Articles | Volume 7, issue 12
Research article
20 Dec 2014
Research article |  | 20 Dec 2014

HAMP – the microwave package on the High Altitude and LOng range research aircraft (HALO)

M. Mech, E. Orlandi, S. Crewell, F. Ament, L. Hirsch, M. Hagen, G. Peters, and B. Stevens

Abstract. An advanced package of microwave remote sensing instrumentation has been developed for the operation on the new German High Altitude LOng range research aircraft (HALO). The HALO Microwave Package, HAMP, consists of two nadir-looking instruments: a cloud radar at 36 GHz and a suite of passive microwave radiometers with 26 frequencies in different bands between 22.24 and 183.31 ± 12.5 GHz. We present a description of HAMP's instrumentation together with an illustration of its potential. To demonstrate this potential, synthetic measurements for the implemented passive microwave frequencies and the cloud radar based on cloud-resolving and radiative transfer model calculations were performed. These illustrate the advantage of HAMP's chosen frequency coverage, which allows for improved detection of hydrometeors both via the emission and scattering of radiation. Regression algorithms compare HAMP retrieval with standard satellite instruments from polar orbiters and show its advantages particularly for the lower atmosphere with a root-mean-square error reduced by 5 and 15% for temperature and humidity, respectively. HAMP's main advantage is the high spatial resolution of about 1 km, which is illustrated by first measurements from test flights. Together these qualities make it an exciting tool for gaining a better understanding of cloud processes, testing retrieval algorithms, defining future satellite instrument specifications, and validating platforms after they have been placed in orbit.

Short summary
Here the High Altitude and LOng range research aircraft Microwave Package (HAMP) is introduced. The package consists of three passive radiometer modules with 26 channels between 22 and 183 GHz and a 36 GHz Doppler cloud radar. The manuscript describes the instrument specifications, the installation in the aircraft, and the operation. Furthermore, results from simulation and retrieval studies, as well as measurements from a first test campaign, are shown.