The beam filling error in the Nimbus 5 electronically scanning microwave radiometer observations of Global Atlantic Tropical Experiment rainfall Academic Article uri icon

abstract

  • A comparison of rain rates retrieved from the Nimbus 5 electronically scanning microwave radiometer (ESMR 5) brightness temperatures and observed from shipboard radars during GATE phase I shows that the beam filling error is the major source of discrepancy between the two. When averaged over a large scene (the GATE radar array, 400 km in diameter), the beam filling error is quite stable, being 50% of the observed rain rate. This suggests the simple procedure of multiplying retrieved rain rates by 2 (correction factor). A statistical model of the beam filling error is developed by envisioning an idealized instrument field-of-view that encompasses an entire gamma distribution of rain rates. A modeled correction factor near 2 is found for rain rate and temperature characteristics consistent with GATE conditions. -from Authors

author list (cited authors)

  • Short, D. A., & North, G. R.

citation count

  • 59

publication date

  • January 1990