Map of n. eastern Virginia and vicinity of Washington /

Relief shown by hachures. Depths shown by soundings.

[Topographic map of portion of Aberdeen Proving Ground, Maryland, and topographical and architectural examples and exercises] /

Relief shown by contours.

Washington, D.C., 1884 (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: Topographical map of the District of Columbia and a portion of Virginia, compiled under the direction of Major G.J. Lydecker, Corps of Engineers, Engineer Commissioner D.C., by Captain F.V. Greene, Corps of Engineers ; drawn by W.T.O. Bruff. It was published in 1884. Scale [1:15,840]. The image inside the map neatline is georeferenced to the surface of the earth and fit to the Maryland State Plane Coordinate System Meters NAD83 (Fipszone 1900). 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 roads, railroads, drainage, selected public buildings, selected private residences and names of landowners, built-up areas, parks, and more. Relief shown by contours. Depths shown by soundings. Includes source materials note. This layer is part of a selection of digitally scanned and georeferenced historic maps from The Harvard Map Collection as part of the Imaging the Urban Environment project. Maps selected for this project represent major urban areas and cities of the world, at various time periods. These maps typically portray both natural and manmade features at a large scale. The selection represents a range of regions, originators, ground condition dates, scales, and purposes.

Washington, D.C. and vicinity, 1862 (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: Topographical map of the original District of Columbia and environs showing the fortifications around the city of Washington, by E.G. Arnold C.E. It was published by G. Woolworth Colton in 1862. Scale [ca. 1:31,680]. Covers also adjacent portions of Virginia and Maryland. The image inside the map neatline is georeferenced to the surface of the earth and fit to the Maryland State Plane Coordinate System Meters NAD83 (Fipszone 1900). 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 roads, railroads, bridges, canals, drainage, cities and towns, forts, selected public buildings and places of interest, hospitals, schools, Washington, D.C. school districts, selected private residences with names of landowners, and more. Relief is shown by hachures. Includes text and population tables. This layer is part of a selection of digitally scanned and georeferenced historic maps from The Harvard Map Collection as part of the Imaging the Urban Environment project. Maps selected for this project represent major urban areas and cities of the world, at various time periods. These maps typically portray both natural and manmade features at a large scale. The selection represents a range of regions, originators, ground condition dates, scales, and purposes.

Virginia /

Relief shown pictorially.

Virginia /

Relief shown pictorially.

A survey of the northern neck of Virginia, being the lands belonging to the Rt. Honourable Thomas Lord Fairfax Baron Cameron, bounded by & within the Bay of Chesapoyocke and between the rivers Rappahannock and Potowmack: With the courses of the rivers Rappahannock and Potowmack, in Virginia, as surveyed according to order in the years 1736 & 1737.

Scale ca. 1:875,000.

A map of the state of Virginia, reduced from the nine sheet map of the state in conformity to law /

Relief shown by hachures.

[A map of the state of Virginia : constructed in conformity to law from the late surveys authorized by the legislature and other original and authentic documents /

Relief shown by hachures. Depths shown by soundings.

A map of the state of Virginia, constructed in conformity to law from the late surveys authorized by the legislature and other original and authentic documents /

Relief shown by hachures. Depths shown by soundings on Drummond's Lake only.

A map of the state of Virginia, constructed in conformity to law from the late surveys authorized by the legislature and other original and authentic documents /

Relief shown by hachures. Depths shown by soundings.

A map of the state of Virginia : constructed in conformity to law from the late surveys authorized by the legislature and other original and authentic documents /

Relief shown by hachures. Depths shown by soundings.

A map of the state of Virginia, reduced from the nine sheet map of the state in conformity to law /

Relief shown by hachures.

The importance of neighbourhood size in self organising systems

In recent times, the analysis of SOM (self-organising map) performance has concentrated on optimising the gain decay, rather than the size, form and decay of the neighbourhood function. We propose that the size, form and decay of region size plays a much more significant role in the learning, and especially in the development, of topographic feature maps. In this paper, a biologically-derived SOM model is presented. This model is able to select a single winning neuron and to form Gaussian outputs about this winner, without the need for a meta-level decision-making structure to artificially select a winner and fit a Gaussian output to that winner. Using this model, some fundamental characteristics of the relationship between neighbourhood size and SOM output states are demonstrated.

Gakara region, Burundi, 1994, Defense Mapping Agency (DMA) Series Z724, Sheet 4673-I (Raster Image)

This layer is a georeferenced raster image of the United States Defense Mapping Agency (DMA) Series Z724, Burundi, 1:50,000 Topographic Line Map (TLM) Series sheet map entitled: Gakara. Printed in: 1994. Covers portions of Gakara region, Burundi. Sheet: 4673-I. Edition statement: Ed. 1 - DMA. The image inside the map neatline is georeferenced to the surface of the earth and fit to World Geodetic System (1984) coordinates. All map collar information is also available as part of the raster image. Burundi 1:50:000 Series Z724 maps are in English and French (legends also include Rundi). Each source map in the series is printed in color at a scale of 1:50,000. Series source sheets were published in 1994-1995 by the United States Defense Mapping Agency, Hydrographic/Topographic Center. The source map was scanned and georeferenced for Harvard University's Center for Geographic Analysis' AfricaMap project by East View Cartographic. Individual TLM sheets covering Burundi (40 sheets in total) were selected from the TLM worldwide series. DMA Topographic Line Map series maps are typical topographic maps portraying both natural and manmade features. They show and name works of nature, such as mountains, valleys, lakes, rivers, vegetation, etc. They also identify the principal works of humans, such as roads, railroads, boundaries, transmission lines, major buildings, etc. Relief is shown with standard contour intervals of 20 meters, with some sheets having supplemental meter contours, form lines, hachures, shading, and/or spot heights. Depths shown by bathymetric isolines. Please pay close attention to map collar information on projections, spheroid, compilation dates, legend information, and keys to grid numbering and other numbers which appear inside the neatline.