Format of GPS File for OneButtonTM
The OneButtonTM software can take a collection of UAV or aerial images with position and orientation information, and create an accurate orthomosaic. Usually, OneButtonTM reads the position and orientation information directly from the metadata embedded in the image files. But if it cannot for any reason, then a “GPS file” with the necessary information can be imported. This GPS file should be in the format of a CSV (comma separated values) ASCII file, with columns for, at least, image name, x location of image center, and y location of image center. These columns can be in any order, but the user should review how OneButtonTM interprets each column when it opens the file. If OneButtonTM does not correctly interpret which column represents which variable, then the user can choose from a menu which type of information is contained in each column.
An example GPS file might look like this, when opened in a text editor:
IMG_0959,74.15576667,15.30296278,195.98
IMG_0960,74.15560417,15.30342167,198.13
IMG_0961,74.15543389,15.30388083,197.72
IMG_0962,74.15527167,15.30450639,199.04
IMG_0963,74.15511667,15.30504389,199.44
IMG_0964,74.15490583,15.30564889,200.69
IMG_0965,74.15472556,15.30630583,199.47
IMG_0966,74.15457278,15.30684361,198.75
IMG_0977,74.15399083,15.30684611,198.32
IMG_0978,74.15417972,15.30625806,199.39
IMG_0979,74.15439278,15.30556611,202.09
IMG_0980,74.15456250,15.30498167,201.75
In this file, the first column contains image names, the second column contains longitude, the third column contains latitude, and the last column contains elevation above mean sea level. If available, additional columns could contain information about sensor orientation in the form of omega, phi, and kappa, and/or pitch, roll, and azimuth (yaw) values.
An optional"orientation" column can also be added to identify how the sensor was placed on the flying platform. This is mainly relevant for manned airplanes where the flyer can choose how to install the sensor (in the direction of flight or against the direction of flight). There is an image of the different values for this parameter in Appendix D of the OneButtonTM User's Manual that is accessible when running the software. The values are either 1, 2, 3 or 4. If you do not know the orientation you can leave out this column, and the software will calculate the orientation on its own.
ps 11/8/2016