Using Areal-Scale as Opposed to the Linear-Scale for Map Applications

Maps are made to scale. Scale represents the ratio of distance on the map to distance on a projected coordinate system, i.e., Universal Transverse Mercator (UTM). This specification is, however, limited by the fact that different lines produce different scales. This often has disadvantages for users...

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Main Authors: Helali, H., Awange, Joseph, Omidi, E.
Format: Journal Article
Published: Maney 2010
Subjects:
Online Access:http://hdl.handle.net/20.500.11937/29834
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author Helali, H.
Awange, Joseph
Omidi, E.
author_facet Helali, H.
Awange, Joseph
Omidi, E.
author_sort Helali, H.
building Curtin Institutional Repository
collection Online Access
description Maps are made to scale. Scale represents the ratio of distance on the map to distance on a projected coordinate system, i.e., Universal Transverse Mercator (UTM). This specification is, however, limited by the fact that different lines produce different scales. This often has disadvantages for users who may require an optimal scale; one scale representing the entire map. Scale variations clearly show that measurements on maps are deteriorated by biases. It is, therefore, desirable to have a unique scale independent of linear measurements to enhance the accuracy of further data processing. In this contribution, an optimal scale based on the relationship between the areas on a map and a reference ellipsoid is proposed to reduce the distortions of the projected coordinate system.The motivation behind the area approach is the fact that as the number of lines approaches infinity on a map, a surface is built which is accurately represented by an area as opposed to linear features. Using several map projections, this paper demonstrates that linear-scale optimization is achieved through areal-scale. Almost all of the commercial software measure the linear-scale based on one line. The linear scale remains unchanged even if the projection is changed or map view moved. Therefore, this contribution can pave the way for GIS industry to present a better indication of scale and more accurate data processing results.
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spelling curtin-20.500.11937-298342017-09-13T15:53:51Z Using Areal-Scale as Opposed to the Linear-Scale for Map Applications Helali, H. Awange, Joseph Omidi, E. Distortion Map projection Scale Areal-scale GIS Linear-scale Maps are made to scale. Scale represents the ratio of distance on the map to distance on a projected coordinate system, i.e., Universal Transverse Mercator (UTM). This specification is, however, limited by the fact that different lines produce different scales. This often has disadvantages for users who may require an optimal scale; one scale representing the entire map. Scale variations clearly show that measurements on maps are deteriorated by biases. It is, therefore, desirable to have a unique scale independent of linear measurements to enhance the accuracy of further data processing. In this contribution, an optimal scale based on the relationship between the areas on a map and a reference ellipsoid is proposed to reduce the distortions of the projected coordinate system.The motivation behind the area approach is the fact that as the number of lines approaches infinity on a map, a surface is built which is accurately represented by an area as opposed to linear features. Using several map projections, this paper demonstrates that linear-scale optimization is achieved through areal-scale. Almost all of the commercial software measure the linear-scale based on one line. The linear scale remains unchanged even if the projection is changed or map view moved. Therefore, this contribution can pave the way for GIS industry to present a better indication of scale and more accurate data processing results. 2010 Journal Article http://hdl.handle.net/20.500.11937/29834 10.1179/003962610X12747001420627 Maney restricted
spellingShingle Distortion
Map projection
Scale
Areal-scale
GIS
Linear-scale
Helali, H.
Awange, Joseph
Omidi, E.
Using Areal-Scale as Opposed to the Linear-Scale for Map Applications
title Using Areal-Scale as Opposed to the Linear-Scale for Map Applications
title_full Using Areal-Scale as Opposed to the Linear-Scale for Map Applications
title_fullStr Using Areal-Scale as Opposed to the Linear-Scale for Map Applications
title_full_unstemmed Using Areal-Scale as Opposed to the Linear-Scale for Map Applications
title_short Using Areal-Scale as Opposed to the Linear-Scale for Map Applications
title_sort using areal-scale as opposed to the linear-scale for map applications
topic Distortion
Map projection
Scale
Areal-scale
GIS
Linear-scale
url http://hdl.handle.net/20.500.11937/29834