UKIDSS LAS inter-waveband cadence
The UKIDSS LAS data is nominally taken with MSBs lasting 1hr in duration
either Y and J or H and K in the same MSB. Within an MSB each of the two
wavebands is observed continuously for half the time. Each MSB
consists of a series of complete 4-pointing Tiles. Typically 4 to
5 tiles are observed in two bands per hourly MSB.
The plots below show
the difference is time between wavebands for DR1. DR1 and DR1+ are
shown separately.
DR1 distributions
[could also do EDR and tabulate some
centiles]
Some features to note are:
- Y is observed before J with a median interval of around 25mins
and 95% within 40mins. [see the differential Y-J plot with median -0.42hrs]
- Similarly H is observed before K with a median interval of around 25mins
and 95% within 40mins. [see the differential Y-J plot with median -0.42hrs]
- The median interval between the YJ and HK observations is
2.20hrs(0.09days) with 45% of the OBs pairs separated by more than
a day. i.e. 55% of YJ and HK OBs accur on the same night.
35% of the HK OBs are more than a day earlier that the
YJ OBs and 15% are more than a day after the YJ OBs.
- The UT distribution of the OBs is similar in all wavebands.
DR1 plots
DR1plus plots
Richard G. McMahon
<rgm@ast.cam.ac.uk>
Last modified: Thu Jan 18 16:54:07 2007