MAPIR offers our durable Diffuse Reflectance Standard Calibration Target Package (T3-R125), which contains 4 reference standard targets of known reflectance. Diffuse and total reflectance percent measurements from 250-2500nm were made using multiple Shimadzu spectrophotometers incorporating an integrating sphere. The lambertian reflectance panels can be captured from any angle thanks to similar diffuse and total reflection properties, though capturing straight-on is recommended. Our computer vision software automatically finds the QR symbol in the target images and calculates the pixel to reflectance relationship using the known target material reflectance (data download here).
The reflectance targets are composed of a felt-like sheet material adhered to a plastic substrate. Care should be taken to ensure the targets are debris-free to produce the best calibration results, often a puff of air is all that is needed to clean them. The target's housing is made of durable polypropylene plastic and the QR fiducial pattern material is a UV durable, laminated label.
|Package Model||Reference Target Dimensions||
Recommended Capture Distance (Survey3W)
||Recommended Capture Distance (Survey3N)|
|T3-R50||2.0" x 2.0" (50 x 50 mm)||8 in - 13 ft (0.2 - 4.0 m)||20 in - 33 ft (0.5 - 10.0 m)|
|T3-R125||5.0" x 5.0" (125 x 125 mm)||20 in - 33 ft (0.5 - 10.0 m)||40 in - 105 ft (1.0 - 32.0 m)|
The outer case of the T3-R125 is impact resistant, crushproof, dustproof and IP67 waterproof (IP67 rating = waterproof to a depth of 1 meter for 30 minutes when closed). The built-in handle is easy to grip, rotates and is flexible. Both of the large hinged clasps close the case securely with a twist, and there are 2 additional keys included to lock it. A large center hole between the handle also allows an additional padlock to be used (not included).
To use the target, simply capture a photo of the entire open package, making sure the QR side and the 4 target side are visible. Try to make sure no harsh/dark shadows intrude on the white outer perimeter of the QR label, rotating the target as needed. Full capturing tutorial here.
Using our MAPIR Camera Control (MCC) or MAPIR Cloud software you can provide photos of this target package and the QR fiducial pattern should be automatically detected, regardless of 3D pose. The pixel values from the targets will be measured and calibration formulas will be calculated. The reflectance calibration will then be applied to the remainder of your images until a new target image is found (depends on MCC recalibration setting value). An unlimited number of target images can be used to correct your images for reflectance over time and across various lighting environments (i.e. cloudy days). Using the Analyze tab in MCC you can calculate the raster/index images (for example NDVI) and then apply a color map (LUT).
Total Closed Dimensions: 12.2" x 15.1" x 2.8" (30.99 x 38.35 x 7.11 cm)
Total Open Dimensions: 23.75" x 15.1" x 1.8" (60.33 x 38.35 x 4.60 cm)
Each Target: 5.0" x 5.0" (125 x 125 mm)
Weight: 4.0 lbs (1.80 kg)
Buoyancy: 9 lbs
Weight Capacity: 15 lbs
100% MADE IN THE USA
Compliant with airline ATA-300 specifications
Automatic pressure equalization system
(1) Diffuse Reflectance Standard Calibration Target Package (T3-R125), containing 4 measured reflectance standard targets and an identification QR label
(2) Plastic locking keys