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information_for_astronomers:rx:p200mm
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Table of Contents
18cm/21cm prime focus receiver (1270-1730 MHz)
This system is used for sensitive continuum, VLBI (especially 18cm), spectroscopy, and pulsar observations. Be aware, that this band may be influenced by RFI. It can be used in combination with a multi channel polarimeter of 8x4 MHz band width, and a total 40 MHz wide channel.
Calibration Information
| Frequency [GHz] | Channel | Polarisation | Tcal [K] | Tsys [K] | Sensitivity [K/Jy] | SEFD [Jy] | Aperture Eff. [%] | TMB/S [K/Jy] | Main Beam Eff. [%] | FWHM [arcsec] | Last update |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 1.400 | A | LCP | 1.2 | 21 | 1.55 | 14 | 54 | 2.0 | 75 | 553 | June 2008 |
| 1.400 | B | RCP | 1.3 | 27 | 1.55 | 18 | 53 | 2.0 | 74 | 553 | June 2008 |
| 1.660 | A | LCP | 1.2 | 26 | 1.55 | 17 | 53 | 2.0 | 76 | 473 | June 2008 |
| 1.660 | B | RCP | 1.4 | 27 | 1.55 | 18 | 52 | 2.0 | 75 | 473 | June 2008 |
| normalized Gain curve (G = A0 + A1·Elv + A2·Elv2) | Observed in | confirmed | ||
|---|---|---|---|---|
| A0 = 1.0 | A1 = 0.0 | A2 = 0.0 | Feb 2007 | |
Comments:
- Strong interferences can occur in this frequency regime, eg. between 1.50 and 1.64 GHz!
Version description for OBSINP
| RX Name | Wavelength [cm] | Frequency (center) [GHz] | Nr. of Horns |
|---|---|---|---|
| P200mm 4-Box (1.29-1.73 GHz) | 21.0-18.0 | 1.29-1.73 | 1 |
| Version: | Comment | ||
| 1. Cont./Line: 1,29-1,43 GHz (BW: 100 MHz) | 21cm, 2 channel continuum/line version | ||
| 2. Cont./Line: 1,59-1.725 GHz (BW: 100 MHz) | 18cm, 2 channel continuum/line version | ||
| 3. Pulsar 1,29-1,43 GHz (BW: 100 MHz) | 21cm, Pulsar version | ||
| 4. Pulsar: 1,59-1.725 GHz (BW: 100 MHz) | 18cm, Pulsar version | ||
| 5. VLBI: 1,29-1,43 GHz (BW: 100 MHz) | 21cm VLBI version | ||
| 6. VLBI: 1,59-1.725 GHz (BW: 100 MHz) | 18cm VLBI version | ||
| 7. Polarimeter: 1,29-1,43 GHz (BW: 100 MHz) | 21cm, 8 channel polarimeter | ||
| 8. Polarimeter: 1,59-1.725 GHz (BW: 100 MHz) | 18cm, 8 channel polarimeter | ||
| Horn offsets [arcsec] | -874.4,971.1 | ||
Channel assignment in the MBFITS data files
Note that the narrow line and VLBA IF channels are usually only available when the specific line version of the receiver was selected. In addition for most receivers with narrow line channels the cables at the patch board need to be connected by the receiver group.
To select different channel numbers in OBSINP, the online plot, or the toolbox the numbers have to be specified like c(1)+c(2) to add channel 1 and 2. E.g. channel 1 and 2 contain the LCP and RCP broadband channels, then "OnlPlot pen='c(1)+c(2)'" or "toolbox use='c(1)+c(2)'" will select these channels. In OBSINP the pen can be directly specified in the receiver selection menu.
Abbreviations:
SB: narrow band channel (Schmalband-Kanal), 100 MHz band width
BB: digital broad band channel (Breitband-Kanal), band width varies for different receivers
VLBA: VLBA IF, 500 MHz band width
BW: band width
TP: total power
| 18/21cm PFK (Multi-RX-Box I, 2 channel cont/line, Pulsar and VLBI versions) | |||
|---|---|---|---|
| Channel | IF | Pol. | Comment |
| 1 | SB | LCP | TP A |
| 2 | SB | RCP | TP B |
| 3 | SB | cross | cos AB |
| 4 | SB | cross | sin AB |
| 18/21cm PFK (Multi-RX-Box I, multi channel polarimeter version) | |||
|---|---|---|---|
| Channel | IF | Pol. | Comment |
| 1 | SB | LCP | center=freq-14MHz, BW=4MHz, TP A |
| 2 | SB | RCP | center=freq-14MHz, BW=4MHz, TP B |
| 3 | SB | cross | center=freq-14MHz, BW=4MHz, cos AB |
| 4 | SB | cross | center=freq-14MHz, BW=4MHz, sin AB |
| 5 | SB | LCP | center=freq-10MHz, BW=4MHz, TP A |
| 6 | SB | RCP | center=freq-10MHz, BW=4MHz, TP B |
| 7 | SB | cross | center=freq-10MHz, BW=4MHz, cos AB |
| 8 | SB | cross | center=freq-10MHz, BW=4MHz, sin AB |
| 9–28 | … | … | continues in 4MHz steps until |
| 29 | SB | LCP | center=freq+14MHz, BW=4MHz, TP A |
| 30 | SB | RCP | center=freq+14MHz, BW=4MHz, TP B |
| 31 | SB | cross | center=freq+14MHz, BW=4MHz, cos AB |
| 32 | SB | cross | center=freq+14MHz, BW=4MHz, sin AB |
| last 4 channels contain the total IF | |||
| 33 | SB | LCP | BW=40MHz, TP A |
| 34 | SB | RCP | BW=40MHz, TP B |
| 35 | SB | cross | BW=40MHz, cos AB |
| 36 | SB | cross | BW=40MHz, sin AB |
Spectroscopy modes and resolution
| BW | nchan | nu | Df | Dv | dv |
|---|---|---|---|---|---|
| MHz | MHz | kHz | km/s | km/s | |
| 100 | 32768 | 1300 | 3.1 | 0.704 | 0.816 |
| 100 | 32768 | 1320 | 3.1 | 0.693 | 0.804 |
| 100 | 32768 | 1340 | 3.1 | 0.683 | 0.792 |
| 100 | 32768 | 1360 | 3.1 | 0.673 | 0.780 |
| 100 | 32768 | 1380 | 3.1 | 0.663 | 0.769 |
| 100 | 32768 | 1400 | 3.1 | 0.653 | 0.758 |
| 100 | 32768 | 1420 | 3.1 | 0.644 | 0.747 |
| 100 | 32768 | 1440 | 3.1 | 0.635 | 0.737 |
| 100 | 32768 | 1600 | 3.1 | 0.572 | 0.663 |
| 100 | 32768 | 1620 | 3.1 | 0.565 | 0.655 |
| 100 | 32768 | 1640 | 3.1 | 0.558 | 0.647 |
| 100 | 32768 | 1660 | 3.1 | 0.551 | 0.639 |
| 100 | 32768 | 1680 | 3.1 | 0.545 | 0.632 |
| 100 | 32768 | 1700 | 3.1 | 0.538 | 0.624 |
| 100 | 32768 | 1720 | 3.1 | 0.532 | 0.617 |
BW … band width
nchan … number of spectral channels
nu … center frequency
Df … Channel separation (in frequency)
Dv … Channel separation (in velocity)
dv … Velocity resolution (dv=1.16*Dv)
Tcal measurements
Note that although the lines continue it is not possible to observe at frequencies between 1425 MHz and 1560 MHz.
information_for_astronomers/rx/p200mm.1382362621.txt.gz · Last modified: 2013/10/21 15:37 by bwinkel
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