2017 Aug. 21st, Solar Eclipse Observations by Hinode/XRT

25-Jul-2017 prepared by Aki Takeda
2-Aug-2017 update Hinode eclipse timings with the latest prediction data.
3-Aug-2017 modify observation times taking orbit events into account.
8-Aug-2017 update XOB description and data volume estimate.
9-Aug-2017 update description based on the agreement at XRT weekly mtg.
14-Aug-2017 added the result of the test run on 8/10.
17-Aug-2017 describe modified XOBs.
28-Aug-2017 added observation results.

Hinode Eclipses & HOP requests

Hinode Eclipses (click image to enlarge)

Episode 1
16:50:19 -- 17:05:38 UT Episode 2
no disk occultation (~18:21) Episode 3
19:35:41 -- 19:50:35 UT Episode 4
no disk occultation (~21:15)
HOP 339 : "Polar Plume Observations During the 2017 Aug 21 Total Solar Eclipse"
- - Full-disk component: Two sets of full-Sun images within three hours on either side of totality. Images to compare with the totally-eclipsed corona, before and after the times of ground-based totality. (The time of maximum total eclipse at their ground locations is about 17:18 and 17:34 UT on 21 Aug 2017.)
- - Polar-limb component: TARGET: First choice is a PCH. TIMING: Total observation should run for >~ 1 hour on polar coronal hole (or polar quiet Sun) region. FIELD OF VIEW: 512x512 desired (384x384 acceptable). EXPOSURE TIME: Long exposure time (AEC setting = 2). FILTERS: Al/poly, Al/mesh. CADENCE: About 30 seconds between images would be acceptable.
HOP 340 : "XRT MegaMovie (XRT-MM) During the 2017 Aug 21 Total Solar Eclipse"
- Approximately continuous full-disk coronal images for a 95-minute period coinciding with the ground-based totality over the US: 17:15 - 18:50 UT. FIELD OF VIEW:1024x1024, with 2x2 binning. FILTERS: Hi- and low-cadence pairs, with Al/poly for high cadence and Al/mesh for low cadence. EXPOSURE TIME: Fixed-exposure image pairs, to form short-longexposure image composites. Suggestions are: for Al/poly, 4-5 sec + 0.5-1 sec; for Al/mesh, 2 sec + 0.25 sec. CADENCE: About 60 seconds between image pairs. Al/poly would run for nine image pairs.

XRT observation timeline

Orbit events for 21-Aug-2017, 15-20UT (data provided on 2017/08/03).

15:00 UT (Poining to North-limb)
15:03 -- 16:40 UT (North-limb component of HOP 339, confirmed by A. Sterling).
(BadPhoto: 15:47:00 -- 16:25:30)
16:40 UT (Poining to DC)
16:43 -- 16:47 UT (XRT regular synoptics).
16:47 -- 17:10 UT (Hinode eclipse Ep.1).
17:10 -- 18:53 UT (HOP 340 & Full-disk component of HOP 339).
(BadPhoto: 17:25:00 -- 18:02:00) --- We will keep taking images.
18:53 -- 19:03 UT (XRT 7-filter synoptics).
(BadPhoto: 19:03:30 -- 19:38:30)
19:30 UT (Poining to S-limb to support EIS cal.)
19:33 -- 20:05 UT (Hinode eclipse Ep.3, Start obs while in SAA).
20:05 UT (Poining to North-limb)
20:08 -- 20:42 UT (Polar-limb component of HOP 339). (BadPhoto: 20:42:00 -- 21:16:00)
20:43 UT (Poining to Contact Point [-876,339]) [Optional]
21:10 -- 21:20 UT (Hinode eclipse Ep.4, at limb pnt. Starts in SAA). [Optional]

XOBs

Hinode eclipses Ep. 1:

XOB#1BBC was modified (it was not uploaded yet, so simply overwitten).
[for Movie] Al-poly 4x4 short(88ms)/long(723ms) pair, 30 sec cad. 22-min duration.
[high-res for EPO] Al-poly 1x1 8sec/8sec doublet, every 7 min. (to be taken at 16:54 & 17:01).
data volume estimation by COT : 242Mbits/22min.

XOB#1BBC was created.
[for Movie] Al-poly 4x4 long(1024ms)/short(256ms) pair, 30 sec cad. 22-min duration.
[high-res for EPO] Al-poly 1x1 8sec/8sec doublet, every 7 min. (to be taken at 16:54 & 17:01).
data volume estimation by COT : 242Mbits/22min.

XOB#1BB3 was created.
[for Movie] Al-poly 4x4 long(500ms)/short(128ms) pair, 30 sec cad. 22-min duration.
[high-res for EPO] Al-poly 1x1 8sec/8sec doublet, every 7 min. (to be taken at 16:54 & 17:01).
data volume estimation by COT : 242Mbits/22min.

Hinode eclipses Ep. 3 and 4:

XOB#1BBB was modified (it was not uploaded yet, so simply overwitten).
Al-poly 4x4 short(88ms)/long(723ms) pair, 30 sec cad. 25-min duration.
data volume estimation by COT : 167Mbits/25min.
duration(25min) is suitable for Ep. 3, but too long for ep.4.

XOB#1BBB was created (for Movie).
Al-poly 4x4 long(1024ms)/short(256ms) pair, 30 sec cad. 25-min duration.
data volume estimation by COT : 167Mbits/25min.
duration(25min) is suitable for Ep. 3, but too long for ep.4.

XOB#1BB0 was created (for Movie).
a modified version of XOB#1B4C (used for 2016/09/01 eclipse obs.).
Al-poly 4x4 long(500ms)/short(128ms) pair, 30 sec cad. 25-min duration.
data volume estimation by COT : 167Mbits/25min.
duration(25min) is suitable for Ep. 3, but too long for ep.4.

HOP 339 (full-Sun): Regular synoptics and HOP 340 images will serve for this purpose.

HOP 339 (polar-limb):

XOB#1BB1 was created.
Al-poly 1x1 8s and Al-mesh 1x1 4s, AEC=2, 512x512 pair, 30 sec cad.
data volume estimation by COT : 334Mbits/60min, 189Mbits/34min.

HOP 340:

XOB#1BBD was created.
Al-poly 2x2 (short/long=177/4096ms) pair with occasional Al-mesh 2x2 (short/long=128/2897ms) pair (take one Al-mesh after 9 Al-poly).
1024x1024, cadence 60 sec, Fixed exposure.
data volume estimation by COT : 1182Mbits/90min.

XOB#1BB2 was created.
Al-poly 2x2 (short/long=500/4096ms) pair with occasional Al-mesh 2x2 (short/long=128/2048ms) pair (take one Al-mesh after 9 Al-poly).
1024x1024, cadence 60 sec, Fixed exposure.
data volume estimation by COT : 1182Mbits/90min.

Data volume estimation

Estimation by COT simulator

HOP339 PCH : 334 Mbits
XRT regular synoptics : 109 Mbits
Hinode eclipse ep.1 : 242 Mbits
HOP340 full-sun : 1182 Mbits
XRT 7-filter synoptics : 175 Mbits
Hinode eclipse ep.3 : 167 Mbits
HOP339 PCH : 189 Mbits
Hinode eclipse ep.4 : 84 Mbits

Total data volume (15:00 -- 21:20 UT): 2482 Mbits
Rough estimate of total vol. for entire 3 days timeline : 5000 to 5600 Mbits.

Test runs on 8/10

Test run was performed on 10-Aug., 15 to 20 UT (no test for the part after 20UT). Prepared XOBs were run at the same timing, same order. Note that we don't observe flares during the eclipse observations (XRT_FLD_DIS, XRT_FLD_CTL_DIS were set in each sequence).

Brief summary

Data flow was OK. All sequences ran without a problem (like MDP stuck).
HOP 339 (XOB#1BB1): observed with AEC=2. Exposures went to 16sec for both Al-mesh and Al-poly. Images look OK.
Hinode eclipses (XOB#1BB3, #1BB0): 512x512 images with 512ms exposure are a little under, while 2048x2018 8sec images look OK. Modified XOBs to double the exposure time of 512x512 images were created.
HOP 340 (XOB#1BB2): Images during twilight become fairly faint, but the quality should be slightly better next week, since the twilight is shallower than on 8/10. The following images during SAA can serve the purpose of HOP 340.

The following items are still source of uncertainty ...

DR not emptied for the test run.
EIS is planning observation (HOP339) and alibration(stray light) during Hinode eclipse(s).
SOT does not have obs plan for the eclipse (for now).

Real Observations on 21-Aug.

Hinode eclipse episode 1

Mp4 movie (orange) (from JAXA/ISAS press release)
Mp4 movie (black/white) (from JAXA/ISAS press release)

Hinode eclipse 2048x2048 special 5-image composite

           0 21-AUG-2017 16:43:46   Apol/Open   0.0164 1024x1024
           1 21-AUG-2017 16:43:52   Apol/Open   0.1819 1024x1024
           2 21-AUG-2017 17:01:02   Apol/Open   0.7254 512x512
           3 21-AUG-2017 17:01:29   Apol/Open   8.1928 2048x2048
           4 21-AUG-2017 17:01:47   Apol/Open   8.1933 2048x2048

For comparison:
Before eclipse 1024x1024 9-image composite.
Eclipse Red color version by M. Weber and T. Jibben.
Corrected Eclipse movie by M. Weber, T. Jibben and J. Prchlik.

Hinode eclipse episode 3
Javascript movie (reversed orange color table)

Hinode eclipse episode 4
Javascript movie (reversed orange color table)

HOP 339
- Al_poly movie (Javascript)
- Al_mesh movie (Javascript)

HOP 340
- Al_poly movie (reduced size, Javascript)
- Al_mesh movie (reduced size, Javascript)

Episode 1 16:50:19 -- 17:05:38 UT	Episode 2 no disk occultation (~18:21)	Episode 3 19:35:41 -- 19:50:35 UT	Episode 4 no disk occultation (~21:15)