LiF data pack supporting "Observation of diffraction contrast in scanning helium microscopy"
<p>All the experimental data from the paper is included in this data pack including both the images and the z scans. </p>
<p>Images from the paper are presented in three different formats with filenames scan00*****:</p>
<p>1) .png file which is an unprocessed image of the raw data. <br>
2) .gwy file which is an unprocessed version of the data that can be opened in Gwyddion<br>
3) .mat file which contains all the measured data that can be opened in MATLAB</p>
<p>The .mat file contains the most information and requires some explanation to easily understand.<br>
The data is saved in a structure named meas, the key fields are as follows:</p>
<p>meas.target - A matrix of the target position for each pixel, with a column for each of the x,y coordinates<br>
meas.inputs - Input parameters used in the scanning program to collect the data<br>
meas.initial_pos - Position of each the three stages at the start of the scan. The 3rd coordinate is the z scan and does not change throughout the scan<br>
meas.data - A vector of the measured current at each pixel in Amps<br>
meas.image - A matrix that represents the acquired image</p>
<p>The remaining fields are explained at the bottom of the readme.</p>
<p>The z scans are saved Z*****.mat and can be opened in MATALB.<br>
The key variables in the data files are:</p>
<p>z_position - Raw z coordinate of the positioner in nm<br>
current_z - Measured current at each point in Amps<br>
m - Horizontal scan gradient (approximately 1)<br>
m2 - Vertical scan gradient (approximately 0)<br>
step_pos - x coordiate at z_position=0<br>
step_pos_v - y coordinate at z_position=0</p>
<p>The x,y position at each point in the scan can then be obtained from<br>
x=step_pos + m*(z_position)<br>
y=step_pos_v + m2*(z_position)</p>
<p><br>
The true z distance between the pinhole and the sample in nm can be calculated from z=z_position-4295000</p>
<p>The included data in the pack contains:</p>
<p>Images presented in the paper:<br>
scan001357<br>
scan001361<br>
scan001398<br>
scan001415</p>
<p>Z000006.mat - z scan of flat region<br>
Z000008.mat - z scan of heavily distorted region<br>
Z0000012.mat - z scan of lightly distorted region<br>
Z000013.mat - z scan of HOPG</p>
<p>z_scan_movie.avi - Video illustrating how the images vary with z<br>
scan001401-scan001413 - Data to produce the video</p>
<p>In addition, the analysis scripts have been included for reference. <br>
The scripts can be used to regnerate the figures in the paper.</p>
<p><br>
The remaining fields in the meas structure are:<br>
meas.date_time - Start date and time of the scan<br>
meas.type - Scan pattern of the image. Always raster_jump<br>
meas.p1 - Unused pressure<br>
meas.p2 - Unused pressure<br>
meas.p3 - Unused pressure<br>
meas.p_srce - Source pressure at the start of the scan<br>
meas.p_diff - Differential stage pressure at the start of the scan<br>
meas.p_smpl - Sample pressure at the start of the scan<br>
meas.p_det - Detector pressure at the start of the scan<br>
meas.N_dwell - Number of current measurements taken at each pixel<br>
meas.comments - comments (unused)<br>
meas.det_params - Detector parameters used in the scan<br>
meas.labtemp - A vector of the labtemp at each pixel (unused)<br>
meas.return_state - Error status <br>
</p>
opencc-by-4.0Dec 2019View details →