GTDR-derived GIS Products for Venus: Smoothed Elevation, Slope Angle, and Slope Aspect Maps

# Created by Gerard Gallardo i Peres# ---------------------------------------------------------#### ----------------------------------------------------------# Author: Gerard Gallardo i Peres / Imperial College London, isardSAT## Contributors / Reviewers: Dr. Philippa J. Mason / Prof. Richard C. Ghail / Dr. Anne Grete Straume-Lindner / Dr. Colin F. Wilson / Dr. Alba Granados / Dr. Mònica Roca #################################################################################### ####### ####### #################################### ########## ############### ##################################### ########## ############### ##################################### ########## ############### ################################# ####### ####### ################################################################################################# This dataset contains products derived from the Magellan Global Topographic Data Record (GTDR) volume 3 (Rappaport et al., 1999) in Mercator Projection (66.5 N to 66.5 S coverage). The dataset is intended to aid any semi-global study on Venus that could benefit from a global map of slopes and filtered/smoothed topography at an approximate spatial scale of 20 km (topography) and 25 km (slopes). The map files are all in GeoTIFF format and are projected using the 1985 COSPAR Venus reference ellipsoid (https://epsg.io/104901). They are embedded with the complete georeferencing metadata (coordinate reference system, geotransform, and spatial extent) to facilitate their direct use in GIS software. gtdr_merc_v3 is the reference topography product, with gtdr_merc_v3_processed is a post-processed, filtered and smoothed version of the GTDR v3 product. Elevation values correspond to altitude above the reference radius value of the GTDR product, R = 6039999 m. The files gtdr_merc_v3_processed_slope_angle and gtdr_merc_v3_processed_slope_aspect represent the GIS slope field derived from the post-processed topography; slope angle is defined between 0º and 90º while slope aspect is defined from 0 to 360º, clock-wise from North. The manual attached (README) describes in detail the processing chain applied to produce the files as well as their overall characteristics. Comparative examples are attached and can also be found in the manual. Disclaimer: This dataset is for research purposes only. It has not undergone formal peer review and does not represent the official views, plans, or policies of any government agency or space mission.