COVER INFORMATION Station: WSTRBORK (Code Wb ) Experiment: Snapshot Ionospheric Testing Observations Exp. Code: N05L3 Schedule Version: 1.02 Processed by SCHED version: 6.01 Release: Late March 2005 PI: James M Anderson Address: Joint Institute for VLBI in Europe Oude Hoogeveensedijk 4 7991 PD Dwingeloo The Netherlands Phone: +31 (0)521 596 542 EMAIL: anderson@jive.nl Fax: +31 (0)521 596 539 Phone during observation: +31 (0)521 596 500 Observing mode: Snapshot observations of sources at 18cm (256 Mb/s) Notes: ALBUS Ionospheric modeling test observations Phase referencing is too fast for JODRELL1 All targets are strong Schedule for WSTRBORK (Code Wb ) Page 2 Snapshot Ionospheric Testing Observations UP: D => Below limits; H => Below horizon mask. blank => Up. Early: Seconds between end of slew and start. Dwell: On source seconds. Tapes: Drive, Index, Start footage / Direction, Head Group, End footage. TPStart: Tape motion start time. Frequencies are LO sum (band edge). ---------------------------------------------------------------------------------------- Start UT Source Start / Stop Early Tapes TPStart Stop UT LST EL AZ HA UP ParA Dwell (see above) ---------------------------------------------------------------------------------------- --- Mon 6 Jun 2005 Day 157 --- Next scan frequencies: 1637.99 1637.99 1645.99 1645.99 1653.99 1653.99 1661.99 1661.99 Next BBC frequencies: 127.99 127.99 135.99 135.99 143.99 143.99 151.99 151.99 Next scan bandwidths: 8.00 8.00 8.00 8.00 8.00 8.00 8.00 8.00 23 00 00 J1323+7942 16 28 20 59.3 345.4 3.1 0.0 0 1 1 0 23 00 00 23 02 00 =1323+799 16 30 21 59.2 345.3 3.1 0.0 120 F 1 0 23 02 00 J1139+7654 16 30 21 54.9 337.9 4.8 0.0 -99 1 1 0 23 02 00 23 04 00 =1136+771 16 32 21 54.8 337.9 4.9 0.0 21 F 1 0 23 04 00 J1323+7942 16 32 21 59.1 345.2 3.1 0.0 -99 1 1 0 23 04 00 23 06 00 =1323+799 16 34 21 59.1 345.1 3.2 0.0 21 F 1 0 23 06 00 J1139+7654 16 34 21 54.7 337.9 4.9 0.0 -99 1 1 0 23 06 00 23 08 00 =1136+771 16 36 22 54.5 337.9 4.9 0.0 21 F 1 0 23 08 00 J1323+7942 16 36 22 59.0 345.0 3.2 0.0 -99 1 1 0 23 08 00 23 10 00 =1323+799 16 38 22 58.9 344.9 3.2 0.0 21 F 1 0 23 10 00 J1139+7654 16 38 22 54.4 337.9 5.0 0.0 -99 1 1 0 23 10 00 23 12 00 =1136+771 16 40 22 54.3 337.9 5.0 0.0 21 F 1 0 23 13 00 J1323+7942 16 41 22 58.8 344.8 3.3 0.0 -39 1 1 0 23 13 00 23 14 00 =1323+799 16 42 23 58.7 344.8 3.3 0.0 21 F 1 0 23 14 00 J1406+7828 16 42 23 61.1 344.9 2.6 0.0 -49 1 1 0 23 14 00 23 15 40 =1406+787 16 44 03 61.0 344.8 2.6 0.0 51 F 1 0 23 15 40 J1323+7942 16 44 03 58.7 344.7 3.3 0.0 -49 1 1 0 23 15 40 23 17 20 =1323+799 16 45 43 58.6 344.6 3.4 0.0 51 F 1 0 23 17 20 J1406+7828 16 45 43 61.0 344.7 2.7 0.0 -49 1 1 0 23 17 20 23 19 00 =1406+787 16 47 23 60.9 344.6 2.7 0.0 51 F 1 0 23 19 00 J1323+7942 16 47 23 58.5 344.6 3.4 0.0 -49 1 1 0 23 19 00 23 20 40 =1323+799 16 49 04 58.5 344.5 3.4 0.0 51 F 1 0 23 20 40 J1406+7828 16 49 04 60.8 344.5 2.7 0.0 -49 1 1 0 23 20 40 23 22 20 =1406+787 16 50 44 60.8 344.4 2.7 0.0 51 F 1 0 Schedule for WSTRBORK (Code Wb ) Page 3 Snapshot Ionospheric Testing Observations UP: D => Below limits; H => Below horizon mask. blank => Up. Early: Seconds between end of slew and start. Dwell: On source seconds. Tapes: Drive, Index, Start footage / Direction, Head Group, End footage. TPStart: Tape motion start time. Frequencies are LO sum (band edge). ---------------------------------------------------------------------------------------- Start UT Source Start / Stop Early Tapes TPStart Stop UT LST EL AZ HA UP ParA Dwell (see above) ---------------------------------------------------------------------------------------- --- Mon 6 Jun 2005 Day 157 --- 23 22 20 J1323+7942 16 50 44 58.4 344.5 3.4 0.0 -49 1 1 0 23 22 20 23 24 00 =1323+799 16 52 24 58.3 344.4 3.5 0.0 51 F 1 0 23 24 00 J1357+7643 16 52 24 61.3 340.7 2.9 0.0 -41 1 1 0 23 24 00 23 25 40 =1357+769 16 54 04 61.2 340.6 2.9 0.0 59 F 1 0 23 25 40 J1323+7942 16 54 04 58.3 344.3 3.5 0.0 -41 1 1 0 23 25 40 23 27 20 =1323+799 16 55 45 58.2 344.3 3.5 0.0 59 F 1 0 23 27 20 J1357+7643 16 55 45 61.1 340.5 3.0 0.0 -41 1 1 0 23 27 20 23 29 00 =1357+769 16 57 25 61.0 340.4 3.0 0.0 59 F 1 0 23 29 00 J1323+7942 16 57 25 58.1 344.2 3.6 0.0 -41 1 1 0 23 29 00 23 30 40 =1323+799 16 59 05 58.1 344.2 3.6 0.0 59 F 1 0 23 30 40 J1357+7643 16 59 05 60.9 340.3 3.0 0.0 -41 1 1 0 23 30 40 23 32 20 =1357+769 17 00 46 60.8 340.3 3.0 0.0 59 F 1 0 23 32 20 J1323+7942 17 00 46 58.0 344.1 3.6 0.0 -41 1 1 0 23 32 20 23 34 00 =1323+799 17 02 26 57.9 344.1 3.6 0.0 59 F 1 0 23 40 00 J1745+1720 17 08 27 53.7 164.8 -0.6 0.0 134 1 1 0 23 40 00 23 44 00 =1743+173 17 12 27 53.8 166.4 -0.6 0.0 240 F 1 0 23 44 00 J1752+1734 17 12 27 53.8 163.5 -0.7 0.0 -19 1 1 0 23 44 00 23 45 40 =1750+175 17 14 08 53.8 164.2 -0.6 0.0 81 F 1 0 23 45 40 J1745+1720 17 14 08 53.9 167.1 -0.5 0.0 -19 1 1 0 23 45 40 23 47 20 =1743+173 17 15 48 53.9 167.8 -0.5 0.0 81 F 1 0 23 47 20 J1752+1734 17 15 48 53.9 164.8 -0.6 0.0 -19 1 1 0 23 47 20 23 49 00 =1750+175 17 17 28 54.0 165.5 -0.6 0.0 81 F 1 0 23 49 00 J1745+1720 17 17 28 54.0 168.4 -0.5 0.0 -19 1 1 0 23 49 00 23 50 40 =1743+173 17 19 09 54.0 169.1 -0.4 0.0 81 F 1 0 23 50 40 J1752+1734 17 19 09 54.0 166.2 -0.6 0.0 -19 1 1 0 23 50 40 23 52 20 =1750+175 17 20 49 54.1 166.8 -0.5 0.0 81 F 1 0 23 53 20 J1745+1720 17 21 49 54.1 170.2 -0.4 0.0 40 1 1 0 23 53 20 23 54 00 =1743+173 17 22 29 54.1 170.5 -0.4 0.0 40 F 1 0 23 54 00 J1756+1535 17 22 29 52.0 166.4 -0.6 0.0 -22 1 1 0 23 54 00 23 55 40 --- 17 24 09 52.1 167.0 -0.5 0.0 78 F 1 0 Schedule for WSTRBORK (Code Wb ) Page 4 Snapshot Ionospheric Testing Observations UP: D => Below limits; H => Below horizon mask. blank => Up. Early: Seconds between end of slew and start. Dwell: On source seconds. Tapes: Drive, Index, Start footage / Direction, Head Group, End footage. TPStart: Tape motion start time. Frequencies are LO sum (band edge). ---------------------------------------------------------------------------------------- Start UT Source Start / Stop Early Tapes TPStart Stop UT LST EL AZ HA UP ParA Dwell (see above) ---------------------------------------------------------------------------------------- --- Mon 6 Jun 2005 Day 157 --- 23 55 40 J1745+1720 17 24 09 54.2 171.1 -0.4 0.0 -22 1 1 0 23 55 40 23 57 20 =1743+173 17 25 50 54.2 171.8 -0.3 0.0 78 F 1 0 23 57 20 J1756+1535 17 25 50 52.2 167.6 -0.5 0.0 -22 1 1 0 23 57 20 23 59 00 --- 17 27 30 52.2 168.3 -0.5 0.0 78 F 1 0 --- Start: Mon 6 Jun 2005 Day 157 -- Stop: Tue 7 Jun 2005 Day 158 --- 23 59 00 J1745+1720 17 27 30 54.2 172.5 -0.3 0.0 -22 1 1 0 23 59 00 00 00 40 =1743+173 17 29 10 54.3 173.2 -0.3 0.0 78 F 1 0 00 00 40 J1756+1535 17 29 10 52.3 169.0 -0.5 0.0 -22 1 1 0 00 00 40 00 02 20 --- 17 30 51 52.3 169.6 -0.4 0.0 78 F 1 0 00 02 20 J1745+1720 17 30 51 54.3 173.9 -0.3 0.0 -22 1 1 0 00 02 20 00 04 00 =1743+173 17 32 31 54.3 174.5 -0.2 0.0 78 F 1 0 00 04 00 J1719+1745 17 32 31 54.7 185.4 0.2 0.0 -35 1 1 0 00 04 00 00 05 40 =1717+178 17 34 11 54.7 186.1 0.2 0.0 65 F 1 0 00 05 40 J1745+1720 17 34 11 54.3 175.2 -0.2 0.0 -35 1 1 0 00 05 40 00 07 20 =1743+173 17 35 51 54.4 175.9 -0.2 0.0 65 F 1 0 00 07 20 J1719+1745 17 35 51 54.7 186.8 0.3 0.0 -35 1 1 0 00 07 20 00 09 00 =1717+178 17 37 32 54.7 187.4 0.3 0.0 65 F 1 0 00 09 00 J1745+1720 17 37 32 54.4 176.6 -0.1 0.0 -35 1 1 0 00 09 00 00 10 40 =1743+173 17 39 12 54.4 177.3 -0.1 0.0 65 F 1 0 00 10 40 J1719+1745 17 39 12 54.6 188.1 0.3 0.0 -35 1 1 0 00 10 40 00 12 20 =1717+178 17 40 52 54.6 188.8 0.4 0.0 65 F 1 0 00 12 20 J1745+1720 17 40 52 54.4 178.0 -0.1 0.0 -35 1 1 0 00 12 20 00 14 00 =1743+173 17 42 32 54.4 178.6 -0.1 0.0 65 F 1 0 00 17 00 J2148+0657 17 45 33 22.9 109.9 -4.0 0.0 -33 1 1 0 00 17 00 00 26 00 =2145+067 17 54 34 24.2 112.0 -3.9 0.0 507 F 1 0 00 29 00 J2129-1538 17 57 35 7.7 129.1 -3.5 0.0 92 1 1 0 00 29 00 00 30 00 =2126-158 17 58 35 7.9 129.3 -3.5 0.0 60 F 1 0 00 30 00 J2129-1821 17 58 35 5.5 130.6 -3.5 0.0 -22 1 1 0 00 30 00 00 31 40 =2126-185 18 00 15 5.7 131.0 -3.5 0.0 78 F 1 0 Schedule for WSTRBORK (Code Wb ) Page 5 Snapshot Ionospheric Testing Observations UP: D => Below limits; H => Below horizon mask. blank => Up. Early: Seconds between end of slew and start. Dwell: On source seconds. Tapes: Drive, Index, Start footage / Direction, Head Group, End footage. TPStart: Tape motion start time. Frequencies are LO sum (band edge). ---------------------------------------------------------------------------------------- Start UT Source Start / Stop Early Tapes TPStart Stop UT LST EL AZ HA UP ParA Dwell (see above) ---------------------------------------------------------------------------------------- --- Tue 7 Jun 2005 Day 158 --- 00 31 40 J2129-1538 18 00 15 8.1 129.7 -3.5 0.0 -22 1 1 0 00 31 40 00 33 20 =2126-158 18 01 56 8.3 130.0 -3.5 0.0 78 F 1 0 00 33 20 J2129-1821 18 01 56 5.9 131.3 -3.5 0.0 -22 1 1 0 00 33 20 00 35 00 =2126-185 18 03 36 6.0 131.7 -3.4 0.0 78 F 1 0 00 35 00 J2129-1538 18 03 36 8.4 130.4 -3.4 0.0 -22 1 1 0 00 35 00 00 36 40 =2126-158 18 05 16 8.6 130.7 -3.4 0.0 78 F 1 0 00 36 40 J2129-1821 18 05 16 6.2 132.0 -3.4 0.0 -22 1 1 0 00 36 40 00 38 20 =2126-185 18 06 56 6.4 132.4 -3.4 0.0 78 F 1 0 00 38 20 J2129-1538 18 06 56 8.8 131.1 -3.4 0.0 -22 1 1 0 00 38 20 00 40 00 =2126-158 18 08 37 9.0 131.5 -3.3 0.0 78 F 1 0 00 40 00 J2130-0927 18 08 37 14.3 128.2 -3.4 0.0 -34 1 1 0 00 40 00 00 41 40 =2127-096 18 10 17 14.5 128.6 -3.3 0.0 66 F 1 0 00 41 40 J2129-1538 18 10 17 9.2 131.8 -3.3 0.0 -34 1 1 0 00 41 40 00 43 20 =2126-158 18 11 57 9.4 132.2 -3.3 0.0 66 F 1 0 00 43 20 J2130-0927 18 11 57 14.7 129.0 -3.3 0.0 -34 1 1 0 00 43 20 00 45 00 =2127-096 18 13 38 14.9 129.3 -3.3 0.0 66 F 1 0 00 45 00 J2129-1538 18 13 38 9.6 132.5 -3.3 0.0 -34 1 1 0 00 45 00 00 46 40 =2126-158 18 15 18 9.8 132.9 -3.2 0.0 66 F 1 0 00 46 40 J2130-0927 18 15 18 15.1 129.7 -3.3 0.0 -34 1 1 0 00 46 40 00 48 20 =2127-096 18 16 58 15.3 130.1 -3.2 0.0 66 F 1 0 00 49 20 J2129-1538 18 17 58 10.1 133.5 -3.2 0.0 26 1 1 0 00 49 20 00 50 00 =2126-158 18 18 38 10.1 133.6 -3.2 0.0 40 F 1 0 00 50 00 J2131-1207 18 18 38 13.0 131.5 -3.2 0.0 -25 1 1 0 00 50 00 00 51 40 =2128-123 18 20 19 13.2 131.8 -3.2 0.0 75 F 1 0 00 51 40 J2129-1538 18 20 19 10.3 134.0 -3.2 0.0 -25 1 1 0 00 51 40 00 53 20 =2126-158 18 21 59 10.5 134.4 -3.1 0.0 75 F 1 0 00 53 20 J2131-1207 18 21 59 13.4 132.2 -3.2 0.0 -25 1 1 0 00 53 20 00 55 00 =2128-123 18 23 39 13.6 132.6 -3.1 0.0 75 F 1 0 00 55 00 J2129-1538 18 23 39 10.7 134.7 -3.1 0.0 -25 1 1 0 00 55 00 00 56 40 =2126-158 18 25 19 10.9 135.1 -3.1 0.0 75 F 1 0 Schedule for WSTRBORK (Code Wb ) Page 6 Snapshot Ionospheric Testing Observations UP: D => Below limits; H => Below horizon mask. blank => Up. Early: Seconds between end of slew and start. Dwell: On source seconds. Tapes: Drive, Index, Start footage / Direction, Head Group, End footage. TPStart: Tape motion start time. Frequencies are LO sum (band edge). ---------------------------------------------------------------------------------------- Start UT Source Start / Stop Early Tapes TPStart Stop UT LST EL AZ HA UP ParA Dwell (see above) ---------------------------------------------------------------------------------------- --- Tue 7 Jun 2005 Day 158 --- 00 56 40 J2131-1207 18 25 19 13.7 133.0 -3.1 0.0 -25 1 1 0 00 56 40 00 58 20 =2128-123 18 27 00 13.9 133.3 -3.1 0.0 75 F 1 0 00 58 20 J2129-1538 18 27 00 11.0 135.5 -3.0 0.0 -25 1 1 0 00 58 20 01 00 00 =2126-158 18 28 40 11.2 135.8 -3.0 0.0 75 F 1 0 SETUP FILE INFORMATION: NOTE: If DOPPLER, FREQ, or BW were used, see the individual scans for the final BBC settings. Setup file: eo999.18cm Matches group wb18cm in /aps3/sched/catalogs/freq.dat E-mail Foley 22Jan97 MFFE, must be using Low patch Setup group: 2 Station: WSTRBORK Total bit rate: 256 Format: MKIV1:2 Bits per sample: 2 Sample rate: 16.000 Number of channels: 8 Passes/head pos: 1 Speedup factor: 1.00 1st LO= 1510.00 1510.00 1510.00 1510.00 1510.00 1510.00 1510.00 1510.00 Net SB= U U U U U U U U Pol. = RCP LCP RCP LCP RCP LCP RCP LCP BBC = 2 1 4 3 6 5 8 7 BBC SB= U U U U U U U U IF = 2N 1N 2N 1N 2N 1N 2N 1N The following frequency sets based on this setup were used. Frequency Set: 2 Setup file default. No pcal detection. LO sum= 1637.99 1637.99 1645.99 1645.99 1653.99 1653.99 1661.99 1661.99 BBC fr= 127.99 127.99 135.99 135.99 143.99 143.99 151.99 151.99 Bandwd= 8.000 8.000 8.000 8.000 8.000 8.000 8.000 8.000 Track assignments are: track1= 2, 10, 18, 26, 3, 11, 19, 27 barrel=roll_off SOURCE LIST -- Snapshot Ionospheric Testing Observations Catalog positions marked with *. Precession of date coordinates is based on stop time of first scan. Names used in schedule marked with *. Short names used in VLA and SNAP files marked with +. Observation date used in B1950/J2000 coordinate conversion (PRECDATE): 1979.900 No adjustments are made for rates (DRA, DDEC). Scan hours are for recording scans only. Baseline hours are only counted for scans above horizon at both ends. Source Source position (RA/Dec) Error (B1950) (J2000) (Date) (mas) * J1139+7654 11 36 50.402483 * 11 39 51.538717 11 40 13.600280 1.47 1136+771 77 11 09.68453 * 76 54 32.34642 76 53 06.06924 0.65 /aps3/sched/catalogs/sources.vlba VLBA Calib Srcs - GSFC sols. - catalog 2004f_astro 0.100 scan hours, 1.894 baseline hours above horizon. * J1323+7942 13 23 30.967861 * 13 23 51.569831 13 24 00.836917 2.82 1323+799 79 58 27.57995 * 79 42 51.84705 79 41 25.76771 0.44 J1323+79 /aps3/sched/catalogs/sources.vlba VLBA Calib Srcs - GSFC sols. - catalog 2004f_astro 0.283 scan hours, 8.751 baseline hours above horizon. * J1357+7643 13 57 42.117003 * 13 57 55.371534 13 58 02.806741 0.87 1357+769 76 57 53.35424 * 76 43 21.05104 76 41 58.55255 0.40 J1357+76 /aps3/sched/catalogs/sources.vlba VLBA Calib Srcs - GSFC sols. - catalog 2004f_astro 0.083 scan hours, 2.185 baseline hours above horizon. * J1406+7828 14 06 56.652670 * 14 06 36.566944 14 06 41.585608 3.71 1406+787 78 42 22.78156 * 78 28 10.40623 78 26 49.33489 0.63 /aps3/sched/catalogs/sources.vlba VLBA Calib Srcs - GSFC sols. - catalog 2004f_astro 0.083 scan hours, 2.161 baseline hours above horizon. * J1719+1745 17 17 00.324732 * 17 19 13.048481 17 19 28.559864 0.32 1717+178 17 48 08.51599 * 17 45 06.43721 17 44 37.64380 0.22 J1719+17 /aps3/sched/catalogs/sources.vlba VLBA Calib Srcs - GSFC sols. - catalog 2004f_astro 0.083 scan hours, 1.739 baseline hours above horizon. * J1745+1720 17 43 22.235899 * 17 45 35.208167 17 45 50.704699 0.32 1743+173 17 21 09.18647 * 17 20 01.42378 17 19 43.97628 0.22 J1745+17 /aps3/sched/catalogs/sources.vlba VLBA Calib Srcs - GSFC sols. - catalog 2004f_astro 0.300 scan hours, 8.450 baseline hours above horizon. * J1752+1734 17 50 33.364387 * 17 52 46.002901 17 53 01.452521 0.39 1750+175 17 34 56.75224 * 17 34 20.35018 17 34 06.02002 0.56 /aps3/sched/catalogs/sources.vlba VLBA Calib Srcs - GSFC sols. - catalog 2004f_astro 0.083 scan hours, 2.350 baseline hours above horizon. * J1756+1535 17 54 37.953509 * 17 56 53.102132 17 57 08.795390 0.32 15 35 39.32316 * 15 35 20.82657 15 35 08.41956 0.24 /aps3/sched/catalogs/sources.vlba VLBA Calib Srcs - GSFC sols. - catalog 2004f_astro 0.083 scan hours, 2.232 baseline hours above horizon. * J2129-1538 21 26 26.777538 * 21 29 12.175905 21 29 30.394943 0.21 2126-158 -15 51 50.34727 *-15 38 41.04110 -15 37 18.72623 0.30 J2129-15 /aps3/sched/catalogs/sources.vlba VLBA Calib Srcs - GSFC sols. - catalog 2004f_astro 0.250 scan hours, 9.451 baseline hours above horizon. * J2129-1821 21 26 33.897232 * 21 29 21.419113 21 29 39.890466 0.27 2126-185 -18 34 32.47350 *-18 21 22.79035 -18 19 59.57129 0.49 J2129-18 /aps3/sched/catalogs/sources.vlba VLBA Calib Srcs - GSFC sols. - catalog 2004f_astro 0.083 scan hours, 2.231 baseline hours above horizon. * J2130-0927 21 27 38.408364 * 21 30 19.088248 21 30 36.744372 0.23 2127-096 -09 40 49.81991 *-09 27 37.43511 -09 26 16.73888 0.37 /aps3/sched/catalogs/sources.vlba VLBA Calib Srcs - GSFC sols. - catalog 2004f_astro 0.083 scan hours, 2.505 baseline hours above horizon. * J2131-1207 21 28 52.676063 * 21 31 35.261755 21 31 53.136782 0.21 2128-123 -12 20 20.53564 *-12 07 04.79603 -12 05 42.84703 0.30 J2131-12 /aps3/sched/catalogs/sources.vlba VLBA Calib Srcs - GSFC sols. - catalog 2004f_astro 0.083 scan hours, 2.844 baseline hours above horizon. * J2148+0657 21 45 36.078475 * 21 48 05.458673 21 48 21.701858 0.30 2145+067 06 43 40.90460 * 06 57 38.60420 06 58 59.23842 0.20 J2148+06 /aps3/sched/catalogs/sources.vlba VLBA Calib Srcs - GSFC sols. - catalog 2004f_astro 0.150 scan hours, 7.749 baseline hours above horizon. 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) J1139+7654 70.1 J1323+7942 73.5 J1357+7643 76.8 J1406+7828 75.8 J1719+1745 139.3 J1745+1720 138.4 J1752+1734 137.7 J1756+1535 139.3 J2129-1538 116.6 J2129-1821 117.4 J2130-0927 114.3 J2131-1207 115.0 J2148+0657 103.7 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