Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.atnf.csiro.au/people/Tasso.Tzioumis/sched/VLA_Standard_Bands.html
Дата изменения: Unknown
Дата индексирования: Sun Apr 10 11:04:26 2016
Кодировка:
Поисковые слова: п п п п п п п п п п п п п р п р п р п р п р п р п

VLA Standard Bands.

All of the below will change with the EVLA, which can reach just about any frequency. The following is basically obsolete.

A total of 19 standard observing bands are defined at the VLA. All projects should specify one of these bands, even when frequencies will be modified. This ensures that various defaults at the VLA get set properly. Just pick one with similar properties. For VLBI, one of the ``V'' bands should be chosen.

The tables below describe the bands. The first show the band names along with the synthesizer settings. The column headings are the SCHED names (not necessarily the traditional names in use at the VLA) for these parameters. The second table gives the value that SCHED would want for the VLBI FIRSTLO parameter when using the standard setup. If the frequencies are modified, FIRSTLO would need to be altered. SCHED will insure that FIRSTLO agrees with the frequency that will be obtained with the settings used. The other columns in the second table show the range of sky frequencies covered by the VLA band. The observing frequencies must lie in these bands. Note that the first frequency is that of the edge converted to DC, and then to 600 MHz in the signal sent to the VLBI rack. The other end of the band can be a lower frequency if there is a net lower sideband at this point (the BBC's can be used in lower sideband mode to get a final net upper sideband).

The VLA band VQ will be changed a few months into 2001. The table below gives the frequencies for the new version. The old version was 80 MHz higher in frequency and missed the SiO line at 43.122 GHz. The current plan is to switch SCHED to the new VQ in January 2001, but have SCHED always write LO and IF cards in the VLA observe file for 43 GHz observing, even when using the standard band. After a few months in which any schedules made with the old scheme are flushed through the system, the VLA on-line system will be switch to the new standard. Some months after that, SCHED will stop writing the LO and IF cards for the new standard VQ band.

          VLA STANDARD BANDS - VLA SYNTHESIZER SETTINGS
VLABAND  VLAFEAB  VLAFECD  VLASYNA   VLASYNB   FLUKEA     FLUKEB  FEFILT
  CC      0.00      0.00    3860.1    3810.1  100.00000  200.00000  0000
  UU     19.60     19.60    3610.1    3660.1  100.00000  200.00000  0000
  KK     17.60     17.60    3860.1    3810.1  100.00000  200.00000  0000
  LL     -3.20     -3.20    3639.9    3560.1  100.00000  200.00000  0000
  XX     13.40     13.40    3939.9    3889.9  100.00000  200.00000  0000
  QQ     51.60     13.00    3689.9    3739.9  100.00000  200.00000  0000
  PP      0.00      0.00    -689.9    -710.1  115.83750  230.10000  1111
  44      0.00      0.00    -939.9    -939.9  112.91875  212.91875  0000
  4P      0.00      0.00    -939.9    -689.9  112.91875  215.83750  1111
  LP     -3.20      0.00    3639.9    -689.9  100.00000  215.83750  0101
  18     -3.20     -3.20    3839.9    3810.1  100.00000  200.00000  0000
  HH     -3.20     -3.20    3589.9    3639.9  115.10000  215.10000  0000
  VP      0.00      0.00    -689.9    -689.9  112.50000  212.50000  1111
  VL     -3.20     -3.20    3839.9    3839.9  100.00000  200.00000  0000
  VC      0.00      0.00    3960.1    3960.1  100.00000  200.00000  0000
  VX     13.00     13.00    3560.1    3560.1  100.00000  200.00000  0000
  VU     19.90     19.90    3510.1    3510.1  100.00000  200.00000  0000
  VK     17.50     17.50    3710.1    3710.1  100.00000  200.00000  0000
  VQ     51.60     13.00    3510.1    3510.1  100.00000  200.00000  0000

          VLA STANDARD BANDS - VLBI FIRSTLO and VLA BANDPASSES
VLABAND FIRSTLO A  FIRSTLO D         BANDPASS A           BANDPASS D
  CC     4260.10     4210.10     4860.10-  4910.10    4810.10-  4860.10
  UU    15589.90    15539.90    14989.90- 14939.90   14939.90- 14889.90
  KK    21860.10    21810.10    22460.10- 22510.10   22410.10- 22460.10
  LL      839.90      760.10     1439.90-  1489.90    1360.10-  1410.10
  XX     9060.10     9110.10     8460.10-  8410.10    8510.10-  8460.10
  QQ    42689.90    42739.90    43289.90- 43339.90   43339.90- 43389.90
  PP  -274.06250     -280.00   325.93750-350.93750     320.00-   345.00
  44  -526.98125  -526.98125    73.01875-123.01875   73.01875-123.01875
  4P  -526.98125  -274.06250    73.01875- 98.01875  325.93750-350.93750
  LP      839.90  -274.06250     1439.90-  1489.90  325.93750-350.93750
  18     1039.90     1010.10     1639.90-  1689.90    1610.10-  1660.10
  HH      805.00      855.00     1405.00-  1455.00    1455.00-  1505.00
  VP     -277.40     -277.40      322.60-   347.60     322.60-   347.60
  VL     1039.90     1039.90     1639.90-  1689.90    1639.90-  1689.90
  VC     4360.10     4360.10     4960.10-  5010.10    4960.10-  5010.10
  VX     9039.90     9039.90     8439.90-  8389.90    8439.90-  8389.90
  VU    15989.90    15989.90    15389.90- 15339.90   15389.90- 15339.90
  VK    21610.10    21610.10    22210.10- 22260.10   22210.10- 22260.10
  VQ    42510.10    42510.10    43110.10- 43160.10   43110.10- 43160.10
 Note that IF A and C are usually at the same frequency as are B and D.