COVER INFORMATION Station: HOB_DBBC (Code Ho ) Experiment: RadioAstron AGN polarization imaging Exp. Code: gg081c Schedule Version: 1.00 Processed by SCHED version: 11.40 Release 11.4. March 14, 2015 PI: Jose L. Gomez Address: Instituto de Astrofisica de Andalucia-CSIC Glorieta de la Astronomia E-18008 Granada, Spain Phone: +79165452842 EMAIL: jlgomez@iaa.es, alobanov@mpifr-bonn.mpg.de Fax: Phone during observation: +79165452842 Observing mode: K-band,Q-band, dual-pol Notes: K-band, Radioastron-compatible frequency setup P-CAL is ON Tsys is ON auto-level (AGC) is ON Schedule for HOB_DBBC (Code Ho ) Page 2 RadioAstron AGN polarization imaging UP: D => Below limits; H => Below horizon mask; W => still slewing at end; blank => Up. Early: Seconds between end of slew and start. Dwell: On source seconds. Disk: GBytes recorded to this point. TPStart: Recording start time. Frequencies are LO sum (band edge). SYNC: Time correlator is expected to sync up. ---------------------------------------------------------------------------------------- Start UT Source Start / Stop Early Disk TPStart Stop UT LST EL AZ HA UP ParA Dwell GBytes SYNC ---------------------------------------------------------------------------------------- --- Tue 7 Mar 2017 Day 66 --- ---------- K-band VLBI scans. Space segment 01: 0851+202 with EVN+KVN+LBA ---------- Next scan frequencies: 22236.00 22236.00 22236.00 22236.00 Next BBC frequencies: 436.00 436.00 436.00 436.00 Next scan bandwidths: 16.00 16.00 16.00 16.00 13 00 00 0851+202 09 51 31 25.9 345.4 0.9 85.1 0 0 12 59 49 13 01 00 --- 09 52 31 25.8 345.2 0.9 85.1 60 2 12 59 50 13 01 10 0851+202 09 52 41 25.8 345.1 0.9 85.0 7 2 No stop 13 10 00 --- 10 01 33 25.4 342.9 1.1 84.2 530 20 13 01 01 13 10 30 0851+202 10 02 03 25.3 342.8 1.1 84.2 26 20 13 10 19 13 11 30 --- 10 03 03 25.3 342.5 1.1 84.1 60 22 13 10 20 13 11 40 0851+202 10 03 13 25.3 342.5 1.1 84.1 7 22 No stop 13 20 00 --- 10 11 34 24.8 340.4 1.3 83.3 500 38 13 11 31 13 20 30 0851+202 10 12 04 24.7 340.2 1.3 83.2 26 38 13 20 19 13 21 30 --- 10 13 05 24.7 340.0 1.3 83.2 60 40 13 20 20 13 21 40 0851+202 10 13 15 24.7 340.0 1.3 83.1 7 40 No stop 13 30 00 --- 10 21 36 24.1 337.9 1.4 82.3 500 57 13 21 31 13 30 30 0851+202 10 22 06 24.1 337.8 1.4 82.3 26 57 13 30 19 13 31 30 --- 10 23 06 24.0 337.5 1.5 82.2 60 59 13 30 20 13 31 40 0851+202 10 23 16 24.0 337.5 1.5 82.2 7 59 No stop 13 40 00 --- 10 31 38 23.4 335.4 1.6 81.3 500 75 13 31 31 ---------- K-band VLBI scans. Space segment 01: 0851+202 with EVN+KVN+LBA cont. ---------- 13 40 30 0851+202 10 32 08 23.4 335.3 1.6 81.3 26 75 13 40 19 13 41 30 --- 10 33 08 23.3 335.1 1.6 81.2 60 78 13 40 20 13 41 40 0851+202 10 33 18 23.3 335.0 1.6 81.2 7 78 No stop 13 50 00 --- 10 41 39 22.6 333.0 1.8 80.3 500 94 13 41 31 ---------- K-band VLBI scans. Space segment 01: 0851+202 with EVN+KVN+LBA cont. ---------- 13 50 30 0851+202 10 42 09 22.6 332.9 1.8 80.3 26 94 13 50 19 13 51 30 --- 10 43 10 22.5 332.7 1.8 80.2 60 96 13 50 20 13 51 40 0851+202 10 43 20 22.5 332.6 1.8 80.1 7 96 No stop 14 00 00 --- 10 51 41 21.7 330.7 1.9 79.3 500 113 13 51 31 Schedule for HOB_DBBC (Code Ho ) Page 3 RadioAstron AGN polarization imaging UP: D => Below limits; H => Below horizon mask; W => still slewing at end; blank => Up. Early: Seconds between end of slew and start. Dwell: On source seconds. Disk: GBytes recorded to this point. TPStart: Recording start time. Frequencies are LO sum (band edge). SYNC: Time correlator is expected to sync up. ---------------------------------------------------------------------------------------- Start UT Source Start / Stop Early Disk TPStart Stop UT LST EL AZ HA UP ParA Dwell GBytes SYNC ---------------------------------------------------------------------------------------- --- Tue 7 Mar 2017 Day 66 --- ---------- K-band VLBI scans. Ground segment 01: target source with LBA ---------- 14 00 30 0851+202 10 52 11 21.7 330.6 1.9 79.2 26 113 14 00 19 14 01 30 --- 10 53 11 21.6 330.3 2.0 79.1 60 115 14 00 20 14 01 40 0851+202 10 53 21 21.6 330.3 2.0 79.1 7 115 No stop 14 10 30 --- 11 02 13 20.7 328.2 2.1 78.1 530 132 14 01 31 ---------- K-band VLBI scans. Ground segment 01: target source with EVN+KVN+LBA ---------- 14 11 00 0851+202 11 02 43 20.7 328.1 2.1 78.0 26 132 14 10 49 14 12 00 --- 11 03 43 20.6 327.9 2.1 77.9 60 135 14 10 50 14 12 10 0851+202 11 03 53 20.6 327.9 2.1 77.9 7 135 No stop 14 20 30 --- 11 12 14 19.7 326.0 2.3 76.9 500 151 14 12 01 14 21 00 0851+202 11 12 44 19.7 325.9 2.3 76.9 27 151 14 20 49 14 22 00 --- 11 13 45 19.6 325.6 2.3 76.8 60 153 14 20 50 14 22 10 0851+202 11 13 55 19.6 325.6 2.3 76.7 7 153 No stop 14 30 30 --- 11 22 16 18.7 323.7 2.4 75.7 500 170 14 22 01 14 31 00 0851+202 11 22 46 18.6 323.6 2.4 75.7 27 170 14 30 49 14 32 00 --- 11 23 46 18.5 323.4 2.5 75.5 60 172 14 30 50 14 32 10 0851+202 11 23 56 18.5 323.4 2.5 75.5 7 172 No stop 14 40 30 --- 11 32 18 17.6 321.6 2.6 74.4 500 188 14 32 01 ---------- K-band VLBI scans. Ground segment 01: target source with EVN+KVN+LBA ---------- 14 41 00 0851+202 11 32 48 17.5 321.4 2.6 74.4 27 188 14 40 49 14 42 00 --- 11 33 48 17.4 321.2 2.6 74.2 60 190 14 40 50 14 42 10 0851+202 11 33 58 17.4 321.2 2.6 74.2 7 190 No stop 14 50 30 --- 11 42 19 16.4 319.4 2.8 73.1 500 207 14 42 01 14 51 00 0851+202 11 42 49 16.3 319.3 2.8 73.0 27 207 14 50 49 14 52 00 --- 11 43 49 16.2 319.1 2.8 72.8 60 209 14 50 50 14 52 10 0851+202 11 43 59 16.2 319.1 2.8 72.8 7 209 No stop 14 58 30 --- 11 50 21 15.4 317.7 2.9 71.9 380 222 14 52 01 Schedule for HOB_DBBC (Code Ho ) Page 4 RadioAstron AGN polarization imaging UP: D => Below limits; H => Below horizon mask; W => still slewing at end; blank => Up. Early: Seconds between end of slew and start. Dwell: On source seconds. Disk: GBytes recorded to this point. TPStart: Recording start time. Frequencies are LO sum (band edge). SYNC: Time correlator is expected to sync up. ---------------------------------------------------------------------------------------- Start UT Source Start / Stop Early Disk TPStart Stop UT LST EL AZ HA UP ParA Dwell GBytes SYNC ---------------------------------------------------------------------------------------- --- Tue 7 Mar 2017 Day 66 --- ---------- K-band VLBI scans. Ground segment 01: target source with LBA ---------- 15 00 30 0851+202 11 52 21 15.2 317.3 2.9 71.6 116 222 15 00 19 15 01 30 --- 11 53 21 15.1 317.1 3.0 71.5 60 224 15 00 20 15 01 40 0851+202 11 53 31 15.0 317.1 3.0 71.4 7 224 No stop 15 10 00 --- 12 01 52 14.0 315.4 3.1 70.1 500 240 15 01 31 ---------- K-band VLBI scans. Ground segment 01: target source with EVN+KVN+LBA ---------- 15 10 30 0851+202 12 02 23 13.9 315.3 3.1 70.1 27 240 15 10 19 15 11 30 --- 12 03 23 13.8 315.1 3.1 69.9 60 242 15 10 20 15 11 40 0851+202 12 03 33 13.8 315.0 3.1 69.9 7 242 No stop 15 20 30 --- 12 12 24 12.6 313.3 3.3 68.4 530 260 15 11 31 15 21 00 0851+202 12 12 54 12.5 313.2 3.3 68.3 27 260 15 20 49 15 22 00 --- 12 13 54 12.4 313.0 3.3 68.1 60 262 15 20 50 15 22 10 0851+202 12 14 04 12.4 312.9 3.3 68.1 7 262 No stop 15 30 30 --- 12 22 26 11.2 311.3 3.4 66.6 500 278 15 22 01 15 31 00 0851+202 12 22 56 11.2 311.2 3.5 66.5 27 278 15 30 49 15 32 00 --- 12 23 56 11.0 311.0 3.5 66.3 60 281 15 30 50 15 32 10 0851+202 12 24 06 11.0 311.0 3.5 66.3 7 281 No stop 15 40 30 --- 12 32 27 9.8 309.4 3.6 64.6 500 297 15 32 01 15 41 00 0851+202 12 32 58 9.8 309.3 3.6 64.5 27 297 15 40 49 15 42 00 --- 12 33 58 9.6 309.1 3.6 64.3 60 299 15 40 50 15 42 10 0851+202 12 34 08 9.6 309.1 3.6 64.3 7 299 No stop 15 50 30 --- 12 42 29 8.4 307.5 3.8 62.5 500 316 15 42 01 15 51 00 0851+202 12 42 59 8.3 307.4 3.8 62.4 27 316 15 50 49 15 52 00 --- 12 43 59 8.2 307.2 3.8 62.1 60 318 15 50 50 15 52 10 0851+202 12 44 09 8.1 307.2 3.8 62.1 7 318 No stop 15 59 30 --- 12 51 31 7.1 305.8 3.9 60.4 440 332 15 52 01 16 00 00 0851+202 12 52 01 7.0 305.7 3.9 60.3 27 332 15 59 49 16 01 00 --- 12 53 01 6.8 305.6 4.0 60.0 60 335 15 59 50 16 01 10 0851+202 12 53 11 6.8 305.5 4.0 60.0 7 335 No stop 16 09 00 --- 13 01 02 5.6 304.1 4.1 57.9 470 350 16 01 01 Schedule for HOB_DBBC (Code Ho ) Page 5 RadioAstron AGN polarization imaging UP: D => Below limits; H => Below horizon mask; W => still slewing at end; blank => Up. Early: Seconds between end of slew and start. Dwell: On source seconds. Disk: GBytes recorded to this point. TPStart: Recording start time. Frequencies are LO sum (band edge). SYNC: Time correlator is expected to sync up. ---------------------------------------------------------------------------------------- Start UT Source Start / Stop Early Disk TPStart Stop UT LST EL AZ HA UP ParA Dwell GBytes SYNC ---------------------------------------------------------------------------------------- --- Tue 7 Mar 2017 Day 66 --- ---------- K-band VLBI scans. Space segment 02: Target down, observing calibrator for LBA ---------- 16 15 00 1814-637 13 07 03 42.4 144.1 -5.2 12.7 151 350 16 14 49 16 16 00 --- 13 08 03 42.5 144.0 -5.2 13.0 60 352 16 14 50 16 16 10 1814-637 13 08 13 42.5 144.0 -5.2 13.1 7 352 No stop 16 25 00 --- 13 17 05 43.5 143.8 -5.1 15.5 530 370 16 16 01 16 25 30 1814-637 13 17 35 43.5 143.7 -5.1 15.6 27 370 16 25 19 16 26 30 --- 13 18 35 43.6 143.7 -5.0 15.9 60 372 16 25 20 16 26 40 1814-637 13 18 45 43.6 143.7 -5.0 16.0 7 372 No stop 16 35 00 --- 13 27 06 44.5 143.5 -4.9 18.3 500 388 16 26 31 16 35 30 1814-637 13 27 36 44.6 143.5 -4.9 18.4 27 388 16 35 19 16 36 30 --- 13 28 37 44.7 143.4 -4.9 18.7 60 390 16 35 20 16 36 40 1814-637 13 28 47 44.7 143.4 -4.9 18.7 7 390 No stop 16 45 00 --- 13 37 08 45.6 143.3 -4.7 21.0 500 407 16 36 31 16 45 30 1814-637 13 37 38 45.7 143.2 -4.7 21.1 27 407 16 45 19 16 46 30 --- 13 38 38 45.8 143.2 -4.7 21.4 60 409 16 45 20 16 46 40 1814-637 13 38 48 45.8 143.2 -4.7 21.4 7 409 No stop 16 55 00 --- 13 47 10 46.7 143.1 -4.6 23.7 500 425 16 46 31 16 55 30 1814-637 13 47 40 46.8 143.1 -4.6 23.8 27 425 16 55 19 16 56 30 --- 13 48 40 46.9 143.1 -4.5 24.1 60 428 16 55 20 16 56 40 1814-637 13 48 50 46.9 143.1 -4.5 24.2 7 428 No stop 17 05 00 --- 13 57 11 47.8 143.0 -4.4 26.4 500 444 16 56 31 17 05 30 1814-637 13 57 41 47.9 143.0 -4.4 26.5 27 444 17 05 19 17 06 30 --- 13 58 42 48.0 143.0 -4.4 26.8 60 446 17 05 20 17 06 40 1814-637 13 58 52 48.0 143.0 -4.4 26.8 7 446 No stop 17 15 00 --- 14 07 13 49.0 142.9 -4.2 29.1 500 463 17 06 31 17 15 30 1814-637 14 07 43 49.0 142.9 -4.2 29.2 27 463 17 15 19 17 16 30 --- 14 08 43 49.1 142.9 -4.2 29.5 60 465 17 15 20 17 16 40 1814-637 14 08 53 49.1 142.9 -4.2 29.5 7 465 No stop 17 25 00 --- 14 17 15 50.1 142.9 -4.1 31.7 500 481 17 16 31 Schedule for HOB_DBBC (Code Ho ) Page 6 RadioAstron AGN polarization imaging UP: D => Below limits; H => Below horizon mask; W => still slewing at end; blank => Up. Early: Seconds between end of slew and start. Dwell: On source seconds. Disk: GBytes recorded to this point. TPStart: Recording start time. Frequencies are LO sum (band edge). SYNC: Time correlator is expected to sync up. ---------------------------------------------------------------------------------------- Start UT Source Start / Stop Early Disk TPStart Stop UT LST EL AZ HA UP ParA Dwell GBytes SYNC ---------------------------------------------------------------------------------------- --- Tue 7 Mar 2017 Day 66 --- 17 25 30 1814-637 14 17 45 50.1 142.9 -4.1 31.9 27 481 17 25 19 17 26 30 --- 14 18 45 50.2 143.0 -4.0 32.1 60 484 17 25 20 17 26 40 1814-637 14 18 55 50.3 143.0 -4.0 32.2 7 484 No stop 17 35 00 --- 14 27 16 51.2 143.0 -3.9 34.4 500 500 17 26 31 ---------- K-band VLBI scans. Ground segment 02: Target down, so observing calibrator for LBA ---------- 17 35 30 1814-637 14 27 46 51.2 143.0 -3.9 34.5 27 500 17 35 19 17 36 30 --- 14 28 46 51.3 143.0 -3.9 34.8 60 502 17 35 20 17 36 40 1814-637 14 28 57 51.4 143.1 -3.9 34.8 7 502 No stop 17 45 30 --- 14 37 48 52.3 143.2 -3.7 37.1 530 519 17 36 31 ---------- K-band VLBI scans. Ground segment 02: Target down, so observing calibrator for LBA ---------- 17 45 30 1814-637 14 37 48 52.3 143.2 -3.7 37.1 -2 519 No stop 17 46 30 --- 14 38 48 52.4 143.2 -3.7 37.4 58 521 17 45 31 17 46 40 1814-637 14 38 58 52.5 143.2 -3.7 37.4 7 521 No stop 17 55 30 --- 14 47 50 53.4 143.4 -3.6 39.7 530 539 17 46 31 ---------- K-band VLBI scans. Ground segment 02: Target down, so observing calibrator for LBA ---------- 17 55 30 1814-637 14 47 50 53.4 143.4 -3.6 39.7 -2 539 No stop 17 56 30 --- 14 48 50 53.5 143.5 -3.5 39.9 58 541 17 55 31 17 56 40 1814-637 14 49 00 53.6 143.5 -3.5 40.0 7 541 No stop 18 05 30 --- 14 57 51 54.5 143.8 -3.4 42.2 530 558 17 56 31 ---------- K-band VLBI scans. Ground segment 02: Target down, so observing calibrator for LBA ---------- 18 05 30 1814-637 14 57 51 54.5 143.8 -3.4 42.2 -2 558 No stop 18 06 30 --- 14 58 51 54.6 143.8 -3.4 42.5 58 560 18 05 31 18 06 40 1814-637 14 59 01 54.6 143.8 -3.4 42.5 7 560 No stop 18 15 30 --- 15 07 53 55.6 144.2 -3.2 44.8 530 577 18 06 31 ---------- K-band VLBI scans. Ground segment 02: Target down, so observing calibrator for LBA ---------- 18 15 30 1814-637 15 07 53 55.6 144.2 -3.2 44.8 -2 577 No stop 18 16 30 --- 15 08 53 55.7 144.3 -3.2 45.0 58 579 18 15 31 18 16 40 1814-637 15 09 03 55.7 144.3 -3.2 45.1 7 579 No stop 18 25 30 --- 15 17 55 56.7 144.7 -3.1 47.3 530 596 18 16 31 Schedule for HOB_DBBC (Code Ho ) Page 7 RadioAstron AGN polarization imaging UP: D => Below limits; H => Below horizon mask; W => still slewing at end; blank => Up. Early: Seconds between end of slew and start. Dwell: On source seconds. Disk: GBytes recorded to this point. TPStart: Recording start time. Frequencies are LO sum (band edge). SYNC: Time correlator is expected to sync up. ---------------------------------------------------------------------------------------- Start UT Source Start / Stop Early Disk TPStart Stop UT LST EL AZ HA UP ParA Dwell GBytes SYNC ---------------------------------------------------------------------------------------- --- Tue 7 Mar 2017 Day 66 --- ---------- K-band VLBI scans. Ground segment 02: Target down, so observing calibrator for LBA ---------- 18 25 30 1814-637 15 17 55 56.7 144.7 -3.1 47.3 -2 596 No stop 18 26 30 --- 15 18 55 56.8 144.8 -3.0 47.5 58 598 18 25 31 18 26 40 1814-637 15 19 05 56.8 144.8 -3.0 47.6 7 598 No stop 18 35 30 --- 15 27 56 57.7 145.4 -2.9 49.8 530 616 18 26 31 ---------- K-band VLBI scans. Ground segment 02: Target down, so observing calibrator for LBA ---------- 18 35 30 1814-637 15 27 56 57.7 145.4 -2.9 49.8 -2 616 No stop 18 36 30 --- 15 28 56 57.8 145.4 -2.9 50.0 58 618 18 35 31 18 36 40 1814-637 15 29 06 57.8 145.5 -2.9 50.1 7 618 No stop 18 45 30 --- 15 37 58 58.8 146.1 -2.7 52.2 530 635 18 36 31 18 45 30 1814-637 15 37 58 58.8 146.1 -2.7 52.2 -2 635 No stop 18 46 30 --- 15 38 58 58.9 146.2 -2.7 52.5 58 637 18 45 31 18 46 40 1814-637 15 39 08 58.9 146.2 -2.7 52.5 7 637 No stop 19 00 00 --- 15 52 30 60.2 147.4 -2.5 55.8 800 663 18 46 31 SETUP FILE INFORMATION: NOTE: If DOPPLER, FREQ, or BW were used, see the individual scans for the final BBC settings. ======== Setup file: ra1cm2.set Matching groups in ./gg081c_freq.dat: ho1cm_low Setup group: 18 Station: HOB_DBBC Total bit rate: 256 Format: MARK5B Bits per sample: 2 Sample rate: 32.000 Number of channels: 4 DBE type: DBBC_DDC Speedup factor: 1.00 Disk used to record data. 1st LO= 21800.00 21800.00 21800.00 21800.00 Net SB= U U L L IF SB = U U U U Pol. = RCP LCP RCP LCP BBC = 1 9 1 9 BBC SB= U U L L IF = A1 B1 A1 B1 The following frequency sets based on these setups were used. Frequency Set: 12 Setup file default. Used with PCAL = 1MHz LO sum= 22236.00 22236.00 22236.00 22236.00 BBC fr= 436.00 436.00 436.00 436.00 Bandwd= 16.00 16.00 16.00 16.00 Matching frequency sets: 12 Track assignments are: track1= 2, 4, 6, 8 barrel=roll_off POSITIONS OF SOURCES USED IN RECORDING SCANS Source Source position (RA/Dec) Error (B1950) (J2000) (Date) (mas) * FAKERA 11 57 21.769299 * 12 00 00.000000 12 00 59.861040 0.00 85 16 41.77889 * 85 00 00.00000 84 54 12.96182 0.00 From catalog imbedded in main SCHED input file. fake circumpolar target for a TS to look at * 1814-637 18 14 45.949299 * 18 19 35.002600 18 21 12.288328 0.00 -63 47 03.20742 *-63 45 48.20500 -63 44 57.59250 0.00 From catalog imbedded in main SCHED input file. possble calibrator source for LBA?? 1328+307 13 28 49.657778 * 13 31 08.288070 13 31 56.345486 0.00 J1331+3030 30 45 58.64060 * 30 30 32.95924 30 25 08.66218 0.00 * 3C286 ./gg081c_sources.radioastron WSRT calibrator, not for 92cm, rfc_2013d Petrov, 2013, unpublished 542 observati * 0716+714 07 16 13.029739 * 07 21 53.448474 07 23 50.595719 0.00 J0721+7120 71 26 15.17406 * 71 20 36.36340 71 18 40.38874 0.00 ./gg081c_sources.radioastron AGN, rfc_2013d Petrov, 2013, unpublished 42370 observations, RA-AO3-04, RA-AO2-1 * 0851+202 08 51 57.250618 * 08 54 48.874930 08 55 48.283390 0.00 J0854+2006 20 17 58.41733 * 20 06 30.64078 20 02 24.49441 0.00 OJ287 ./gg081c_sources.radioastron AGN, rfc_2013d Petrov, 2013, unpublished 213710 observations, RA-AO3-04, RA-AO3- SOURCE SCAN SUMMARY FOR SOURCES LISTED ABOVE Scan hours are for recording scans only. Baseline hours are only counted for scans above horizon at both ends. Source Setup file Frequency sets Observing hours (duplicates not shown) Scan Baseline FAKERA ra1cm2.set 21 5.750 0.000 1814-637 ra1cm2.set 9 10 11 12 13 2.639 20.990 3C286 ra1cm2.set 51 0.267 0.000 ra7mm2.set 52 0.367 0.000 0716+714 ra1cm2.set 1 2 5 6 14 15 16 17 18 19 2 + 12.436 152.486 ra2cm2.set 43 55 0.450 14.171 ra7mm2.set 23 36 59 60 4.575 33.390 0851+202 ra1cm2.set 1 2 5 6 9 10 11 12 13 14 15 + 17.411 1982.713 ra2cm2.set 43 55 0.864 39.108 ra7mm2.set 36 52 59 60 0.911 54.094 EFFECT OF SOLAR CORONA The solar corona can cause unstable phases for sources too close to the Sun. SCHED provides warnings at individual scans for distances less than 10 degrees. The distance from the Sun to each source in this schedule is: Source Sun distance (deg) FAKERA 99.9 1814-637 78.3 3C286 138.8 0716+714 104.6 0851+202 143.1 Barry Clark estimates from predictions by Ketan Desai of IPM scattering sizes that the Sun will cause amplitude reductions on the longest VLBA baselines at a solar distance of 60deg F^(-0.6) where F is in GHz. For common VLBI bands, this is: 327 MHz 117. deg 610 MHz 81. deg 1.6 GHz 45. deg 2.3 GHz 36. deg 5.0 GHz 23. deg 8.4 GHz 17. deg 15.0 GHz 12. deg 22.0 GHz 9. deg 43.0 GHz 6. deg