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||'''Rx''' ||'''Pol'''||   || || || || ||'''tuning range''' || '''Trx''' || '''IF''' || '''IF Bw''' || '''Gim''' || '''Rem.''' ||
|| || || || || || || ||'''[GHz]''' || '''[K]''' || '''[GHz]''' || '''[GHz]''' || '''[dB]''' || ||
||A100 || V || X || || X || || ||(72-)80.0-115.5 || 60-80 || 1.5 || 0.5 || >20 || '''1. '''||
||B100 || H || X || || || X || ||(72-)81.0-115.5 || 60-85 || 1.5 || 0.5 || >20 || '''1.'''||
||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 || 12-17 || ||
||B230 || H || X || || || X || ||197-266 || 95-160 || 4 || 1 || 12-17 || ||
||C270 || V || || X || || X || ||241-281 || 125-250 || 4 || 1 || 10-20 || '''2.'''||
||D270 || H || || X || X || || ||241-281 || 150-250 || 4 || 1 || 9-13 || '''2.'''||
||HERA1 || H || || || || || X || 215-272 || 110-380 || 4 || 1 || ~10 || '''2.,3.'''||
||HERA2 || V || || || || || X || 215-241 || 120-340 || 4 || 1 || ~10 || '''2.,3.'''||
||'''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.'''||


||'''Rx''' ||#||'''Pol'''|| || || || || ||'''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.'''||

Anchor(beginOfPage)


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].

TableOfContents(4)

Frontends

Heterodyne Receivers

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.

Rx

#

Pol

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:

  1. 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
  2. Noise increasing with frequency
  3. [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

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

  1. The half power beam width, HPBW, can be well fitted by: HPBW/arcsec = 2460/freq/GHz.
  2. 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
  3. 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.

  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).

[#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)

VESPA

Autocorrelator

3.3 kHz-1.25 MHz

10-512 MHz

all SIS receives incl. HERA (narrow)

(3)

XPOL

VESPA

40kHz-1.25MHz

120-640MHz

A100 and B100 (narrow)

(4)

ABBA1

(5)

ABBA2

(5)

  1. 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.
  2. 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
  3. 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)], local contact: G. Paubert

  4. 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
  5. 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:

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

TelescopeSystemSummary (last edited 2009-07-07 13:46:21 by visitor4)