Location/Site
Indian Head Canyon Open Space
(33°01’53.25″N 117°16’47.57″W)
Date
July 3rd, 2026
Time
07:34 AM
Executive Summary
Mission Objective
Develop a baseline spatial dataset of a natural, undeveloped open space area using a lawnmower pattern with longitudinal passes along a SW-NE axis, captured with nadir imagery. This flight will serve as a base model for future techniques and amendments.
The purpose of this mission is to examine the capture of natural vegetation on a hilly site using a fixed AGL. The elements of focus are:
- Coverage of different elevations on the site using a fixed AGL and determining whether there is sufficient overlap.
- Vegetation detail in the orthomosaic
- Topography detail in the point cloud and textured mesh
Mission success will be defined as the creation of a complete orthomosaic, point cloud, and DSM with minimal visible distortion and occlusions.
Intended Applications
- Site documentation
- Vegetation inventory
- Drainage assessment
- Existing conditions documentation
- Baseline comparison for future site monitoring
- Capture strategy evaluation
Mission Planning
Airspace
- Class G, Uncontrolled
- No TFRs
Weather Conditions
- Temperature: 66.2º F
- Wind: 4.3 mph, 297° NW
- Cloud Cover: OVC, 1000’ AGL
- Lighting Conditions: Broken, Overcast
Mission Success Criteria
- Complete image alignment
- Continuous orthomosaic coverage
- Minimal visible block deformation
- Relative measurements within ±5% of field measurements
- Clearly documented dataset limitations
- Safe and complete mission without any deviations or conflicts
Data Capture Strategy
Flight Parameters
| Parameter | Value |
|---|---|
| Flight Pattern | Automated Lawnmower Grid (manually created) |
| Altitude | 150 ft AGL from launch elevation |
| Flight Duration | 21 minutes |
| Camera Angle | Nadir (-90°) |
| Front Overlap | 80% |
| Side Overlap | 65% |
| Speed | 3.13 mph |
| Photo Interval | 5 sec |
| ISO | 100 |
| Shutter | 1/640 sec |
| Aspect Ratio | 4:3 |
| Image Capture Count | 228 JPEG (8064 x 6048) |
| Lighting | Broken clouds |
Processing Summary
| Metric | Result |
|---|---|
| Images Reconstructed | 227/227 shots (100.0%) |
| Average Reprojection Error | 1.52 px |
| Average GSD | 1.0 cm/pixel |
| Sparse Points | 249439 over 250393 points (99.6%) |
| Dense Points | 18.34 million |
| GPS Source/ CRS | Consumer GPS/WGS84 (No RTK/PPK) |
| GPS Error RMS | .88m |
| Outputs | Orthomosaic, DSM, DTM, Point Cloud, Mesh |
Interpretation
Orthomosaic
Produced complete visual coverage of the project area with no significant stitching failures. The orthomosaic would be suitable for documentation and visual inspection.
Point Cloud
Successfully reconstructed terrain and vegetation. Areas beneath tall vegetation were occluded due to the nadir acquisition strategy. Thin branches did get reconstructed.
Textured Mesh
Produced a coherent three-dimensional representation of the site. Quality decreased beneath mature trees and along vertical surfaces where image geometry was insufficient.
DSM
Successfully represented overall site topography, including the gradual elevation increase across the parking lot. Vegetation was roughly preserved, as expected, in the Digital Surface Model. The DSM provided a relative elevation scale for the site.
Quality Assessment
Strengths
- Complete image reconstruction
- Uniform lighting provided strong detail and color
- Minimal large-scale block deformation
- Repeatable acquisition workflow
Limitations
- Absolute positional accuracy limited by consumer GNSS
- Dataset unsuitable for engineering-grade positioning
Quality Validation
Relative Measurement Validation
Since the purpose of this mission is to examine the capture of natural vegetation on a hilly site using a fixed AGL, the emphasis was not on comparing measurement accuracy but rather on comparing coverage across different elevations on the site.
Although GNSS corrections were not used, the model was evaluated against local coordinates, datum, and elevations to assess absolute accuracy.
Interpretation
No measurements were taken for verification
This dataset is suitable for educational use and approximate measurements but lacks the positional accuracy required for engineering, surveying, or legal-grade geospatial analysis.
This dataset is suitable for educational use and approximate measurements but lacks the positional accuracy required for engineering, surveying, or legal-grade geospatial analysis.
Conclusion
Mission 2B turned out to be a lower-quality reproduction than Mission 2A.
This dataset was acquired using nadir imagery only in a single-axis lawnmower pattern at a constant altitude of 150’ AGL from the launch site. Admittedly, I neglected to calculate the highest point on the site before flying, so the flight elevation was low (99′ AGL) at the highest point of the mapping area. This resulted in a weak side overlap of 51% and a theoretically weak reconstruction of the western edge (Saxony Rd.) of the model.
Again, no GNSS corrections, surveyed control points, or checkpoints were used on this model. Compared to a Google Earth basemap, the model is significantly skewed on the Z-axis with elevations approx
The purpose of this mission was to test the Mini 4 Pro’s ability to capture a larger area with varied terrain while preserving detail in natural vegetation. Since this was a natural open space, I did not focus on the relative accuracy of the validation measurements.
The resulting orthomosaic provides good visual coverage of the site. There is some occlusion under the larger trees and shrubs. There is good visual detail of the vegetation, terrain, and bordering roads.
However, a comparison with the noted point elevations provided by the City of Encinitas indicates a significant shift of approximately. 60’ in vertical positioning. Again, a lack of absolute accuracy is expected with consumer GPS without GNSS corrections, but the degree of inaccuracy is greater than expected.
This dataset is suitable for progress status, inventory assessment, horizontal surface inspection, and approximate measurements, but would not be adequate for engineering, surveying, or construction-grade decision-making.
Mission 3B Hypothesis
Mission 3B will include additional nadir capture with a 90º crosshatch pattern, which should improve the relative accuracy and positioning. In missions 1 & 2, the crosshatch pattern introduced additional warping and stitching errors, so this is a possible concern. Because the site has a lot of natural vegetation and is quite irregular, it will be more difficult to determine whether there are warping or stitching errors.
The vertical shift will be measured to see if there is improvement, but an improvement in accuracy is not expected.
Again, the point cloud did not reconstruct well. Most of the vertical surfaces were occluded, some more so than Mission 2A. Many of the 90º corners, like curbs, stair steps, and the bases of walls, were very rounded. The building’s corrugated metal roof was occluded, likely due to poor image stitching. There was more noise throughout the model.
Overall, this mission, using a crosshatch pattern with nadir imagery, did not reconstruct well. This dataset in orthomosaic output would be adequate only for a rough asset inventory and progress status. The 3D model is inadequate, with omissions, noise, and warping. The Mission 2A point cloud is of better quality.