Walter Scott, Jr. College of Engineering

Graduate Exam Abstract

Victoria Hadel
M.S. Final
Jul 17, 2014, 2:00 PM
Development of Internally-Calibrated, Direct-Detection Millimeter-Wave Radiometers to Improve Remote Sensing of Wet-Tropospheric Path Delay
Abstract: Current satellite ocean altimeters include nadir-
viewing, co-located 18-34 GHz microwave
radiometers to measure wet-tropospheric path
delay. Due to the large antenna footprint sizes
at these frequencies, the accuracy of wet path
retrievals is substantially degraded within 40 km
of coastlines, and retrievals are not provided
over land. A viable approach to improve their
capability is to add wide-band millimeter-wave
window channels in the 90-180 GHz band, thereby
achieving finer spatial resolution for a fixed
antenna size. In this context, the upcoming
Surface Water and Ocean Topography (SWOT) mission
is in formulation and planned for launch in late
2020 to improve satellite altimetry to meet the
science needs of both oceanography and hydrology
and to transition satellite altimetry from the
open ocean into the coastal zone and over inland
water. To address wet-path delay in these
regions, the addition of 90-180 GHz millimeter-
wave window-channel radiometers to current Jason-
class 18-34 GHz radiometers, such as is under
consideration for the Jason Continuity of Service
mission, is expected to improve retrievals of wet-
tropospheric delay in coastal areas and to enhance
the potential for over-land retrievals.
To this end, an internally-calibrated, wide-band,
cross-track scanning airborne microwave and
millimeter-wave radiometer is being developed in
collaboration between Colorado State University
(CSU) and Caltech/NASA’s Jet Propulsion Laboratory
(JPL). This airborne radiometer includes microwave
channels at 18.7, 23.8, and 34.0 GHz at both H and
V polarizations; millimeter-wave window channels
at 90, 130, 168 GHz; and temperature and water
vapor sounding channels adjacent to the 118 and
183 GHz absorption lines, respectively. Since this
instrument is a space flight prototype,
substantial effort has been devoted to minimizing
the mass, size and power consumption of the
radiometer’s front end.
Adviser: Prof. Steven C. Reising
Co-Adviser: N/A
Non-ECE Member: Sue Van Den Heever
Member 3: Pekka Kangaslahti
Addional Members: Branislav Notaros
Program of Study: