Analysis on the Effect of Map Projection System for Area Calculation

Map projection is required for modeling the earth from sphere into flat form. Out of so many types of projection systems, Universal Transverse Mercator (UTM) is the most common map projection system used in Indonesia. The concept of Mercator projection system is to maintain the angle but cause distortion on the area and distance. This will become problem if it is used for calculating an area that require minimum distortion, especially on a large scale. This study aims to find out the effect of the projection system for any scale to the area, and find out the best projections system in Indonesia. In this paper, the area was calculated using 72 projection systems with various scale using MATLAB software. The reference area that considered true was the polygon area of an ellipsoid so the difference between area of ellipsoid and projection can be known. The projection systems that give minimum distortion are the most optimum result. Based on the study, the most suitable projection system for calculating the area with minimal distortion is Collignon for 1: 250,000 scale and 1: 50,000, Eckert II projection system for 1: 25,000 scale and Equal-area Conic Albers Standard projection system for scale 1: 5,000

A Map of the Universe

We have produced a new conformal map of the universe illustrating recent discoveries, ranging from Kuiper belt objects in the Solar system, to the galaxies and quasars from the Sloan Digital Sky Survey. This map projection, based on the logarithm map of the complex plane, preserves shapes locally, and yet is able to display the entire range of astronomical scales from the Earth's neighborhood to the cosmic microwave background. The conformal nature of the projection, preserving shapes locally, may be of particular use for analyzing large scale structure. Prominent in the map is a Sloan Great Wall of galaxies 1.37 billion light years long, 80% longer than the Great Wall discovered by Geller and Huchra and therefore the largest observed structure in the universe.Comment: Figure 8, and additional material accessible on the web at: http://www.astro.princeton.edu/~mjuric/universe

Genus Topology of the Cosmic Microwave Background from the WMAP 3-Year Data

We have independently measured the genus topology of the temperature fluctuations in the cosmic microwave background seen in the Wilkinson Microwave Anisotropy Probe (WMAP) 3-year data. A genus analysis of the WMAP data indicates consistency with Gaussian random-phase initial conditions, as predicted by standard inflation. We set 95% confidence limits on non-linearities of -101 < f_{nl} < 107. We also find that the observed low l (l <= 8) modes show a slight anti-correlation with the Galactic foreground, but not exceeding 95% confidence, and that the topology defined by these modes is consistent with that of a Gaussian random-phase distribution (within 95% confidence).Comment: MNRAS LaTeX style (mn2e.cls), EPS and JPEG figure

Representations of celestial coordinates in FITS

In Paper I, Greisen & Calabretta (2002) describe a generalized method for assigning physical coordinates to FITS image pixels. This paper implements this method for all spherical map projections likely to be of interest in astronomy. The new methods encompass existing informal FITS spherical coordinate conventions and translations from them are described. Detailed examples of header interpretation and construction are given.Comment: Consequent to Paper I: "Representations of world coordinates in FITS". 45 pages, 38 figures, 13 tables, aa macros v5.2 (2002/Jun). Both papers submitted to Astronomy & Astrophysics (2002/07/19). Replaced to try to get figure and table placement right (no textual changes