Changes between Version 6 and Version 9 of Ticket #168


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Timestamp:
01/03/18 22:38:58 (13 months ago)
Author:
mikedixon
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  • Ticket #168 – Description

    v6 v9  
    11== Introduction ==
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    3 Radars 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.
     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. The samples in range are frequently referred to as 'gates'.
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    5 The 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.
     5The raw data is stored in radial (polar) coordinates. The (x,y) location of a gate may be determined using traditional great-circle techniques, since these are line-of-sight instruments and the propagation is assumed to be along a straight line in (x,y). In the vertical (z) dimension, a standard model of atmospheric refractive index is generally assumed for locating the height of the gate.
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    7 The organization and interpretation of radial data of this type is not supported by any of the standard grid mapping types currently supported by CF.
     7The organization and interpretation of radial data of this type is not supported by any of the standard grid mapping types currently accepted by CF.
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    99Therefore, 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.
     
    3131The height_of_projection_origin parameter is analogous to the perspective_point_height in the vertical perspective projection.
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    33 The document is maintained at:
     33The supporting documents are maintained at:
    3434
    3535  https://github.com/NCAR/CfRadial/tree/master/docs