Viking MDIM2.1 Colorized Global Mosaic 232m

This global image map of Mars has a resolution of 256 pixels/degree (scale approximately 231 m/pixel at the equator). The colorized mosaic was completed by NASA AMES which warped the original Viking colorized mosaic and blended over the lastest black/white mosaic. This mosaic, known as Colorized Mars Digital Image Model (MDIM) 2.1. The original MDIM2.1, replaces two earlier mosaics produced by the USGS from the same set of approximately 4600 Viking Orbiter images. The positional accuracy of features in MDIM 2.1 is estimated to be roughly one pixel (200 m), compared to 3 km for MDIM 2.0 released in 2001 and >6 km for MDIM 1.0 released in 1991. In addition to relatively imprecise geodetic control, the previous mosaics were affected by changing definitions of cartographic parameters (such as the definition of zero longitude), resulting in an overall longitude shift of as much as 0.2° between the early MDIMs and other datasets. The new mosaic uses the most recent coordinate system defi

本全球火星图像地图具有256像素/度的分辨率（赤道处的比例约为231米/像素）。该彩色镶嵌图由NASA AMES完成，通过扭曲原始的Viking彩色镶嵌图并与最新的黑白镶嵌图融合而成。此镶嵌图被称为彩色火星数字图像模型（MDIM）2.1版。原始的MDIM2.1取代了美国地质调查局（USGS）从大约4600张Viking轨道器图像中制作的两个早期镶嵌图。MDIM 2.1中特征的位置精度估计大约为一点像素（200米），相较于2001年发布的MDIM 2.0版的三公里精度，以及1991年发布的MDIM 1.0版的大于6公里精度。除了相对不精确的地理控制外，先前的镶嵌图还受到地图学参数定义的变化（例如零经度的定义）的影响，导致早期MDIM与其他数据集之间的经度整体偏移高达0.2°。新的镶嵌图采用了最新的坐标系定义。