Current and Future CMB Experiments

Since the discovery of a statistical anisotropy four years ago by the COBE satellite, there has been a great increase in the number of ground and balloon-based measurements of CMB anisotropy. Many groups around the world have been engaged in projects which aim to detect individual features in the CMB, and to establish their statistical properties. Table 1 lists all of the major experiments in the field and includes links to their home pages. The focus of these has tended to be towards smaller angular scales than measured by COBE, and this holds with it the exciting prospect of being able to detect structure in the primordial power spectrum.

Table 1: The main CMB experiments with links to their WWW home pages where available

Space based	COBE [20 ]
	Planck [69 ]
	MAP [56 ]
Ground based	Tenerife [93 ]
	South Pole [87 ]
	Saskatoon [79 ]
	CAT [15 ]
	ATCA [3 ]
	Python [71 ]
	OVRO [66 ]
	SuZIE [90 ]
	Jodrell Bank [43 ]
	IAC Bartol [42 ]
	White Dish [98 ]
	Viper [95 ]
	COBRA [21 ]
	MAT [57 ]
	DASI [23 ]
	VSA [96 ]
	CBI [16 ]
	POLAR
	Brown/Wisc polarization [19 ]
Balloon Borne	FIRS [30 ]
	ARGO [2 ]
	MAX [58 ]
	BEAST [8 ]
	MSAM [60 ]
	BAM [5 ]
	ACE [1 ]
	QMAP [72 ]
	Boomerang [11 ]
	MAXIMA [59 ]
	Top Hat [94 ]

A summary of the properties and results of several experiments, covering the period through to 1996, is given in Lasenby & Hobson [50 ]. Since that time, i.e. in the last year, there have been significant developments with regard to a number of experiments, and we concentrate on these new results here. Table 2 shows in a convenient form the main parameters of several recent experiments.

Table 2: Some recent CMB anisotropy measurements.

Experiment	Type	Beamwidth/	$ν$ (GHz)
		Beamthrow (°)
DMR-COBE	Satellite	7	31, 53, 90
Tenerife	Ground	5/8	10, 15, 33
MIT/FIRS	Balloon	3.8	180 + 3 higher
ACME/HEMT	Ground	1.5/2.1	30/40
MAX	Balloon	0.5/1.0	110, 180, 270, 360
MSAM	Balloon	0.5/0.6	180 + 3 higher
White dish	Ground	0.18/0.47	90
Python	Ground	0.75/2.75	90
Saskatoon	Ground	1.5/2.45	26–36
ARGO	Balloon	0.9/1.8	150 + 3 higher
CAT	Ground	0.25	13–16
OVRO	Ground	0.1–0.4	14.5 + 32
IAC-Bartol	Ground	2	91–272

5 Current and Future CMB Experiments