Unsatisfactory results? The factors below can contribute to a failed map or one that only covers a portion of the intended area. Scroll through the camera roll and compare the projections to your intended map area.
In order to capture the data needed to stitch a map, input imagery should face the ground.
Don't include images:
- taken from ground level with a hand-held camera rather than drone. Test images from your drone should be OK.
- that capture the sky/horizon.
Though beautiful, the images below would decrease the chances of a good map.
Flying higher is the single best way to improve the chance of stitching a successful map.
The default altitude in the DroneDeploy app is 250 feet (or about 75 meters). This works well for a variety of settings.
For tall objects, such as tall buildings, the flight should be planned so that the highest point of your map is high relative to the object of interest rather than to the ground.
In order to use Map Engine, be sure that your data includes GPS info (with latitude, longitude, and altitude) in the EXIF data.
Geo-tagging with Mission Planner
See here for instructions to manually geo-tag your images using Mission Planner.
Example geotag detection:
To see where the images on the map were, click on the Projections button outlined in red below.
When the map consists of one line of imagery, it is hard for the software to distinguish patterns and create a map.
Capturing imagery with sufficient overlap (60% or higher) is essential to creating a good map.
Flying higher is key to achieving high overlap. We recommend testing flights at different altitudes to get the right combination of resolution and overlap.
Fields and Forests
Forests or highly homogenous fields are particularly difficult to stitch. We recommend increasing altitude as well as setting frontlap and sidelap to 70 or 80% when mapping these areas.
Flying at night or on a cloudy day means the images are captured with less light. Darker images contain less info and are harder to stitch. We recommend flying in clear, bright conditions to the extent possible.
While low-light images can reduce mapping quality, if you are flying on a very clear and bright day and taking images of bright structures or topography, make sure your camera does not take overexposed pictures.
Water is notoriously difficult to map by drone photogrammetry due to its constantly changing surface, refraction/reflection of light, and tendency to have hard-to-determine patterns. The anomaly of homogeneous imagery affects all image processing software. It’s just that difficult for computers to process.
When flying over areas with water, limit the amount of images that you take and upload into DroneDeploy that are exclusively of water.
Fisheye lenses will produce a panoramic image, which is useful for viewing wide areas in one picture but not for stitching quality maps. As a result of the non-uniform resolution around the edges, fisheye imagery does not work well with mapping applications like DroneDeploy and should be avoided.
Updated 5 months ago