2019-09-20T20:33:14.000Z http://sot.lmsal.com Ted Tarbell LMSAL http://lmsal.com 3251 Hanover Rd, O/ADBS, B/252, Palo Alto, CA, 94304 +1-650-424-2400 tarbell@lmsal.com Hinode SOTSP Yoshitake Yasuda Tiwari and DeRosa (RCO) 379 379 null HOP379 Low-Latitude CH CH CH Coronal Hole 6 108 -20 0 0 2019-09-21T17:13:00.000Z 2019-09-21T20:29:35.000Z 108 -20 Assessing the Solar Open Magnetic Flux from the Surface Up Deep Normal Map, 90"x164", 1-side, Q75 Main Objective: To characterize the coronal hole (polar or on-disk) photospheric magnetic field properties with the aim to improve the heliospheric open magnetic flux estimate. Scientific Justification: The heliospheric open magnetic flux (OMF) based on moderate-resolution magnetograms was found to be grossly underestimated compared to in situ observation. Possible explanations include systematics in the spectropolarimetry inference. We propose to observe the coronal hole (CH) photospheric field using Hinode/SP (Fe I 630 nm) in coordination with BBSO/GST (Fe 1.56 ?m). The high spatial/spectral resolution data probing two different heights will allow for a systematic investigation of various systematics (e.g., radial field assumption, stray light, noise), and are expected to improve the OMF estimate. This work is an integral component of a recent NSF grant, in which Hinode and NST data are used to train a PhD student in preparation for the imminent DKIST operation.