The MIGHTEE observing plan consists of two-tiers. A mid-tier and a deep-tier. 

Deep-tier

The deep tier will be done commensally with the LADUMA project (deep HI emission).  LADUMA will observe one primary beam of MeerKAT for 5000 hours, with the time distributed over two bands: L-band (0.9 - 1.67 GHz) and UHF band (0.58 - 1.015 GHz).  The observation will be centred on ECDF-S with a field of view that varies from 0.9 sq deg at the high frequency end to 5.4 sq degrees at the low frequency end. 

Mid-tier

The MIGHTEE mid-tier is targeting a total area of about 20 sq degrees.  (This figure will be refined subject to calculations of observing time versus sensitivity once the MeerKAT technical specifications are known.)  The intent is to combine three bands; L-band and S-band from MeerkAT, and 500-900 MHz with uGMRT.    With a 30 km maximum baseline, the GMRT provides a good match in resolution with MeerKAT at S-band.   Nominal sensitivity targets are about 0.5μJy at S-band and about 1 μJy at the lower frequencies.  

Exposure times and Area coverage

Ideally we would like to cover the key ancillary data for deep fields. For ELAIS-S1, XMMLSS and ECDFS. 

The MIGHTEE-DATA team has analysed the sensivity versus time and area for the updated MeerKAT specs including the effects of confusion.  Because of confusion a point of diminishing returns in terms of reduced map rms versus time for continuum imaging is reached after about 10 hours per field.   Their report is here. For an area of 20 sq degrees, an rms of about 2 microJy is achieved in about 64% of the 1500 hour allocation, and little improvement is gained by further integration.  We therefore propose to spend about 60% of the time on L-band and 40% on S-band.  This will allow us to cover about 9 sq degrees to similar sensitivity in L band.

Strawman distribution of area coverage among the four fields is shown in the figure below.