Size: 5363
Comment:
|
Size: 10236
Comment:
|
Deletions are marked like this. | Additions are marked like this. |
Line 6: | Line 6: |
This page summarizes the present instrumentation at the 30m observatory. The current status is described on another [http://www.iram.es/IRAMES/mainWiki/TelescopeSystemStatus page]. | This page summarizes the '''present instrumentation''' installed at the 30m observatory. [[BR]] The current system '''status''' is described [http://www.iram.es/IRAMES/mainWiki/TelescopeSystemStatus here]. |
Line 12: | Line 13: |
==== A,B,C,D single pixel receivers ==== A maximum of four receivers, from the total of eight, can be used simultaneously. The following table summarizes the allowed combinations and some of the most important receiver characteristics. Plots of the receiver characteristics. |
|
Line 15: | Line 14: |
==== HERA 3x3 dual-polarisation 1.2mm array ==== HERA cannot be combined with other receivers; up to now not all frequencies have been pretuned. Hera has 18 pixels separated by 24". Local contact for HERA: Albrecht Sievers |
* Eight single pixel receivers A,B,C,D, and the 3x3 dual-polarisation HERA receiver are installed in the [http://www.iram.es/IRAMES/telescope/telescopeSummary/receiver6.html receiver cabin]. |
Line 18: | Line 16: |
||'''Rx''' ||'''Pol'''|| || || || || '''tuning range''' || '''Trx''' || '''IF''' || '''IF Bw''' || '''Gim''' || '''Remarks''' || || || || || || || || '''[GHz]''' || '''[K]''' || '''[GHz]''' || '''[GHz]''' || '''[dB]''' || || ||A100 || V || X || || X || || 80.0-115.5 || 60-80 || 1.5 || 0.5 || >20 || 1. || ||B100 || H || X || || || X || 81.0-115.5 || 60-85 || 1.5 || 0.5 || >20 || || ||C150 || V || || X || || X || 130-183 || 70-125 || 4 || 1 || 15-25 || || ||D150 || H || || X || X || || 130-183 || 80-125 || 4 || 1 || 08-17 || || ||A230 || V || X || || X || || 197-266 || 85-150 || 4 || 1 || || || ||B230 || H || X || || || X || 197-266 || 95-160 || 4 || 1 || || || ||C270 || V || || || || || 241-281 || 125-250 || 4 || 1 || || || ||D270 || H || || || || || 241-281 || 150-250 || 4 || 1 || || || ||HERA || H || || || || || 215-272 || 110-380 || 4 || 1 || || || ||HERA || V || || || || || 215-241 || 120-340 || 4 || 1 || || || |
* Four of the 8 A,B,C,D receivers can be used simultaneously. HERA cannot be combined with other receivers. * [http://www.iram.es/IRAMES/telescope/telescopeSummary/receiver3.html Plots of the receiver characteristics (taken 2000)] ||'''Rx''' ||#||'''Pol'''|||||||||| '''Rx combinations''' ||'''tuning range''' || '''Trx''' || '''IF''' || '''IF Bw''' || '''Gim''' || '''Rem.''' || || || || || || || || || ||'''[GHz]''' || '''[K]''' || '''[GHz]''' || '''[GHz]''' || '''[dB]''' || || ||A100 || 1|| V || X || || X || || ||(72-)80.0-115.5 || 60-80 || 1.5 || 0.5 || >20 || '''1. '''|| ||B100 || 1|| H || X || || || X || ||(72-)81.0-115.5 || 60-85 || 1.5 || 0.5 || >20 || '''1.'''|| ||C150 || 1|| V || || X || || X || ||130-183 || 70-125 || 4 || 1 || 15-25 || || ||D150 || 1|| H || || X || X || || ||130-183 || 80-125 || 4 || 1 || 08-17 || || ||A230 || 1|| V || X || || X || || ||197-266 || 85-150 || 4 || 1 || 12-17 || || ||B230 || 1|| H || X || || || X || ||197-266 || 95-160 || 4 || 1 || 12-17 || || ||C270 || 1|| V || || X || || X || ||241-281 || 125-250 || 4 || 1 || 10-20 || '''2.'''|| ||D270 || 1|| H || || X || X || || ||241-281 || 150-250 || 4 || 1 || 9-13 || '''2.'''|| ||HERA1 || 9|| H || || || || || X || 215-272 || 110-380 || 4 || 1 || ~10 || '''2.,3.'''|| ||HERA2 || 9|| V || || || || || X || 215-241 || 120-340 || 4 || 1 || ~10 || '''2.,3.'''|| '''Remarks:''' |
Line 35: | Line 42: |
1. 2x(3x3) pixel receiver with a 24" separation of the pixels. Equipped with a derotator allowing to follow a source in the sky maintaining the same "footprint". | 1. [http://www.iram.es/IRAMES/mainWiki/HeraWebPage More information on HERA ] [#beginOfPage Back to top] |
Line 37: | Line 46: |
Table | |
Line 39: | Line 47: |
local contact for bolometers: Stephane Leon | Two large field bolometer cameras are installed: '''MAMBO1''' with 37 pixels, and '''MAMBO2''' with 117 pixels. Usually MAMBO2 is in use. Both cameras work at 1.2mm wavelength, the HPBW is 11 arcsec, pixel spacing is 20 arcsec, and the sensitivity is 1.5mJy. This is the rms after 10 minutes integration (normal bolometric conditions) with skynoise removal. See [http://www.iram.es/IRAMES/mainWiki/MamboWebPage the MAMBO page for details.] |
Line 41: | Line 49: |
== Efficiencies and Half-power beam width == Below you find the most recent values for the forward and beam efficiencies. We have also compiled the value of the efficiencies in the past . |
[#beginOfPage Back to top] |
Line 44: | Line 51: |
Here you can find the plot with the most recently measured beam efficiencies. | == Telescope efficiencies and beam widths == |
Line 46: | Line 53: |
Table | * Below you find the most recent values for the forward and beam efficiencies. We have also compiled the [http://www.iram.es/IRAMES/telescope/telescopeSummary/effi_history.html value of the efficiencies in the past]. |
Line 48: | Line 55: |
1) The HPBW can be well fit by: HPBW('') = 2460/freq(GHz). '' | * Here you can find the [http://www.iram.es/IRAMES/telescope/telescopeSummary/beam_effis.html plot of efficiencies measured in 2000]. A more recent compilation can be found in the Annual Report 2007. |
Line 50: | Line 57: |
''2) The data can be well fit by a Ruze function B_eff = 1.2 epsilon exp[-(4pi R sigma/ lambda)^2] with sigma being the rms value of the telescope optics deformations, R the reduction factor for a steep main reflector, epsilon the aperture efficieny of the perfect telescope and lambda the wavelength in mm. The data can be fit by R*sigma = 0.07 and epsilon = 0.69. The aperture efficiency of the 30-m telescope can be obtained using eta_a=B_eff*0.79 '' | || freq || HPBW || Beff || S/TA* || Feff || || (GHz) || (arcsec) || (%) || (Jy/K) || (%) || || || (1) || (2) || (3) || (4) || ||72 (extrapolated) || 34 || 79 || 6.0 || 95 || ||77 (extrapolated) || 32 || 79 || 6.0 || 95 || ||86 ||29 || 78 || 6.0 || 95 || ||110 || 22 || 75 || 6.3 || 95 || ||145 || 17 || 69 || 6.7 || 93 || ||170 || 14.5 || 65 || 7.1 || 93 || ||210 || 12 || 57 || 7.9 || 91 || ||235 || 10.5 || 52 || 8.7 || 91 || ||260 || 9.5 || 46 || 9.5 || 88 || ||279 || 9 || 42 || 10.4 || 88 || |
Line 52: | Line 71: |
''3) For a Gaussian source and beam size, and a source which is much smaller than the beam, S(Jy)/T_mb(K)=8.18E-7*theta(")^2*nu(GHz)^2 (Rohlfs & Wilson, Tools of Radioastronomy (2. ed., Eq. 8.20). Using the approximation in 1) yields for the 30-m telescope S/T_mb=4.95 Jy/K. S/T_A* is obtained by multiplying 4.95 J/K with F_eff/B_eff '' | 1. The half power beam width, HPBW, can be well fitted by: HPBW/arcsec = 2460/freq/GHz. |
Line 54: | Line 73: |
''Table '' | 1. Main beam efficiency Beff. The data can be well fit by a Ruze function Beff = 1.2 epsilon exp[-(4pi R sigma/ lambda)^2] with sigma being the rms value of the telescope optics deformations, R the reduction factor for a steep main reflector, epsilon the aperture efficieny of the perfect telescope and lambda the wavelength in mm. The data can be fit by R*sigma = 0.07 and epsilon = 0.69. The aperture efficiency of the 30-m telescope can be obtained using eta_a=B_eff*0.79 |
Line 56: | Line 75: |
''4) The values for F_eff are valid after the 12th of December 2000 when a new reflecting ring was put around the secondary mirror. The moon efficiencies are equal to forward efficiencies (Kramer et al. 1997). '' | 1. Point source sensitivity S/T_A*. For a Gaussian source and beam size, and a source which is much smaller than the beam, S(Jy)/T_mb(K)=8.18E-7*theta(")**2*nu(GHz)**2 (Rohlfs & Wilson, Tools of Radioastronomy (2. ed., Eq. 8.20). Using the approximation in 1) yields for the 30-m telescope S/T_mb=4.95 Jy/K. S/T_A* is obtained by multiplying 4.95 J/K with F_eff/B_eff. 1. The values for F_eff are valid after the 12th of December 2000 when a new reflecting ring was put around the secondary mirror. The moon efficiencies are equal to forward efficiencies (Kramer et al. 1997). [#beginOfPage Back to top] |
Line 59: | Line 81: |
=== Spectrometers === Table |
|
Line 62: | Line 82: |
=== Bolometer backends === == Spectral Line Observing Modes == |
|| || Type || Resolution || Bandwidth || Receiver (width mode) || Remark || || '''1 MHz''' || Filterbank || 1 MHz || 4x256 MHz, 2x512 MHz, or, 1x1GHz || A100, B100 (narrow), A230, B230, C150, D150, C270, D270 (narrow or wide) || (1) || || '''4 MHz''' || Filterbanks || 4 MHz || 9x1GHz || either HERA1 or HERA2 (wide), all other SIS receivers (wide) except 3mm || (2) || || '''WILMA''' || Autocorrelator || 2 MHz || 18x930 MHz || HERA (wide) || (3) || || '''VESPA''' || Autocorrelator || 3.3 kHz-1.25 MHz || 10-512 MHz || all SIS receives incl. HERA (narrow) || (4) || || '''XPOL''' || VESPA || 40kHz-1.25MHz || 120-640MHz || A100 and B100 (narrow) || (5) || || '''ABBA1''' || || || || || (6) || || '''ABBA2''' || || || || || (6) || 1. '''1MHz FB''': max 4 parts; series parallel or mixed mode possible; using the filterbanks with 1GHz bandwidth excludes the use of the AC or the 100 MHz FB with the same rx. The FB can be shifted in multiples of 32 MHz from the center frequency of the connected rx. 1. '''4MHz FB''': max 9 parts; use of the 4 MHz FBs excludes the use of the AC on the same receiver. Frequency switching not available. While the channel spacing is 4MHz, the 3dB width is 5.4 MHz and the noise equivalent width is 6.5 MHz 1. '''WILMA''': [http://www.iram.fr/IRAMFR/TA/backend/veleta/wilma/index.htm The Wideband Line Multiple Autocorrelator] 1. '''VESPA''': Up to 18000 channels. In connection with HERA (9 pixels) the following combinations of resolution (kHz) and bandwidth (MHz) are possible: (20/40), (40,80), (80, 160), (320,320), (1250, 640); [http://www.iram.es/IRAMES/otherDocuments/manuals/vespa_ug.ps VESPA User Guide (2002)], [http://www.iram.es/IRAMFR/ARN/dec02/node6.html Summary in IRAM Newsletter No. 54 (Dec 2002)], local contact: G. Paubert 1. Line and continuum polarimetry is possible at the 30m using a new type of IF polarimeter designated XPOL. The central feature of XPOL is the correlator VESPA where the IF signals from two orthogonally polarized receivers are cross correlated to determine the four Stokes parameters. A manual is in preparation, contact: C. Thum 1. ABBA1 and ABBA2 are the bolometer backends, i.e. dedicated PCs connected to the bolometers. [#beginOfPage Back to top] == Control System == The 30-m telescope runs under the New Control System (NCS), see: . [http://www.iram.es/IRAMES/ncs30m/ NCS documentation] [http://mrt-lx1/mainWiki/ Wiki with up-to-date Notes on NCS] Observing modes and source offsets in: * Projection "Radio" (same offsets as in old CS) in Equatorial J2000.0 * "true angle" horizontal * Nasmyth (receiver offsets) [#beginOfPage Back to top] == Observing Modes == || Observing mode || total power || chopping || position switching || beam switching || frequency switching || || '''Calibrate''' (Heterodyne) || X || || || || || || '''Pointing''' || || X || || || || || '''Focus''' || || X || || || || || '''Tip''' (Skydip) || || X || || || || || '''Track''' || X || || || || X || || '''ON-OFF''' || || || X || X || || || '''OTF''' (Heterodyne) || || || X || || X || || '''OTF''' (Bolometer) || || || || X || || || '''VLBI''' || || || || || || * '''Pointing''': Using nearby (within 10 degree) pointing sources, <1" accuracy can be obtained; with absolute ("blind") pointing, the accuracy is about 2" rms, the receivers are aligned within 1.7" (see the [http://www.iram.es/IRAMES/mainWiki/TelescopeSystemStatus Telescope Status page] for current values). Checking the pointing and alignment (using e.g. a planet) is the responsibility of the observer. * '''Focus''': residual errors of <1mm may need correction. There are systematic differences of upto 0.6mm in the focus of the different receivers (cf. [http://www.iram.es/IRAMES/mainWiki/TelescopeSystemStatus Telescope Status page]). Check focus at least at after sunrise and sunset. |
Line 65: | Line 135: |
* '''Wobbling secondary''': max. 240" throw at 0.25 Hz, standard phase duration 0.5 Hz. * '''Frequency switching''': max. 45 km/s throw at max. 0.5 Hz., with 100 kHz filters and autocorrelator only * '''On the fly mapping''': Works with all receiver and backends, typical dump rate 0.5-1 Hz |
* '''Beam switching''' with wobbling secondary: max. 240" throw at 0.25 Hz, standard phase duration 0.5 Hz. * '''Frequency switching''': max. 45 km/s throw at max. 0.5 Hz., with autocorrelators only. * '''On the fly mapping (Heterodyne)''': Works with all receiver and backends, typical dump rate 0.5-1 Hz |
Line 69: | Line 139: |
* '''Pointing''': Using nearby (within 10 degree) pointing sources, <1" accuracy can be obtained; with absolute ("blind") pointing, the accuracy is <4", the receivers are usually aligned within 2". Checking the pointing and alignment (using e.g. a planet) is the responsibility of the observer. * '''Focus''': residual errors of <1mm may need correction. There may be systematic differences (<0.4") in the focus of the different receivers. Check focus at least at after sunrise and sunset. |
[#beginOfPage Back to top] Old [http://www.iram.es/IRAMES/telescope/telescopeSummary/telescope_summary.html Telescope System Summary page] This is page http://www.iram.es/IRAMES/mainWiki/TelescopeSystemSummary moderated by Carsten Kramer |
This page summarizes the present instrumentation installed at the 30m observatory. BR The current system status is described [http://www.iram.es/IRAMES/mainWiki/TelescopeSystemStatus here].
Frontends
Heterodyne Receivers
Eight single pixel receivers A,B,C,D, and the 3x3 dual-polarisation HERA receiver are installed in the [http://www.iram.es/IRAMES/telescope/telescopeSummary/receiver6.html receiver cabin].
- Four of the 8 A,B,C,D receivers can be used simultaneously. HERA cannot be combined with other receivers.
[http://www.iram.es/IRAMES/telescope/telescopeSummary/receiver3.html Plots of the receiver characteristics (taken 2000)]
Rx |
# |
Pol |
Rx combinations |
tuning range |
Trx |
IF |
IF Bw |
Gim |
Rem. |
||||
|
|
|
|
|
|
|
|
[GHz] |
[K] |
[GHz] |
[GHz] |
[dB] |
|
A100 |
1 |
V |
X |
|
X |
|
|
(72-)80.0-115.5 |
60-80 |
1.5 |
0.5 |
>20 |
1. |
B100 |
1 |
H |
X |
|
|
X |
|
(72-)81.0-115.5 |
60-85 |
1.5 |
0.5 |
>20 |
1. |
C150 |
1 |
V |
|
X |
|
X |
|
130-183 |
70-125 |
4 |
1 |
15-25 |
|
D150 |
1 |
H |
|
X |
X |
|
|
130-183 |
80-125 |
4 |
1 |
08-17 |
|
A230 |
1 |
V |
X |
|
X |
|
|
197-266 |
85-150 |
4 |
1 |
12-17 |
|
B230 |
1 |
H |
X |
|
|
X |
|
197-266 |
95-160 |
4 |
1 |
12-17 |
|
C270 |
1 |
V |
|
X |
|
X |
|
241-281 |
125-250 |
4 |
1 |
10-20 |
2. |
D270 |
1 |
H |
|
X |
X |
|
|
241-281 |
150-250 |
4 |
1 |
9-13 |
2. |
HERA1 |
9 |
H |
|
|
|
|
X |
215-272 |
110-380 |
4 |
1 |
~10 |
2.,3. |
HERA2 |
9 |
V |
|
|
|
|
X |
215-241 |
120-340 |
4 |
1 |
~10 |
2.,3. |
Remarks:
- Using a special external LO, frequencies down to 77 GHz can be measured with good sideband rejection. For frequencies below 77 GHz, the sideband recection becomes weaker, and the sideband ratio reaches unity at 72 GHz
- Noise increasing with frequency
[http://www.iram.es/IRAMES/mainWiki/HeraWebPage More information on HERA ]
[#beginOfPage Back to top]
Bolometers
Two large field bolometer cameras are installed: MAMBO1 with 37 pixels, and MAMBO2 with 117 pixels. Usually MAMBO2 is in use. Both cameras work at 1.2mm wavelength, the HPBW is 11 arcsec, pixel spacing is 20 arcsec, and the sensitivity is 1.5mJy. This is the rms after 10 minutes integration (normal bolometric conditions) with skynoise removal. See [http://www.iram.es/IRAMES/mainWiki/MamboWebPage the MAMBO page for details.]
[#beginOfPage Back to top]
Telescope efficiencies and beam widths
Below you find the most recent values for the forward and beam efficiencies. We have also compiled the [http://www.iram.es/IRAMES/telescope/telescopeSummary/effi_history.html value of the efficiencies in the past].
Here you can find the [http://www.iram.es/IRAMES/telescope/telescopeSummary/beam_effis.html plot of efficiencies measured in 2000]. A more recent compilation can be found in the Annual Report 2007.
freq |
HPBW |
Beff |
S/TA* |
Feff |
(GHz) |
(arcsec) |
(%) |
(Jy/K) |
(%) |
|
(1) |
(2) |
(3) |
(4) |
72 (extrapolated) |
34 |
79 |
6.0 |
95 |
77 (extrapolated) |
32 |
79 |
6.0 |
95 |
86 |
29 |
78 |
6.0 |
95 |
110 |
22 |
75 |
6.3 |
95 |
145 |
17 |
69 |
6.7 |
93 |
170 |
14.5 |
65 |
7.1 |
93 |
210 |
12 |
57 |
7.9 |
91 |
235 |
10.5 |
52 |
8.7 |
91 |
260 |
9.5 |
46 |
9.5 |
88 |
279 |
9 |
42 |
10.4 |
88 |
- The half power beam width, HPBW, can be well fitted by: HPBW/arcsec = 2460/freq/GHz.
- Main beam efficiency Beff. The data can be well fit by a Ruze function Beff = 1.2 epsilon exp[-(4pi R sigma/ lambda)^2] with sigma being the rms value of the telescope optics deformations, R the reduction factor for a steep main reflector, epsilon the aperture efficieny of the perfect telescope and lambda the wavelength in mm. The data can be fit by R*sigma = 0.07 and epsilon = 0.69. The aperture efficiency of the 30-m telescope can be obtained using eta_a=B_eff*0.79
Point source sensitivity S/T_A*. For a Gaussian source and beam size, and a source which is much smaller than the beam, S(Jy)/T_mb(K)=8.18E-7*theta(")**2*nu(GHz)**2 (Rohlfs & Wilson, Tools of Radioastronomy (2. ed., Eq. 8.20). Using the approximation in 1) yields for the 30-m telescope S/T_mb=4.95 Jy/K. S/T_A* is obtained by multiplying 4.95 J/K with F_eff/B_eff.
- The values for F_eff are valid after the 12th of December 2000 when a new reflecting ring was put around the secondary mirror. The moon efficiencies are equal to forward efficiencies (Kramer et al. 1997).
[#beginOfPage Back to top]
Backends
|
Type |
Resolution |
Bandwidth |
Receiver (width mode) |
Remark |
1 MHz |
Filterbank |
1 MHz |
4x256 MHz, 2x512 MHz, or, 1x1GHz |
A100, B100 (narrow), A230, B230, C150, D150, C270, D270 (narrow or wide) |
(1) |
4 MHz |
Filterbanks |
4 MHz |
9x1GHz |
either HERA1 or HERA2 (wide), all other SIS receivers (wide) except 3mm |
(2) |
WILMA |
Autocorrelator |
2 MHz |
18x930 MHz |
HERA (wide) |
(3) |
VESPA |
Autocorrelator |
3.3 kHz-1.25 MHz |
10-512 MHz |
all SIS receives incl. HERA (narrow) |
(4) |
XPOL |
VESPA |
40kHz-1.25MHz |
120-640MHz |
A100 and B100 (narrow) |
(5) |
ABBA1 |
|
|
|
|
(6) |
ABBA2 |
|
|
|
|
(6) |
1MHz FB: max 4 parts; series parallel or mixed mode possible; using the filterbanks with 1GHz bandwidth excludes the use of the AC or the 100 MHz FB with the same rx. The FB can be shifted in multiples of 32 MHz from the center frequency of the connected rx.
4MHz FB: max 9 parts; use of the 4 MHz FBs excludes the use of the AC on the same receiver. Frequency switching not available. While the channel spacing is 4MHz, the 3dB width is 5.4 MHz and the noise equivalent width is 6.5 MHz
WILMA: [http://www.iram.fr/IRAMFR/TA/backend/veleta/wilma/index.htm The Wideband Line Multiple Autocorrelator]
VESPA: Up to 18000 channels. In connection with HERA (9 pixels) the following combinations of resolution (kHz) and bandwidth (MHz) are possible: (20/40), (40,80), (80, 160), (320,320), (1250, 640); [http://www.iram.es/IRAMES/otherDocuments/manuals/vespa_ug.ps VESPA User Guide (2002)], [http://www.iram.es/IRAMFR/ARN/dec02/node6.html Summary in IRAM Newsletter No. 54 (Dec 2002)], local contact: G. Paubert
- Line and continuum polarimetry is possible at the 30m using a new type of IF polarimeter designated XPOL. The central feature of XPOL is the correlator VESPA where the IF signals from two orthogonally polarized receivers are cross correlated to determine the four Stokes parameters. A manual is in preparation, contact: C. Thum
- ABBA1 and ABBA2 are the bolometer backends, i.e. dedicated PCs connected to the bolometers.
[#beginOfPage Back to top]
Control System
The 30-m telescope runs under the New Control System (NCS), see:
[http://www.iram.es/IRAMES/ncs30m/ NCS documentation] [http://mrt-lx1/mainWiki/ Wiki with up-to-date Notes on NCS]
Observing modes and source offsets in:
- Projection "Radio" (same offsets as in old CS) in Equatorial J2000.0
- "true angle" horizontal
- Nasmyth (receiver offsets)
[#beginOfPage Back to top]
Observing Modes
Observing mode |
total power |
chopping |
position switching |
beam switching |
frequency switching |
Calibrate (Heterodyne) |
X |
|
|
|
|
Pointing |
|
X |
|
|
|
Focus |
|
X |
|
|
|
Tip (Skydip) |
|
X |
|
|
|
Track |
X |
|
|
|
X |
ON-OFF |
|
|
X |
X |
|
OTF (Heterodyne) |
|
|
X |
|
X |
OTF (Bolometer) |
|
|
|
X |
|
VLBI |
|
|
|
|
|
Pointing: Using nearby (within 10 degree) pointing sources, <1" accuracy can be obtained; with absolute ("blind") pointing, the accuracy is about 2" rms, the receivers are aligned within 1.7" (see the [http://www.iram.es/IRAMES/mainWiki/TelescopeSystemStatus Telescope Status page] for current values). Checking the pointing and alignment (using e.g. a planet) is the responsibility of the observer.
Focus: residual errors of <1mm may need correction. There are systematic differences of upto 0.6mm in the focus of the different receivers (cf. [http://www.iram.es/IRAMES/mainWiki/TelescopeSystemStatus Telescope Status page]). Check focus at least at after sunrise and sunset.
Position switching: only relative OFF positions possible (radio projection offsets).
Beam switching with wobbling secondary: max. 240" throw at 0.25 Hz, standard phase duration 0.5 Hz.
Frequency switching: max. 45 km/s throw at max. 0.5 Hz., with autocorrelators only.
On the fly mapping (Heterodyne): Works with all receiver and backends, typical dump rate 0.5-1 Hz
Polarimetry: using VESPA as an IF polarimeter
[#beginOfPage Back to top]
Old [http://www.iram.es/IRAMES/telescope/telescopeSummary/telescope_summary.html Telescope System Summary page]
This is page http://www.iram.es/IRAMES/mainWiki/TelescopeSystemSummary moderated by Carsten Kramer