SOTSP: HOP475 / AR13614
2024-03-20T00:59:00 to 2024-03-20T01:19:35
Science Goal: [SOOP: COORD_CALIBRATION (CC1_111) and (CC1_115)] Cross-calibration of the Solar Orbiter Polarimetric and Helioseismic Imager (SO/PHI)
Program: Deep Normal Map, 20"x164", 1-side, Q75
Target: Active Region
xcen=-656 ycen=320
Instrument: SOTSP
HOP/JOP: 475
Description:
Scientific Justification: Perform coordinated observations with the Polarimetric and Helioseismic Imager (PHI) instrument on board the Solar Orbiter (SO) spacecraft and the Hinode spectropolarimeter (Hinode/SP) during the 13th Remote Sensing Window (RSW) of the SO science mission phase that will take place between March 13 and March 24, 2024. The main goal of this HOP is to acquire co-spatial and co-temporal SO/PHI and Hinode/SP data to perform a detailed inter-calibration with the SO/PHI instrument, including both telescopes, the Full Disk Telescope (FDT) and the High Resolution Telescope (HRT). These observations will help us bring the full capabilities of the SO/PHI instrument for science, as well as to acquire additional calibration data. In the nominal mode SO/PHI provides maps of the vector magnetic field and line-of-sight velocities with both telescopes by observing the Fe 617 nm line at 5 points inside the line plus another point in the nearby continuum. In addition, an alternative mode, where 11 points are acquired inside the line, resulting in a twice as high spectral sampling, is available. This mode is used for better cross calibration for parts of this proposal. In order to fully test the capabilities of SO/PHI and monitor any possible degradation of the instruments, it is important to complement these observations with the Hinode/SP, as long as such co-observations are possible. These observations need to be taken while SO is crossing the Sun-Earth line, while SO sees the Sun from the same point of view as Hinode. In this way, a full characterization of the imaging and polarimetric properties of the SO/PHI instrument with respect to Hinode/SP is possible. As SO will leave the ecliptic at the beginning of 2025, this is the last chance to get real co-aligned observations from a vantage point on or close to Earth. The SO/PHI observations that will be used for cross-calibration will be taken on March 19 and 20, 2024, when SO is at a distance of about 0.45 au from the Sun, and at less than 2 degrees separation with Earth. At those times, the pixel scale is about 157 km for HRT and 1400 km for FDT. The SO/PHI-FDT observations will take place during the Solar Orbiter Observation Plan (SOOP) called COORD_CALIBRATION (CC1_111) led by M. Romoli. The SO pointing at this time will be the disk center. The SO/PHI-HRT observations will take place during the Solar Orbiter Observation Plan (SOOP) called COORD_CALIBRATION (CC1_115) led by J. Hirzberger. These SO/PHI-HRT observations will be taken at locations decided about three days in advance. The pointing for Hinode should be adapted to that decision.
