This article lists computer monitor, television, digital film, and other graphics display resolutions that are in common use.
The increased resolution over D1 comes as a result of a longer horizontal scan.
The extra pixels are used to form the increased area to the sides of the D1 image.
The pixel density of 960H is identical to standard D1 resolution so it does not give any improvement in image quality, merely a wider aspect ratio.
Alternative analog video transport technologies carrying higher resolutions than 960H include HD-TVI, HDCVI, and AHD.