Holes (Hardcover) (ISBN-13: 9781025096049)

Ionospheric scintillation of GPS signals threatens navigation and military operations by degrading performance or making GPS unavailable. Scintillation is particularly active, although not limited to, a belt encircling the earth within 20 of the geomagnetic equator. This belt also hosted roughly half of the completed U.S. military operations in the last decade. We examined scintillation data from Ascension Island, U.K. and Ancon, Peru, in the Atlantic and Americas longitudinal sector at as well as data from Parepare, Indonesia and Marak Parak, Malaysia in the Pacific longitudinal sector. From these data, we calculate percent probability of occurrence of scintillation at various intensities described by the S4 index. Additionally, we determine Dilution of Precision at one minute resolution. Diurnal, seasonal and solar cycle characteristics are examined. Latitudinal and longitudinal comparisons are made. Our findings are consistent with previous research. Unlike previous research, however, we attempt to replace, or impute, missing S4 values in order to better capture the extent of scintillation. In doing so, we study data gaps, or holes, and characterize them.

This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.

This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.

As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.