Changes between Version 1 and Version 6 of Ticket #168


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Timestamp:
01/02/18 20:04:08 (18 months ago)
Author:
mikedixon
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  • Ticket #168

    • Property Priority changed from high to medium
  • Ticket #168 – Description

    v1 v6  
    1 Radar and Lidar data in native radial (polar) coordinates is not supported by existing grid mapping types in CF.
     1== Introduction ==
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    3 Therefore we are requesting the addition of a new grid mapping type called 'radar_lidar_radial_scan'.
     3Radars and Lidars sample the atmosphere using a pulse of energy transmitted from an instrument along a line of sight away from the instrument, with a specified beam width (solid angle). The received signal is sampled over time, which allows for the estimation of the distance of the target from the instrument.
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    5 The essential parameters are the latitude, longitude and altitude of the instrument.
     5The raw data is stored in radial (polar) coordinates. The location in space, especially in the vertical, is dependent on the propagation of the energy through the atmosphere. Vertical gradients of the index of refraction lead to complexities in determining the height of the target.
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    7 The full proposal is described in the attached PDF.
     7The organization and interpretation of radial data of this type is not supported by any of the standard grid mapping types currently supported by CF.
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     9Therefore, in order for the CfRadial radar and lidar format to be formally recognized by the CF user community, we are proposing the addition of a grid mapping specifically for radar and lidar data.
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     11== Proposed  grid mapping name ==
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     13We propose the use of the name “radar_lidar_radial_scan”.
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     15== Grid mapping parameters ==
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     17The following example from a '''CfRadial''' file shows the proposed parameters:
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     19{{{
     20grid_mapping:grid_mapping_name = "radar_lidar_radial_scan" ;
     21grid_mapping:longitude_of_projection_origin = -104.545806884766 ;
     22grid_mapping:latitude_of_projection_origin = 39.7866401672363 ;
     23grid_mapping:height_of_projection_origin = 1709. ;
     24}}}
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     27The latitude and longitude are in degrees.
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     29The height is in meters MSL.
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     31The height_of_projection_origin parameter is analogous to the perspective_point_height in the vertical perspective projection.
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    933The document is maintained at:
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    1135  https://github.com/NCAR/CfRadial/tree/master/docs
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