FREE 1 HOUR DRONE SURVEY MASTER COURSE

Drone Surveying Crash Course Overview

Introduction to Drone Surveying

• In this crash course, the presenter will cover essential topics related to drone surveying, including selecting the right drone, establishing survey control, planning missions, processing data with photogrammetry software, and assessing data accuracy.

• The instructor, Rammy Tamimi, is a professional surveyor and UAS pilot since 2017. He has received accolades such as the younger geospatial professional award at Geo Week 2022.

Importance of Community Learning

• Rammy runs a premium community called "the survey school," where professionals from various fields learn about surveying principles and their application in geospatial technology.

• Viewers are encouraged to focus on the content and take notes. A special offer for a free license of Pix4Datic software and an IMLid Reach GNSS receiver will be revealed at the end.

FAA Regulations for Drone Surveying

Licensing Requirements

• To conduct drone surveying legally in the U.S., obtaining an FAA Part 107 license is mandatory for all commercial operations.

• Survey companies may seek contractors who understand drone surveying if they lack in-house pilots.

Choosing the Right Drone for Surveying

Entry-Level Drones

• For beginners on a budget, drones like Phantom 4 or Mavic 2 are recommended due to their affordability and decent camera quality.

• These entry-level drones have limitations such as linear rolling shutters that can affect image quality; slower flight speeds are advised when using them.

Intermediate Drones

• The Mavic 3 Enterprise is suggested as an intermediate option under $10,000. It features a mechanical shutter camera which enhances image quality during surveys.

Mechanical vs. Rolling Shutter Cameras

• A mechanical global shutter captures images simultaneously across the scene while rolling shutters capture images sequentially leading to potential motion blur—critical for high-quality surveying work.

Advanced Drone Options

High-End Drones

• Advanced models like DJI Matrice 350 RTK and Wingra 1 Gen 2 range from $30k to $100k. They allow payload customization with interchangeable sensors (e.g., LIDAR, multispectral).

Benefits of RTK Technology

• The Mavic 3 Enterprise's RTK antenna provides centimeter-level accuracy by correcting GPS positions in real-time—essential for precise data collection in surveying tasks.

Understanding Photogrammetry

Basics of Photogrammetry

• Photogrammetry uses multiple images taken from different angles to create accurate 3D models by reconstructing scenes based on focal points.

Importance of Image Quality

• Clear imagery is crucial for effective photogrammetric processing; poor image quality can lead to inaccurate model generation.

Understanding GNSS and RTK for Accurate Data Collection

Georeferencing and GPS vs. GNSS

• Georeferencing is crucial for relating data models to specific locations on Earth, utilizing GPS information during data collection.

• GPS (Global Positioning System) is the American satellite constellation, while GNSS (Global Navigation Satellite Systems) encompasses various global satellite systems, including GPS.

• Major components of GNSS include the Russian GLONASS, European Galileo, and Chinese BeiDou systems, all contributing to global positioning accuracy.

Achieving Centimeter-Level Accuracy with RTK

• RTK (Real-Time Kinematic) corrections require three segments: space segment (satellites), control segment (base station), and user segment (GNSS receiver).

• The control segment observes satellites from a known location to correct positional errors sent to the user segment for enhanced accuracy.

• Both base stations and rovers must have clear visibility of satellites for fixed solutions; otherwise, inaccuracies arise with float or single solutions.

Ground Control Points vs. Checkpoints

• Ground Control Points (GCPs), marked by high contrast targets, enhance drone survey accuracy by providing precise coordinates for georeferencing.

• GCP identification involves selecting target pixels in photogrammetry software to ensure accurate mapping of aerial images.

• Checkpoints validate data accuracy without influencing it; they are used post-survey to compare results against measured coordinates.

Recommended Equipment for Surveying

• The Imlid Reach RS3 is recommended for beginners due to its affordability and user-friendly interface; it provides high accuracy under $3,000.

• Advanced surveyors may prefer brands like Leica Geo Systems; however, Imlid offers a solid entry point into drone surveying.

Importance of Proper Rod Handling

• Correct rod handling ensures accurate data collection; the Imlid Reach RS3 features an Inertial Measurement Unit (IMU), allowing flexibility in rod positioning while maintaining precision.

Introduction to GNSS and RTK Corrections

User-Friendly GNSS Receiver

• The GNSS receiver is designed for ease of use, allowing users to accurately collect data by correcting the position based on how the rod is held.

Cost Considerations and Alternatives

• While a single GNSS receiver costs under $3,000, purchasing two would total $6,000. However, there are alternatives for achieving centimeter-level accuracy without needing a second receiver.

ENTRIP: A Network Solution

• Introduction of ENTRIP (transport of RTCM via internet protocol), which connects rovers like drones to receive RTK corrections through a network solution.

VRS vs. CORORS Networks

• Explanation of Virtual Reference System (VRS) that uses multiple base stations versus CORORS networks that rely on physical base stations set up by municipalities or private entities.

Establishing Ground Control Points

Setting Up Ground Control Points

• The process begins with establishing ground control points using the IMLID Reach RS3 in a designated survey area depicted in Google Earth.

Initial Point Setup

• The first ground control point is set at the northeast corner of the site using five targets for accurate placement.

Using IMLID Flow App

Connecting the GNSS Receiver

• The IMLID Flow app is utilized for connecting to the GNSS receiver; it can be downloaded for free without requiring a subscription to Survey Plus.

Connection Methods

• Users can connect via Wi-Fi hotspot or Bluetooth; Bluetooth is preferred for its reliability during data collection.

Receiving RTK Corrections

Inputting Correction Types

• To obtain RTK corrections, users must select their correction input method; options include using a base station or connecting through ENTRIP over Bluetooth.

Selecting State Network

• In Michigan, users connect to the Michigan CORORS network to receive necessary corrections from local stations.

Creating and Managing Survey Projects

Starting a New Project

• A new project titled "drone survey" is created within IMLID Flow, emphasizing correct coordinate system selection based on location specifics in Michigan.

Measurement Process

• Users are encouraged to take multiple measurements (10 shots recommended per point) to ensure accuracy when measuring each ground control point.

Finalizing Ground Control Points

Completing Measurements

• After successfully measuring initial points, additional ground control points are established throughout the park while ensuring optimal satellite coverage.

This structured approach provides clarity on key concepts related to GNSS technology and practical applications in surveying with drones.

Drone Survey Preparation and PPK Corrections

Setting Up Ground Control Points and Checkpoints

• The speaker sets five ground control points and two checkpoints, marking the first checkpoint as point number six.

• The second checkpoint is designated as point number seven, completing the collection of necessary points for the drone survey.

Understanding PPK Corrections

• PPK (Post-Processing Kinematic) is introduced as an alternative to RTK (Real-Time Kinematic), which can suffer from connection issues affecting accuracy.

• A base station is set up over a known point provided by the National Geodetic Survey (NGS), ensuring reliable data correction post-survey.

• PPK does not require an internet connection; it allows for centimeter-level accuracy using just one known reference point, even if disconnected from the rover.

Utilizing IMLID Software for Data Correction

• The speaker mentions IMLID Studio software, which will be used later in the office to perform PPK corrections on collected data.

Base Station Setup Process

• The setup involves leveling a tri-bracket over the NGS monument to ensure accurate positioning of the base station.

• Height measurement between the monument and base station is taken at 151.8 cm before attaching the base station.

Configuring Drone Settings for Surveying

• After setting up, raw data logging begins through IMLid Flow software to collect observation files needed after flying.

Preparing Drone Flight Mission

• The Mavic 3 Enterprise drone is powered on along with its controller to prepare for flight mission setup using DJI Pilot 2 app.

• A polygon route is created within the app to define the survey area, allowing adjustments based on desired coverage.

Finalizing Flight Parameters

• Flight altitude is set at approximately 150 ft with side lap and overlap adjusted to 80% for optimal image capture during flight.

• Discussion about scaling projects indicates that larger areas (200+ acres) can also be effectively managed using drones.

Drone Survey Setup and Flight Process

Initial Camera Settings

• The presenter checks the camera settings, ensuring the shutter speed is set to 1/1000.

• Focus method is confirmed as AFS (Automatic Focus Center), and the camera mode is set to S for shutter priority.

• Aspect ratio is adjusted to 4:3, with image export format set to JPEG. Additional settings include enabling locked gimbal while shooting, mechanical shutter, and dewarping.

RTK Connection and Flight Preparation

• The presenter verifies that RTK (Real-Time Kinematic) positioning is active, confirming a fixed reading from Michigan.

• A base station has been established at the site for PPK (Post-Processed Kinematic) corrections in case of RTK disconnection during flight.

Autonomous Flight Execution

• The drone takes off autonomously after uploading the flight mission; monitoring by the pilot ensures everything operates smoothly.

• The drone's strong RTK signal indicates good connectivity as it completes its mission loop over the designated area.

Data Collection Insights

• As the drone approaches completion of its flight path, clear imagery captures targets effectively; overlap was intentionally designed for comprehensive data collection.

• Upon finishing its mission, the drone begins its descent back to the launch point.

Post-flight Procedures

• After landing, logging into the base station allows stopping data collection; logs are processed for post-processing kinematic corrections on collected imagery.

Upcoming Survey Research Symposium

Event Overview

• Announcement of a free survey research symposium hosted by Survey School on August 8th, 2025, featuring various research presentations related to surveying accuracy under different conditions.

Competition Details

• Presentations will cover topics such as GNSS correction accuracy and challenges faced by young professionals entering surveying.

• A competition aspect allows audience voting on presentations; winners receive a trip to Intergeo 2025 in Frankfurt sponsored by Intergeo.

Opportunities for Students

• Highlighting scholarships available through Survey School for conferences; six members were funded in the past year to attend similar events.

How to Process Drone Data for High-Accuracy Deliverables

Introduction to Data Processing

• The course will conclude with instructions on obtaining a free IML Reach GNSS receiver and Pix4D MATIC software.

• Emphasizes the importance of inputting collected drone data into a computer for processing, generating outputs, and creating deliverables.

Preparing Data for Processing

• Start by removing the SD card from the Mavic 3 Enterprise drone to access images.

• Import data using an SD card reader or directly through a desktop's SD slot; ensure you have Rhinax observation files from the base station for PPK corrections.

• A coordinate file for ground control points is essential; recommends using IMLID devices due to their compatibility with Flow 360 project management software.

Utilizing IMLID Flow 360

• Flow 360 allows real-time data transfer from mobile devices to computers without manual sending.

• Users can export CSV files containing control points necessary for photogrammetry processing; options vary based on subscription level (free vs. paid).

Exporting Control Points

• Important columns to export include name, northing, easting, elevation, lateral RMS, elevation RMS, and code.

• After exporting control points, users will have folders containing drone images and Rhinax data ready for further processing.

Introduction to IMLID Studio

• IMLID Studio is available for free and allows updating geo-tag locations of images using PPK corrections.

• Users must select the appropriate observation files from both drone image folders and reach base folders during setup.

Finalizing Data Alignment

• Input latitude, longitude, ellipsoid height of occupied points along with base station height into IMLID Studio.

• Upload navigation files and MRK files that align images with drone positions ensuring accurate temporal resolution during processing.

Processing Results

• Upon processing in IMLID Studio, users can expect high success rates in fixed readings using PPK corrections.

PPK Correction and Data Processing Steps

Understanding PPK Correction Benefits

• The fixed PPK correction provides a sense of relief, ensuring all images have high centimeter-level accuracy.

• It is recommended to export new images instead of updating original photos to maintain an archive for future reference.

Exporting and Tagging Images

• Users can compare datasets from older drones without RTK against those with RTK for statistical analysis.

• The next software introduced is Pix 4D Matic, known for its user-friendly interface and robust photogrammetry processing capabilities.

Setting Up the Project in Pix 4D Matic

• A new project titled "drone survey" is created, setting the coordinate system to match ground control points (NAD83 Michigan South and NAVD88).

• Images are dragged and dropped into the project; blue dots indicate uncalibrated camera positions that will be calibrated later.

Importing Ground Control Points

• Ground control points measured with a rover are imported to enhance dataset accuracy.

• Each point must be geo-referenced by selecting their center in multiple images, although not all images need referencing.

Geo-referencing Process

• Attention should be paid to ensure correct targets are selected during geo-referencing; contrast between colors aids visibility.

• Checkpoints do not influence data accuracy but serve as validation points after processing with ground control points.

Calibration and Model Generation

• After geo-referencing, users can calibrate data to generate an initial photogrammetric 3D model. Calibration duration varies based on project size.

Calibration and Processing of Drone Survey Data

Calibration Results

• The calibration process is complete, showing calibrated camera positions as green dots in Pix 4D Matic, slightly shifted from initial positions.

• Ground control points have an RMSSE of 0.047 and checkpoints at 0.049, indicating high accuracy within 2 cm or less.

Ensuring High Accuracy

• High accuracy is achieved through the use of RTK corrections for drone trajectories and PPK corrections for accurate geo-tagging of images.

• The next step involves processing outputs like point clouds, mesh files, DSM (Digital Surface Model), and ortho images.

Output Analysis

• Outputs include a DSM representing elevation maps and a high-resolution ortho image that allows significant zooming without loss of clarity.

• Using a mechanical shutter camera results in crisp imagery; hundreds to thousands of images contribute to generating a detailed orthomosaic.

Importance of 3D Point Clouds

• A well-rendered 3D point cloud provides an immersive reconstruction of the surveyed area, enhancing the value beyond traditional images or videos.

• While visually appealing, these outputs are not the final deliverables expected by clients.

Transforming Data into Valuable Information

Understanding Client Needs

• Clients seek valuable information rather than raw data; understanding this distinction is crucial for delivering what they need.

• Extracting meaningful insights from data will differentiate service providers in the competitive drone surveying market.

Essential Software Tools

• Introduction to two additional software tools necessary for transforming data into valuable deliverables: Pix 4D Survey as an extension of Pix 4D Matic.

Simplifying Data Sets

• Pix 4D Survey simplifies complex datasets with millions of points into manageable formats while retaining essential information.

Integration Process

• Users can easily transfer data from Pix 4D Matic to Pix 4D Survey by selecting "open in Pix 4D survey," facilitating further analysis and output extraction.

Terrain Classification and Feature Extraction in Pix4D

Distant Outlier Filter and Terrain Definition

• The process begins with applying the distant outlier filter to clean up the drawing by removing unwanted data points.

• The terrain classification identifies ground elements while declassifying man-made objects and vegetation, marking them as non-terrain (shown in purple).

Digital Elevation Model (DEM)

• A digital elevation model (DEM) consists of evenly spaced points that represent terrain, reducing data volume without losing accuracy.

• It is crucial to select only the terrain filter when creating a DEM to ensure accurate representation of ground features.

Grid Creation and Point Selection

• The low pass filter is recommended for selecting the lowest point in an area, which accurately represents true ground level.

• By generating a grid with 9,000 DEM points instead of 10 million terrain points, data management becomes significantly more efficient.

Feature Extraction Process

• Feature extraction identifies significant elements like sidewalks and curbs within the dataset using Pix4D Survey's tools.

• New layers can be created for different features; for example, a "back of curb" layer can be added and colored red.

Layering Features on Point Cloud

• Points are selected along the curb using polyline options to create an accurate virtual survey similar to traditional methods.

• Additional layers such as gutter lines (green), center lines of roads, and concrete areas are mapped out systematically based on visual cues from point clouds.

Material Identification

• If uncertain about material types during mapping, aerial images can assist in identifying materials like concrete or asphalt.

• A new layer labeled "asphalt" is created for sidewalks after confirming material type through image analysis.

This structured approach allows for effective surveying using advanced software tools while ensuring clarity in data representation.

Feature Extraction and TIN Generation Process

Extracting Terrain Features

• The process begins with extracting the sidewalk, ensuring that it follows the true path as validated by images.

• Non-terrain points such as trees, fences, and utility poles are also important to include in the feature extraction.

• A point cloud is utilized to visualize non-terrain objects while turning off the terrain layer for clarity.

• Utility features are identified and labeled, including utility poles and an electric box, enhancing data organization.

• A new layer for trees is created, allowing for easy identification of tree locations on or around the property.

Identifying Trees and Fences

• Multiple trees are marked individually based on their positions rather than elevation, focusing on accurate placement.

• Tree lines along property boundaries are drawn using polylines to simplify representation without detailing every single tree.

• The process involves clicking along edges to define where tree lines exist, making it efficient to map out these features.

• A final layer for fences is added; points are placed at key locations to outline fence structures clearly.

• The extraction process remains simple yet effective by avoiding excessive detail about neighboring properties.

Generating a Triangular Irregular Network (TIN)

• After completing feature extractions, a TIN is generated which creates a surface model from all extracted points and line work.

• Important settings include enabling terrain layers as break lines before generating the TIN model for accuracy in representation.

• The resulting TIN model displays various features like curb lines and sidewalks clearly, aiding in visual analysis of the area.

Visualizing Contours

• One-foot contour lines are generated from the TIN model to help visualize terrain elevations effectively.

• This visualization assists in understanding water flow directions based on road placements and surrounding topography.

Drone Surveying and Data Export Process

Understanding Terrain Visualization

• The speaker discusses the importance of visualizing terrain by turning off non-terrain points to better understand ground elevation and creek locations.

• A specific drop point is identified where the creek flows, emphasizing the significance of understanding water flow in surveying.

Data vs. Information

• The distinction between data and information is highlighted, with a focus on how this information will be presented to clients.

• The final step involves exporting data into AutoCAD Civil 3D, an industry-standard software crucial for effective surveying.

Exporting Data to AutoCAD

• It is recommended to export all data as a DXF file format for compatibility with AutoCAD Civil 3D.

• The process of importing various elements such as contour lines and grid points into AutoCAD is described, showcasing the integration of different data types.

Deliverables from Drone Surveying

• The speaker mentions that combining extracted data with high-resolution ortho images creates valuable deliverables that can command high fees in the market.

Educational Resources and Community Support

• Free access to Pix4D Matic software and IMLD Reach GNSS receivers is offered as part of community support for students in the Survey School.

• The Survey School operates on a leveling system that rewards active members with access to additional resources like courses, software, hardware, and grants for conferences.

Commitment to Learning in Surveying

• Emphasis is placed on motivation within the community; committed members receive support from sponsors like IMLD and Pix40 for hands-on training opportunities.

• A call-to-action encourages viewers to explore more resources at surveyschool.com and consider joining the Survey School for further education in surveying.