Radiometric fidelity of calibrated airborne video imagery is important if the imagery is to be used for quantitative analysis of target surfaces. A four-channel Multispectral Airborne Video System (MAvS) is used at Charles Sturt University (CSU) for a range of environmenfal and agricultural monitoring applications. The radiometric distortions in the MAVSim agery could occur because of lens characteristics in the form of vignetting effects and optical aberrations. This paper details the control experiments conducted to detect and quantify such distortions. The vignetting in particular is shown to be creating a nonuniform brightness level across the MAVS imagery. The paper then develops efficient procedures to correct the vignetting in the MAVS imagery by producing relevant correction coefticients, templates, and equations. The accumcy of these de-vignetting (correction) procedures is shown to be comparable to the accumcy of similar corrections reported elsewhere. An investigation into the effect of spectrum related vignetting on the MAVS imagery due to spectral filter characteristics found negligible distortions that did not warrant corrections. This particular type of vignetting is usually caused by the wavelength ships in the band-pass window of a filter at large incident angles.
|Number of pages||8|
|Journal||Photogrammetric Engineering and Remote Sensing|
|Publication status||Published - 2001|