Photogrammetry & Remote Sensing
Aerial Imagery Acquisition & 3D Mapping
Flight planning aims to design an aerial survey coverage that meets the requirements for interim and final project deliverables. Most importantly, the flight altitude for aerial photography must take into account the diversity of terrain in a project area.
The orthoimages are geometrically corrected so that the resulting image has the geometric integrity of a map, and the mosaics are orthoimages tessellated into a single image.
Other products can be produced, such as vector GIS layers with features such as roads, buildings, hydrology, and other ground features.
Flight planning at MipMap is carried out by experienced photogrammetric and aerial survey personnel according to Company Flight Operations procedures.
Flight planning at MipMap is carried out by experienced photogrammetric and aerial survey personnel according to Company Flight Operations procedures.
Aerial Drone Image Acquisition Workflow Sample
Aerial triangulation is the process of continuous densification and extension of ground control by computational means.
This process includes the establishment of GCPs, internal orientation, measurement and transfer of all tie, check, and control points that appear on all photographs, and least squares block adjustment.
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MipMap technologies utilise large format digital aerial imagery in photogrammetry processes. A particular advantage of the new large-format digital photogrammetric imagery is the high-quality multispectral radiometry.
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2D/3D Satellite Mapping
Multiple overlapping images, called stereo images, are collected as the sensor flies along a flight path. We use these images to produce digital elevation data, mosaics and orthophoto images.
For good accuracy, we use VHR satellite imagery such as 0.31m resolution WorldView3 stereo satellite imagery to produce DEM and orthophoto data.
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To produce accurate orthophotos from satellite imagery, the images must undergo orthorectification and geometric correction according to a map projection. This process also requires the use of a rigorous geometric model, GCPs and a high accuracy DEM.
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As MipMap Technologies, we manage this process in the most accurate way with our technical team specialised in this field.
DSM/DTM/DEM Generation
A Digital Elevation Model (DEM) is a 3D representation of the surface of a terrain. By filtering out non-ground points such as bridges and roads, a smooth digital elevation model is obtained.
Digital Surface Modelling (DSM) is the creation of a digital representation of a visible surface.
Digital Terrain Model (DTM), also known as Digital Elevation Modelling, is the creation of a digital representation of ground topography and terrain.
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We carry out all the necessary processing steps to produce a highly fidelity DTM:
- Creating a point cloud combining terrain data with positioning information,
- Provision of all raw and processed data,
- Classification of terrain data in .las format,
- Classified point cloud provided in grid tiles,
- Processing of DTM to ensure no gaps/holes,
- Defining areas obscured by features with a polygon
- Interpolation of points
- Separate classification of interpolated points.
- Removal of watershed obstructions (bridges, culverts, etc.)
- Determination of DTM density.
Orthophoto/True Orthophoto Production
An orthophoto is an aerial photograph or image that has been geometrically corrected so that the scale is uniform. The conversion of aerial photographs to "maps" involves resampling the images while systematically removing the distortions to produce a flat surface or map.
True Ortho imagery is created from surface data in a fully automated process. The advantage is that prominent objects, such as buildings, are not skewed.
The basis for true ortho imagery is an aerial photo flight with a high degree of overlap.
We generally use an overlap of 80% in the direction of flight and 60% across the flight direction to obtain a true orthophoto.
Thanks to their geometric accuracy, the True Ortho images we provide are much more suitable for use in engineering surveying than normal orthophotos.
Lidar Acquisition, Processing
& Point Cloud Classification
Due to the rapid development of technology, the increased accuracy of GNSS, and the increasing demand for even more accurate digital surface models, airborne laser scanning has undergone significant development.
Airborne laser scanning is an active remote sensing technology that can rapidly collect data from large areas.
Airborne laser scanning is often coupled with airborne imagery, allowing the point clouds and imagery to be fused, resulting in a higher-quality 3D product.
The LIDAR acquisiton and processing includes:
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- Planning (coverage, point density, flight parameters),
- Deployment of GNSS base stations (if required),
- Calibration of equipment,
- LiDAR surveying.
Many of these data processing steps can be automated. There are procedures built into the processing software developed by MipMap Technologies that can classify features and detect building roofs, trees...
Many of these data processing steps can be automated. There are procedures built into the processing software developed by MipMap Technologies that can classify features and detect building roofs, trees...
Mobile Mapping System (MMS) Measurements & Feature Extraction
Mobile mapping techniques are used for 3D modeling and mapping along roads and streets.
We carry out 3D panoramic surveys (imagery and cloud data) along the project routes to produce point cloud data and imagery with an accuracy of 10cm on the ground.
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The survey captures landmarks and elements such as buildings, parks, gardens, bridges, tunnels, and all available elements along the road such as road signs, signals, footpaths, trees, and others.
