Algeria, 1846 (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: Carte de l'Algérie : divisée par tribus, par mm. E. Carette et Augte. Warnier, membres de la Commission Scientifique de l'Algérie. It was published by Institut géographique national in 1846. Scale 1:1,000,000. Covers northern part of Algeria and portions of Tunisia and Morocco. Map in French. The image inside the map neatline is georeferenced to the surface of the earth and fit to the Europe Lambert Conformal Conic coordinate system. All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as drainage, cities and other human settlements, roads adn routes, administrative and territorial boundaries, shoreline features, and more. Includes notes on native populations and inset of Mediterranean Sea region. This layer is part of a selection of digitally scanned and georeferenced historic maps from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of originators, ground condition dates, scales, and map purposes.

Historic paper maps can provide an excellent view of the changes that have occurred in the cultural and physical landscape. The wide range of information provided on these maps make them useful in the study of historic geography, and urban and rural land use change. As this map has been georeferenced, it can be used in a GIS as a source or background layer in conjunction with other GIS data.

source map publication date.

map.

None.

The georeferenced raster is a faithfully reproduced digital image of the original source map. Some differences may be detected between the source graphic used and the raster image due to the RGB values assigned that particular color. The intent is to recreate those colors as near as possible. Data completeness for raster digital image files reflect content of the source graphic. Features may have been eliminated or generalized on the source graphic due to scale and legibility constraints The horizontal positional accuracy of a raster image is approximately the same as the accuracy of the published source map. The lack of a greater accuracy is largely the result of the inaccuracies with the original measurements and possible distortions in the original paper map document. For instance, this map contains grid-like seams that are the result of being formerly folded as a booklet. There may also be errors introduced during the digitizing and georeferencing process. In most cases, however, errors in the raster image are small compared with sources of error in the original map graphic. The RMS error for this map is 8303.17205 meters. This value describes how consistent the transformation is between the different control points (links). The RMS error is only an assessment of the accuracy of the transformation.

ESRI ArcGIS 9.3.

Not applicable.