What is Modulation Transfer Function Compensation (MTFC) resampling?
The Modulation Transfer Function Compensation (MTFC) parameters for the Landsat 7 (L7) Calibration Parameter File (CPF) were submitted for inclusion in the 4Q2001 CPF release. These coefficients used in the CPF are derived from on-orbit estimates of the Enhanced Thematic Mapper Plus (ETM+) along- and across-scan MTF and replace the previous coefficients, which were based on prelaunch MTF measurements in the along-scan direction only. The MTF describes how the sensor optics and electronics modulate the original signal (image), as a function of spatial frequency, in the conversion of input radiance at the ETM+ aperture to an output digital image. The goal in MTFC resampling is to partially compensate for the system response by boosting the higher spatial frequencies attenuated by the MTF. This enhances fine spatial detail (e.g., edges), but has the side effect of also increasing the image noise somewhat. This is apparent in the sample images below, where the MTFC image exhibits sharper e
