(delay) Doppler Map (DM)
Doppler map
“A map made from modern weather radar that uses the Doppler technique to examine the motion of precipitation.” (GIS Dictionary 2025)
Delay Doppler map
"A delay Doppler map is a two-dimensional representation of GNSS-R measurements, obtained by cross-correlating the reflected GNSS signal with a local replica over grids of time delay and Doppler frequency. The resulting signal power distribution encodes surface characteristics, such as roughness and dielectric properties.” (Huang et al. 2021)
GIS Dictionary. 2025. “Doppler Radar Map Definition .” Accessed August 26. https://support.esri.com/en-us/gis-dictionary/doppler-radar-map.
Huang, Feixiong, James L. Garrison, S. Mark Leidner, Bachir Annane, Ross N. Hoffman, Giuseppe Grieco, and Ad Stoffelen. 2021. “A Forward Model for Data Assimilation of GNSS Ocean Reflectometry Delay-Doppler Maps.” IEEE Transactions on Geoscience and Remote Sensing 59 (3). Institute of Electrical and Electronics Engineers Inc.: 2643–56. doi:10.1109/TGRS.2020.3002801.