Feature Extraction from Pioneer Venus OCPP Data

Scientific visualization provides means to explore data and highlight inter- esting features in the data. In this paper we will discuss the visualization of astrophysical data. Light properties of sunlight scattered by the atmosphere of Venus were measured by the Pioneer Venus Orbiter. One of the objectives of this mission was to determine the properties of the clouds and haze in the atmosphere. Given the amount and complexity of the data, it is important to be able to browse through the data and select maps with interesting features. We built a system that reads the raw data, prepares it and extracts cloud features. The feature extraction is achieved by the following steps: selection, clustering, attribute calculation and iconic mapping. After data exploration a number of consecutive images with coherent moving cloud features, is found. From the center position and the time between two frames, a qualitative measure for the cloud velocities is derived. The obtained velocities are well in correspondence with generally accepted results. Thus we have shown that visualization techniques are powerful tools to browse through the data, recognize cloud features and determine the motions of the features in time.

@InProceedings { RPS97c,
  author       = "Reinders, Freek and Post, Frits H. and Spoelder, H.J.W.",
  title        = "Feature Extraction from Pioneer Venus OCPP Data",
  booktitle    = "Proceedings of the Eighth Eurographics Workshop on Visualization in Scientific Computing",
  month        = "April",
  year         = "1997",
  editor       = "W. Lefer and M. Grave",
  note         = "Boulogne-sur-Mer, France",
  url          = "http://graphics.tudelft.nl/Publications-new/1997/RPS97c"
}