Search NASA⌕ Search

Engineering topics

Ramos, Isaac

Publications and source records attributed to Ramos, Isaac.

Technology Maturation for Cloud Ice Radiometers

Global measurements of ice in clouds, both the amount and particle size distribution, are critically needed to reduce uncertainties in global climate models. The retrieval of this information is best achieved with a range of receiver channels across the submillimeter wave range. Advancement of low noise Indium Phosphide (InP) MMIC amplifier technology to 25-nm gate length enabled us to develop miniature submillimeter-wave receivers for a CubeSat scale instrument that achieves 6 km spatial resolution. We developed the 25-nm InP MMICs and radiometer receivers for 240, 310, 380, 670 GHz. The 25-nm InP MMIC technology was thermal vacuum tested to reduce risk for future space mission.

Duffy, Maxwell↗

Using Intelligent Targeting to increase the science return of a Smart Ice Storm Hunting Radar

Smart Ice Cloud Sensing (SMICES) is a small-sat concept in which a radar intelligently targets ice storms based on information collected by a lookahead radiometer. Often space observations are performed by continuously collecting data from an instrument aimed at nadir (e.g. directly below the space platform). However, if the platform has the ability to assess science utility of features being overflown, an intelligent measurement scheme can improve science return. This can be achieved by controlling the on/off state of the instrument if it is not able to continuously operate (e.g. due to energy or thermal constraints), and by allowing the instrument to view off nadir if it has pointing capabilities.In the case of SMICES, power constraints and the rarity of storms means that with blind nadir targeting SMICES would collect a limited amount of ice storm radar data. The algorithms proposed acquire measurements to maximize acquired high interest storms while concurrently collecting a background sampling of all features. We use a cloud classification system to identify five different cloud types. Six algorithms ranging from “blind” to more selective are described and results from evaluation on a dataset of 13 ground swaths covering 72,399,600 km2 of data are presented. This data is from high quality science simulations that contain all five cloud types and multiple storms. When utilizing the radiometer’s lookahead and the full range of the radar the results show a 23.7x and 1.9x increase over the base algorithm in the most and second most important cloud types respectively.

Cooke, Caitlyn↗

The Advanced Microwave Radiometer – Climate Quality (AMR-C) Instrument for Sentinel-6

The Advanced Microwave Radiometer – Climate Quality (AMR-C) is designed to measure the path delay due to atmospheric water vapor along Sentinel-6 altimeter path over one decade. The AMR-C receiver is based on heritage from previous AMR instruments with the addition of a THz-frequency radiometer, the High Resolution Microwave Radiometer (HRMR), for improved coastal zone accuracy and a Supplemental Calibration System (SCS) to meet level 3 requirements that the path delay error due to the altimeter-derived sea surface height be less at 0.8 cm and the path delay stability be maintained to 0.7 mm averaged over a 1-year time period.

Maiwald, Frank↗