1. A system for use in precision agriculture comprising: a. a self-contained unmanned aerial vehicle (UAV) sensor payload including: i. a plurality of sensors including gyroscopes, accelerometers, magnetometers, and a GNSS receiver, ii. an image sensor sensitive to near-infrared (NIR), iii. an image sensor sensitive to red-green-blue (RGB), iv. an integrated processor and supporting hardware, wherein all sensors are time-synchronized and co-located, and the relative orientations of the sensors are known; b. on-board or off-board hardware and software configured to: i. compute position and attitude estimates of the self-contained unmanned aerial vehicle (UAV) sensor payload at each instant images are collected by the NIR and RGB imager sensors a(ii) and a(iii) using data from the time-synchronized and co-located plurality of sensors in a(i), ii. determine a transformation between NIR and RGB imagery from the co-located and time-synchronized NIR and RGB image sensor a(ii) and a(iii) that maps a projection of each scene point in an image from one of the image sensors to a projection of the same point in an image from the other image sensor, iii. compute vegetation indices using the NIR and RGB imagery obtained by the NIR and RBG image sensor a(ii) and a(iii) using the transformation from b(ii), iv. use the computed position and attitude estimates from b(i) and the known relative orientations of the NIR and RGB image sensors a(ii) and a(iii) relative to the plurality of sensors in a(i) to geo-register and stitch the RGB and NIR imagery and the computed vegetation indices from (b)(iii).