Universe appears to be expanding at an increasing rate. What measurements were performed to support this idea? My current understanding is that in general redshift of distant stars/galaxies is increasing with time. So to me the measurements may look like this: We choose one star, measure its redshift, say it would be 1 Hz. Then one year later we measure the redshift of the same star and it would be, say, 2 Hz. We perform the same measurements on many stars and if most of them have increased their redshift it suggest that in general the universe expansion increases. Is it so or my understanding is not correct?