Based on UFTI measurements between early 2000 and March 2002. These data were used to draw conclusions for the design of UKIDSS execution strategies.

Columns are UT hours (one hour bins).

Rows are

  1. H vs J
  2. K vs H
  3. K vs J

Magnitude scales

J: 13-17

H: 12.5-15

K: 12-14.5

Not enough data

Comments on Features

  • For a given filter pair, correlations are essentially similar (to plus or minus a few tenths of a magnitude) from one hour to the next, though the points fall on different parts of the correlation.
  • For correlations involving the J filter (top and bottom rows), the start and end of the night have larger scatter – most obviously at the start (top left and bottom left of the table).
  • The H vs. K scatter appears to be independent of time of night.
  • Centre of gravity of the point groups moves from lower left to upper right as sky brightness decreases through the night.

A Adamson, Summer 2004