Construction of a Global Map Around Mindanao, Philippines/1
Jose Edgardo L. Aban
Philippine council for Advanced Science and Technology
Research and Development
department of science and technology
dost compound, gen. Santos Ave.,
Bicutan, Tagig, Metro Manila
Tel: (632) 837-7522 Fax: (632) 8373168
E-Mail: egay@sun1.dost.gov.ph
Abstract :
A 1-kilometer resolution Global Map, Philippines was constructed using data from the Digital Chart of the world (DCW), GTOPO3O elevation data, and classified IGBP image format. These data were converted to an image format using GeoSTAR
TM program, that can be read and processed with the ARView
TM software on the desktop computer. Various themes were produced of the area, including road/transportation layer, drainage, urban/built-up areas, elevation, and administrative boundary layer.
Introduction
In order that global issues may be addressed, an improved understanding of the Earth as a system must be established.The construction of a Global Map is aimed at developing a common world map for the next Millllenium. This world should have the following characteristics, to wit 1) it should cover the land area of the whole world; 2) it should include Geographical information directly connected with environment , such as vegetation and land use ; 3) it should have globally consistent accuracy; and 4) it should be in usable digital form.
This study aims to illustrate what can be done with existing data of the Philippines to provide various map information in a format that confirm with that conform with that of the Global Map. The general objective of this Global Mapping Sample production resides on using existing global geographic digital data, of selected sample areas, for checking data availability, accuracy and reliability.
Methodology
Selection of Sample Areas
The sample areas were selected according to available digital data and paper maps corresponding to existing 1:50.000 map sheets, making possible the final checking.
Sources of Digital and Other Data
Elevation data were sourced primarily from the Global 30 Arc Second Elevation Data Set (GTOPO30). The GTOPO30 is a global digital elevation model (DEM), regularly spaced at 30- arc seconds which produces a grid system with approximately 1-Km interval in longitude. Data are provide in what is termed as titles covering, on average, 50 degrees of latitude by 40 degrees of longitude.
GTOPO30 has been divided in 33. Data for the each tile are provided in a set of 8 files with the extension indicating its contents.
.DEM digital elevation model data
.HDR header file for DEM
.DMW world file
.STX statistics file
.PRJ projection information file
.GIF shaded relief image
.SRC source map
.SCH header file for source map
For the scope of this work the .DEM files were used. These .DEM files provided 16-bit signed integer data, in a simple binary raster, processed and converted with the software GoeSTAR
TM to a readable ARC/INFO
TM format necessary to match with the sample areas vector data.
