Carry out operations with rotary-wing drones (quadcopters) for
mapping, monitoring, and inventory of marine environments on rocky shores,
using photogrammetry as the main data collection technique. The project integrates
Brazilian aviation regulations, operational safety, and field best practices.
Context and Relevance
Rocky shores are complex environments with high biodiversity and difficult terrestrial access.
Drones reduce operational risks and enable high-resolution data collection.
Brazilian regulations (DECEA/Ordinance 2.094) govern the use of RPAS (Remotely Piloted Aircraft Systems).
Photogrammetry with drones produces orthomosaics and 3D models for environmental analysis.
The project integrates pre-field, field, and post-field protocols to ensure data quality.
What Will Be Done
1️⃣ Regulatory Preparation
Compliance with DECEA regulations, obtaining authorizations, operational risk assessment (ORA), and remote pilot certification.
2️⃣ Data Collection
Photogrammetric flights over rocky shores with image overlap (80% front, 60% side) for 3D reconstruction.
3️⃣ Processing
Orthomosaics, point clouds, digital elevation models (DEM), and biological cover analysis in GIS.
4️⃣ Temporal Monitoring
Repeated campaigns in different seasons to assess seasonal changes and environmental impacts.
Questions the Project Answers
How can rocky shores be mapped safely and efficiently using drones?
What are the legal requirements for RPAS operations in coastal environments?
How can photogrammetric quality be ensured on rocky shores with complex relief?
How can changes in biological cover be monitored over time?
How can operations be carried out safely while reducing environmental risks?
💡 Key Message: Drone operations on rocky shores require technical knowledge,
regulatory rigor, and structured planning to generate quality data and ensure operational safety.
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⚖️ Legislation Applied to Drone Operations
DECEA ORDINANCE No. 2.094/DNOR8 - 03/18/2026
ICA 100-40/2026 as an Operational Reference
ICA 100-40 complements DECEA Ordinance No. 2.094/DNOR8 as a quick-reference document for framing RPAS operations, recording responsibilities, and checking operational limits before flight.
Operational ceiling: keep the 400 ft AGL limit (approx. 120 m) unless a specific authorization applies.
VLOS on rocky shores: maintain direct visual line of sight throughout the operation, with an observer when terrain or coastal fog reduces visual awareness.
Traceability: keep authorization, operational risk assessment, aircraft data, and pilot identification attached to the mission record.
Main Concepts
What is RPAS?
RPAS (Remotely Piloted Aircraft System) is a set of components that includes the unmanned aircraft,
the remote control station, communication links, and all elements needed for safe operation.
It differs from hobby aircraft because it is operated for professional purposes (mapping, monitoring, inspection).
RPAS vs Hobby Aircraft
Criterion
RPAS
Hobby Aircraft
Purpose
Professional (work, research)
Recreational
Regulation
DECEA/ANAC
DECEA (less strict)
Pilot Certification
Mandatory (course + exam)
Not mandatory
Flight Authorization
DECEA (ORA)
Simple notification
Insurance
Recommended
Optional
Access to Brazilian Airspace
Airspace Classes
RPAS operations on rocky shores take place in uncontrolled airspace
(up to 400 feet AGL). Even so, every operation must be notified to DECEA.
Advantages: Thermal, multispectral, and LiDAR cameras.
Use: Vegetation cover and thermal stress analysis.
Cameras and Sensors
Photogrammetry Specifications
Resolution: Minimum 20 MP to ensure GSD (Ground Sample Distance) < 2 cm
Sensor: Full Frame (35 mm) for better quality in adverse conditions
Lens: Fixed focal length (24 mm equivalent) for geometric consistency
Stabilization: 3-axis gimbal to reduce motion blur
Auto ISO: Important for cloudy coastal skies
Aerodynamics Technologies
Lift in Quadcopters
Quadcopters generate lift through 4 propellers. Motor speed variation
allows control of pitch (forward tilt), roll (side tilt),
yaw (vertical rotation), and throttle (altitude).
Factors That Affect Flight on Rocky Shores
Coastal Wind: Refraction and turbulence when hitting rocks. Limit to > 8 m/s
Electromagnetic Interference: Proximity to salt water. Keep 50 m away from high-voltage lines
Solar Radiation: Battery overheating on clear days. Monitor temperature
Temperature: LiPo batteries perform best between 15-25°C
Recommended Software and Applications
Flight Planning
DJI FlightPlanner: Automatic planning with configurable overlap
Pix4D Capture: Intuitive interface, integrated with photogrammetry
UGCS (Universal Ground Control): Manual and automatic control
Photogrammetric Processing
Pix4D: Industry reference for drone photogrammetry
Agisoft Metashape: Superior quality, more computing control
OpenDroneMap: Open-source software, good for studies with limited budgets
GIS Analysis
QGIS: Open-source software, excellent for orthomosaics and analysis
ArcGIS: Professional standard in environmental management
Drone2Map (Esri): Direct integration with ArcGIS
📝 Pre-Field Methodology
Critical phase in which protocols are defined, equipment is checked, and legal obligations are met.
Tip: use Ctrl+P to save as PDF after the desired tab is activated.
1. Research and Planning (2-4 weeks before)
📍 Defining the Study Area
Select rocky shores based on scientific criteria (biodiversity, accessibility, etc.)
Obtain exact GPS coordinates (WGS84, UTM zone for Brazil)
Consult tide charts (tide tables for the campaign period)
Check sunrise/sunset times (daylight operation required)
Identify restrictions: Conservation Units, private property, air exclusion zones
📋 Review of Regulations and Authorizations
DECEA: Check airspace restriction map (e-NotaM)
IBAMA/ICMBio: If in a Conservation Unit, request environmental license
Local City Hall: Check municipal restrictions
Brazilian Navy: If near military coastal facilities
Landowners: Obtain written permission for land access
🎯 Flight Plan Design
Define flight altitude (80-120 m recommended for rocky shores)
If there is a technical problem: activate RTH (Return to Home)
🛬 Landing and Shutdown
Finish the flight plan (returns automatically)
Automatic landing at the takeoff area (RTH)
If manual control is needed: descend slowly
Stop motors: switch off the remote controller after resting
Discharge the battery if the mission is over (leave 20% for the next day)
Remove the SD card carefully
3. Field Data Recording
Flight Log Sheet (essential for traceability)
Fill in after each flight:
Date/Time: Start and end of the flight
Location: Name of the shore, central coordinates
Flight Altitude: In meters above terrain
GSD Obtained: Calculated or provided by the app
No. of Photos: Captured during the flight
Coverage (%): Percentage of mapped area
Weather: Wind speed, cloud cover, visibility
Battery: % at return, temperature
Problems: Any incident (wind, signal loss, etc.)
Notes: Relevant observations
4. Safety Measures During Flight
⚠️ Emergency Protocol
Signal Loss: The drone triggers automatic RTH. Check whether it lands in the correct place
Low Battery: The app warns at 30%. RTH activates automatically
Motor Failure: The drone crashes. Isolate the area. Do not retrieve it until approval
Sudden Strong Wind: Abort the mission, activate RTH, land
Person Entering the Zone: Stop, call the person, warn them
Gimbal/Camera Failure: Abort the flight, discard data if poor quality is suspected
5. Second Flight (if needed)
Wait 10-15 min between flights (electronic cooling)
Swap the battery for a charged unit (keep it in the shade until use)
Format a new SD card
Run a new mission in a complementary area (do not repeat exactly)
Record the second flight data in the spreadsheet
6. Visual Monitoring (VLOS)
Legal Obligation: The remote pilot must keep direct visual line of sight (VLOS) with the drone throughout the flight.
Maximum recommended distance: 100-120 meters horizontally.
Use a safety observer as backup.
💾 Post-Field Methodology
Data processing, quality assurance, and production of scientific outputs.
Useful for binding into a field notebook or generating an institutional PDF.
1. Data Backup and Security (24h after fieldwork)
1
Immediate Transfer
Connect the SD card to the computer (USB-C/SD reader)
Copy the image folder to an external working SSD
Check integrity: number of files = number of photos in the flight
Repeat flights over the same shore in different seasons (quarterly/biannual)
Use the same flight parameters: altitude, GSD, overlap
Align orthomosaics in GIS (QGIS Georeferencing plugin)
Calculate coverage changes: reclassify old images with a new classifier
Multitemporal analysis: change indices (post-classification comparison)
2-3 Year Time Series
Assess seasonal trends (algae loss/gain over periods)
Detect impacts from extreme events (storms, thermal variation)
Provide baseline data for future scenario modeling
7. Data Archiving and Dissemination
Data Repository
Zenodo (CERN): Open archive with DOI, citable in publications
UFSC DataBank: If available in PPGOceano
GeoNetwork (INPE): For Brazilian geospatial data
Metadata (ISO 19115)
Title, abstract, keywords
Spatial coverage (bbox in WGS84)
Collection date, update frequency
Spatial resolution (GSD)
Reference system (EPSG:31980)
Data owner, contact
⚠️ Flight and Operational Safety
1. SIPAER System (Accident Prevention)
What is it?
SIPAER (Aeronautical Accident Investigation and Prevention System)
is the Brazilian structure for investigating air accidents. Although focused on civil aviation,
its safety principles also apply to RPAS.
SIPAER Principles
No Blame: Investigation without the goal of blaming individuals
Learning: Extract lessons from incidents to prevent repetition
Traceability: Document every event for analysis
2. Drone Risk Factors
🌪️ Weather
Risk: Wind > 10 m/s, rain, thunder.
Mitigation: Anemometer, INMET forecast, abort if gusts > 8 m/s.
🔋 Battery
Risk: Electrical failure, sudden crash.
Mitigation: Test health, charge to 100%, rest 10-15 min between flights.
📡 GPS/Radio Signal
Risk: Communication loss, uncontrolled drone.
Mitigation: RTH configured, operate away from interference sources, check satellites.
👨✈️ Human Factor
Risk: Fatigue, lack of attention, operational error.
Wind risk: Medium (typical coastal 5-7 m/s) → Abort if > 8 m/s
Water risk: High (proximity) → Floats recommended
People risk: Low (isolated area) → Confirmed; keep signage
Wildlife risk: Medium (bird breeding season) → Avoid nesting period
Equipment risk: Low (maintenance up to date) → OK for flight
Final Classification: MODERATE → Authorized with conditions
4. Emergency Protocol
Signal Loss: Drone activates RTH automatically. Monitor whether it returns to the correct place. If it does not return, document the last-known coordinates and notify DECEA.
Motor Failure: Drone crashes. DO NOT touch until fully stopped (30 sec). Photograph the site. Notify DECEA if the crash is near people/property.
In-Flight Collision: Drone damaged or crash. Stop the mission immediately. Provide first aid if a person is hit (rare, since the flight is in an isolated area).
Battery Fire: Swollen battery or crash = potential fire. Use a CO2 extinguisher if available. Keep people 10 m away. DO NOT use water.
Person Entering the Zone: Call them to stop. Pause the flight. Warn them about the risk. Resume only with approval.
5. Maintenance and Equipment Integrity
Routine Calibration
Compass: Every 5 flights or when changing location (> 100 km)
IMU (Inertial): Every 10 flights or if behavior is anomalous
Camera: Manual white balance for every field campaign
Gimbal: Axis calibration monthly
Component Replacement
Propellers: Every 50 flight hours or annually (natural wear)
Annual Refresher: CORPAS theoretical course (certificate valid for 3 years)
Documentation: Keep records of all flights, incidents, and maintenance
📚 Technical Glossary
RPAS (Remotely Piloted Aircraft System)
Remotely piloted aircraft system; includes the drone, control, communication, and operator.
DECEA (Department of Airspace Control)
Brazilian agency responsible for airspace regulation and control, including RPAS.
ANAC (National Civil Aviation Agency)
Brazilian civil aviation regulatory agency; certifies aircraft and pilots.
ORA (Operational Risk Assessment)
Systematic analysis of RPAS operation risk; mandatory according to SANAC 93-001.
ICA 100-40
Brazilian Aeronautics Command instruction used as a reference for unmanned aircraft access to airspace, including operational limits, VLOS, responsibilities, and authorization requirements.
CORPAS
RPAS Operations Course adopted as the team's theoretical training reference, especially for the remote pilot and any operator who may take control of the radio during the mission.
GSD (Ground Sample Distance)
Size in meters of one pixel on the ground; smaller GSD = better resolution.
VLOS (Visual Line of Sight)
Direct visual contact between the pilot and the drone during flight; required by Brazilian law.
RTH (Return to Home)
Automatic function that returns the drone to the takeoff point when signal is lost.
Photogrammetry
3D reconstruction technique based on overlapping 2D images.
Orthomosaic
Georeferenced large-area image created by joining overlapping photographs.
DEM (Digital Elevation Model)
Digital elevation model; raster representing topography in height pixels.
Point Cloud
Set of 3D points (X, Y, Z) that represent the geometry of an object or surface.
Gimbal
Mechanical system with motors that stabilizes the camera on up to 3 axes during flight.
Compass Calibration
Procedure to reset the drone's magnetic sensor; reduces orientation errors.
IMU (Inertial Measurement Unit)
Sensor that measures acceleration and rotation; essential for drone stability.
Rocky Shore
Geological formation of consolidated rocks in a coastal marine environment; habitat of high biodiversity.
Overlap
Percentage of common area between consecutive photos; typically 80% front and 60% side in photogrammetry.
GIS (Geographic Information System)
Software for geospatial analysis; allows manipulation of shapefiles, rasters, and topological analyses.
SIPAER
Aeronautical Accident Investigation and Prevention System; the foundation of Brazilian aviation safety.
e-NotaM
DECEA electronic system for notifying air operations; mandatory for RPAS.
LiDAR
Light Detection and Ranging; sensor that measures distance using lasers; creates a highly accurate 3D point cloud.
WGS84
Global geodetic reference system; standard for GPS and geographic coordinates.
UTM (Universal Transverse Mercator)
Cartographic projection that divides the Earth into zones; Brazil uses zones 21-25.
BVLOS (Beyond Visual Line of Sight)
Operation beyond the pilot's visual line of sight; requires additional regulatory requirements and does not apply to the standard protocol in this presentation.
Safe Takeoff Point
Flat, unobstructed, marked, and isolated area used for takeoff and landing with minimal risk to the team and third parties.
Waypoint
Geographic point programmed into the automatic flight plan; defines the route, altitude, and behavior of the aircraft.
Failsafe
Set of automatic safety routines (such as RTH) triggered in critical events, for example signal loss or low battery.
Geofencing
Virtual geographic barrier that limits flight areas and prevents entry into prohibited or sensitive zones.
EXIF Metadata
Embedded image information (GPS, time, camera, exposure) essential for traceability and photogrammetric processing.
RTK (Real-Time Kinematic)
High-precision GNSS technique with centimeter-level corrections in real time, useful for improving positional accuracy of final products.
PPK (Post-Processed Kinematic)
Positional correction applied after the flight using raw GNSS data; an alternative to RTK for improving georeferencing.
GCP (Ground Control Point)
A ground control point with precise coordinates, used to improve the geometric quality of the orthomosaic and 3D model.
Check Point
Independent validation point used to measure positional error of products without influencing model adjustment.
RMS Error
Statistical indicator of the difference between observed and estimated coordinates; the smaller, the better the spatial accuracy.
DSM and DTM
DSM represents surfaces with objects (vegetation/structures). DTM seeks to represent only the terrain, removing elements above ground.
Orthorectification
Geometric correction of the image to remove distortions caused by relief and perspective, allowing reliable spatial measurements.
Front and Side Overlap
Percentages of intersection between consecutive photos in the same direction (front) and between adjacent strips (side), critical for 3D reconstruction.
Rolling Shutter
Distortion effect caused by sequential sensor reading during movement; can degrade photogrammetric products in fast flights.
AGL Height (Above Ground Level)
Altitude measured relative to the local ground, not sea level; essential parameter for maintaining consistent GSD.
Slope
Terrain inclination calculated from elevation models, important for interpreting the dynamics of rocky shores.
Environmental Baseline
Set of initial data used as a reference to compare future changes in monitoring campaigns.
QA/QC (Quality Assurance / Quality Control)
Quality assurance and control procedures that verify the consistency, completeness, and reliability of collected and processed data.
Go/No-Go Plan
Objective criteria to decide whether to execute or abort the mission based on safety, weather, documentation, and equipment condition.