Fig. 3. An example of each of the fit parameters (intensity, shift and width) using the spectral profiles of N IV at 765.15 Å, obtained from the first set of observations (JOP055) as a function of distance from the limb. The coronal hole boundary is located approximatively from the limb. It is marked by the vertical line near the center of the frame. The vertical solid line on the left, representing the position of the limb, is located just outside the limits of the image on the detector (dashed vertical lines) in this dataset. The scale at the top of each frame indicates , where is the heliocentric angle. Negative shifts signify blue shifts.