The use of smartphones as low-cost forestry hypsometers
Various applications are currently available for Android that allows the estimation of tree heights by using the 3D accelerometer on smartphones. Some make the estimation using the image on the screen, while others point with the edges of the terminal.
Researchers from the Universitat de Lleida have studied the measurement errors obtained with HTC Desire and Samsung Galaxy Note compared to those from Blume Leiss and Vertex IV hypsometers. The results indicate that the errors of the uncalibrated smartphones significantly exceed those of traditional forestry apparatus.
However, calibration is a very easy procedure and enables the smartphones to achieve adequate quality levels. The relative errors when pointing with the edges of the terminal show no significant differences compared to Blume Leiss.
Click here for source (Silva Fennica)