Multi-Needle Langmuir probe (mNLP) data on the Investigation of Cusp Irregularities (ICI) 4 sounding rocket

<p>Documentation for file: ICI4_mNLP_01112021.mat</p> <p>&nbsp;</p> <ol> <li> <p><strong>The mNLP system on ICI-4</strong></p> </li> </ol> <p>The mNLP system on ICI-4 consisted of four cylindrical Langmuir probes with a diameter of 0.51 mm and a length of 25 mm [1,2]. The instruments allowed for current measurements at a sampling rate of 8680.5 Hz. The mNLP data included in the file are 1) the raw currents (&lsquo;I_mnlp&rsquo;) in which spikes have been removed using a median filter over ten data points, and 2) the &ldquo;filtered currents&rdquo; (&lsquo;I_mnlp_filt&rsquo;). For the latter, the spin of the payload and the three first harmonics were removed using a band-pass filter [1,2]. Additionally, components with frequencies larger than 1kHz were also removed.</p> <p>&nbsp;</p> <p>&nbsp;</p> <ol> <li> <p><strong>Variables:</strong></p> </li> </ol> <table> <tbody> <tr> <td> <p>Variable name</p> </td> <td> <p>Units</p> </td> <td> <p>Description/Comment</p> </td> </tr> <tr> <td> <p>time_noNans</p> </td> <td> <p>seconds</p> </td> <td> <p>Time of flight since launch.</p> </td> </tr> <tr> <td> <p>Alt</p> </td> <td> <p>Km</p> </td> <td> <p>Altitude of the payload.</p> </td> </tr> <tr> <td> <p>I_mnlp</p> </td> <td> <p>Ampere</p> </td> <td> <p>Currents obtained by the four cylindrical Langmuir probes. The 1^st-4^th columns contain the currents obtained by the probes with bias voltages of 3V, 4.5V, 6V, and 7.5 V, respectively. The data was filtered using a median filter over ten data points.</p> </td> </tr> <tr> <td> <p>I_mnlp_filt</p> </td> <td> <p>Ampere</p> </td> <td> <p>Same as&nbsp;I_mnlp with additional filtering of currents&nbsp;using band-pass filters [1,2].</p> </td> </tr> </tbody> </table> <p>&nbsp;</p> <p><strong>Acknowledgement</strong></p> <p>The mNLP experiment and the ICI-4 campaign were funded through the Research Council of Norway. Thanks to Lasse Clausen, Espen Trondsen,&nbsp;J&oslash;ran I. Moen, David Michael Bang-Hauge, Bj&oslash;rn Lybekk, and the Mechanical Workshop at the University of Oslo, Norway.&nbsp;</p> <p><br> &nbsp;</p> <p>1. Bekkeng, T.&thinsp;A., K.&thinsp;S. Jacobsen, J.&thinsp;K. Bekkeng, A. Pedersen, T. Lindem, J.‐P. Lebreton, and J.&thinsp;I. Moen (2010), Design of a multi‐needle Langmuir probe system, Meas. Sci. Technol., 21, 085,903, doi:10.1088/0957‐0233/21/8/085903</p> <p>2. Jacobsen, K. S., Pedersen, A., Moen, J. I., &amp; Bekkeng, T. A. (2010), A new Langmuir probe concept for rapid sampling of space plasma electron density. Measurement Science and Technology, 21(8), <a href="https://doi.org/10.1088/0957%E2%80%900233/21/8/085902">https://doi.org/10.1088/0957‐0233/21/8/085902</a></p>