 4/3 Sensor

• APS-C Sensor

• Full-Frame Sensor

• Full-Frame Sensor Zoomed

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42Field-of-View and Footprint Size

• How Aerial Sensor and Lens Length Affect IFOV

• Different Flying Heights

• Resolution

• Overlap Coverage Area

• How Sensor Affects Flight Speed Maximum

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43Different Camera Sensors

• DJI P4Pro 1” Sensor, 20MP, 8.8mm Lens, ~3.22 Micron Pixel Size

• 100ft AGL = 150’ x 100’ @ 0.04’ (1.2cm) Resolution




• Sony A6000 APS-C Sensor, 24.3MP, 16mm Lens, ~3.92 Micron Pixel Size





• Sony A7 Full-Frame Sensor, 24MP, 24mm Lens, ~5.97 Micron Pixel Size





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44Camera Calibration• USGS – OSL (Optical Science Laboratory

• Since 1973, USGS OSL has been responsible for calibrating analog film cameras for the aerial mapping community. In 2000, they installed a digital camera calibration facility at their EROS Center in Sioux Falls, SD. On April 1, 2017 they closed the OSL and stopped calibrating analog film cameras. They have closely worked with ASPRS.

• USGS – EROS & ECCOE (EROS [Earth Resources Observation and Science] Calibration/Validation Center of Excellence)

• EROS studies land change and produce land change data products used by researchers, resource managers, and policy makers across the nation and around the world. They also operate the Landsat satellite program with NASA, and maintain the largest civilian collection of images of the Earth’s land surface in existence, including tens of millions of satellite images.

• ECCOE - Recognized nationally and internationally as a leading organization for effectively improving the accuracy, precision, and efficiency of radiometric, geometric, and spatial characterization, calibration, and cross-calibration of optical remote sensing systems to achieve the highest degree of interoperability of remote sensing data products.

• USGS – UAS NUPO (National Unmanned Aircraft Systems Project Office)

• Was established on May 8, 2008 to coordinate the adoption of UAS data collection into the scientific, monitoring, and resource management functions of the Department of the Interior (DOI)

• https://uas.usgs.gov/aboutus.shtml

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45Photogrammetry

• ASPRS Journal Articles

• Doming Issues in UAV Derived Data

• Mitigating Error Propogation in Topography Models

• Calibrating Systematic Camera Errors

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46Photogrammetry

• Aerial Control

• Surveying

• ASPRS Positional Accuracy Standards

• Target Accuracy

• Target Sizes

• Target Placement

• Accuracy Checks

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47Photogrammetry

• ASPRS Positional Accuracy Standards• (Open External pdf Document)

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48Setting Proper Survey Control

• Panels or painted?

• Location – Strength of Triangles

• Placement – Shadows, Asphalt Wheel Ruts, etc.

• Static GPS w/Static Base or Local RTK Base for Speed with Accuracy

• RTN/VRS = Unreliable vertical… possibly good horizontal

• Level for Vertical when needing less than 0.05’

• Horizontal Accuracy Matters with Photogrammetry

• Identify Sources of Horizontal Error

• Bubble, Bent Rod, Optical Plummet, etc.

• NGS RTK Surveying pdf

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49Source of Accuracy Errors

• Pole plumb, how many minute bubble level?• 40’ Bubble (Typical), 0.035’ off when at edge of circle

• Calibrate bubble level?

• Rod Run-out, typically 3mm (0.01’)

• Total Station Horizontal Accuracy over pin

• RTK Surveying Techniques

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50Achieving and Verifying Desired Data Accuracy

• Check Points should be the same level of accuracy as control points

• Check Point Locations

• Not near vegetation, joints, sharp grade changes

• Do Not Use Check Points in Photogrammetry Software, Only Ground Truth

• Data Deliverables – Include Interpolation Error

• Data Formats

• CAD

• GIS

• Etc.

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51Things to Consider When Choosing

a Survey Grade Drone System

• Software Processing Companies

• Drone Only Companies

• Etc.

• Company Backgrounds – Surveying, Remote Sensing, Photogrammetry, etc.

• White Papers – Read them!!

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52Other Things to Consider…

• All sizes and types of drones crash or Fly-Off

• They can crash or fly-off frequently

• Article in Washington Post “When Drones Fall From the Sky”

• 271 Class A, B, and C mishaps from 2011 – 2017

• Average of about 39 incidents per year

• 2015 was exceptionally bad year, with 49 mishaps

• Class A mishaps incur $2MIL or more in damages

• Class B mishaps incur $500k - $2MIL

• Class C mishaps incur $50k - $500k

• Can involve $2MIL - $4MIL drones

• AeroVironment RQ-11 Raven crash in backyard tree – May 2015

• General Atomics MQ-1C Gray Eagle crash “selfie” – July 2015

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53Other Things to Consider…

• Commercial Drones cost MUCH less than military drones

• Suffer from the same “crash syndrome”

• Safety First!

• Risk Mitigation!

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Questions?

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steve zeets, ps faa licensed pilot tm...• sony a6000 aps-c exmor hd cmos sensor, 24.3mp, 6000x4000...

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