Table 1.

Large radio surveys

Survey	Frequency, MHz	Sky coverage	Area, deg2	Resolution, arcsec	Sensitivity, (5σ)		Sources per deg2
					K	mJy beam−1
WENSS	325	δ > +30°	10,300	54 × 54 cosec |δ|	60	15	21
SUMSS	843	δ < −30°	10,300	43 × 43 cosec |δ|	4.7	5	37
FIRST	1,400	NGP	>5,000	5	25	1	90
NVSS	1,400	δ > −40°	33,900	45	0.8	2.5	54

NGP, north galactic pole.