Preface

Single copies of the bulletins are available at no cost and may be ordered by sending a 9 x 12 inch self addressed stamped envelope (SASE) with sufficient postage (12 oz. or 340 g.). Use stamps only; cash or checks cannot be accepted. Requests within the U. S. may use the Postal Service's Priority Mail for $3.20. Please print the eclipse date (year & month) or the NASA publication number in the lower left corner of the return SASE. Requests from outside the U. S. and Canada may send ten international postal coupons to cover postage. Exceptions to the postage requirements will be made to professional researchers and scientists, or for international requests where political or economic restraints prevent the transfer of funds to other countries. All requests should be accompanied by a copy of the request form on the last page.

The 2001 bulletin uses two mapping data bases for the path figures: World Vector Shoreline (WVS) and World Data Bank II (WDBII). The WDBII outline files were digitized from navigational charts to a scale of approximately 1:3,000,000, and represent the "state of the art" in the 1970s. The WVS data are given at several resolutions, including 1:1,000,000, 1:250,000 and 1:100,000. For maximum efficiency and speed, these data have been compressed and reformatted into direct access files by Jan C. Depner (U. S. Naval Oceanographic Office) and James A. Hammak (NORDA). WDBII and WVS are available through the Global Relief Data CD-ROM from the National Geophysical Data Center. These vector data have made it possible to generate eclipse path figures at resolutions greater than 1:10,000,000. The more detailed path figures include curves of constant duration of totality within the umbral path. This permits the user to quickly estimate the duration of totality at various locations shown in the figures.

High detail maps of the eclipse track appear in the last section of this publication. The maps are constructed from the Digital Chart of the World (DCW), a digital database of the world developed by the U.S. Defense Mapping Agency (DMA). The primary sources of information for the geographic database are the Operational Navigation Charts (ONC) and the Jet Navigation Charts (JNC). The original map scale of these maps was 1:1,000,000. We have expanded the scale to 1:2,500,000 in order to show major roads, cities and villages, coarse topography, lakes and rivers, suitable for eclipse expedition planning.

The geographic coordinates data base includes over 90,000 cities and locations. This permits the identification of many more cities within the umbral path and their subsequent inclusion in the local circumstances tables. These same coordinates are plotted in the path figures and are labeled when the scale allows. The source of these coordinates is Rand McNally's The New International Atlas. A subset of these coordinates is available in a digital form which we've augmented with population data.

The bulletins have undergone a great deal of change since their inception in 1993. The expansion of the mapping and geographic coordinates data bases have significantly improved the coverage and level of detail demanded by eclipse planning. Some of these changes are the direct result of suggestions from our readers. We strongly encourage you to share your comments, suggestions and criticisms on how to improve the content and layout in subsequent editions. Although every effort is made to ensure that the bulletins are as accurate as possible, an error occasionally slips by. We would appreciate your assistance in reporting all errors, regardless of their magnitude.

We thank Dr. B. Ralph Chou for a comprehensive discussion on solar eclipse eye safety. Dr. Chou is Professor of Optometry at the University of Waterloo and he has over twenty-five years of eclipse observing experience. As a leading authority on the subject, Dr. Chou's contribution should help dispel much of the fear and misinformation about safe eclipse viewing.

Dr. Joe Gurman (GSFC/Solar Physics Branch) has made this and previous eclipse bulletins available over the Internet. They can be read or downloaded via the World-Wide Web from Goddard's Solar Data Analysis Center eclipse information page.

During 1996, Espenak developed a < ahref= "http://sunearth.gsfc.nasa.gov/eclipse/eclipse.html">new Web site which provides general information on both solar and lunar eclipses occurring during the next two decades. Hints on eclipse photography and eye safety may be found there as well as links to other eclipse related web site.

In addition to the general information web site above, a Web site devoted to the 2001 total solar eclipse has been set up. It includes supplemental predictions, figures and maps which could not be included in the present publication.

Since the eclipse bulletins are of a limited and finite size, they cannot include everything needed by every scientific investigation. Some investigators may require exact contact times which include lunar limb effects or for a specific observing site not listed in the bulletin. Other investigations may need customized predictions for an aerial rendezvous or from the path limits for grazing eclipse experiments. We would like to assist such investigations by offering to calculate additional predictions for any professionals or large groups of amateurs. Please contact Espenak with complete details and eclipse prediction requirements.

We would like to acknowledge the valued contributions of a number of individuals who were essential to the success of this publication. The format and content of the NASA eclipse bulletins has drawn heavily upon over 40 years of eclipse Circulars published by the U. S. Naval Observatory. We owe a debt of gratitude to past and present staff of that institution who have performed this service for so many years. The many publications and algorithms of Dr. Jean Meeus have served to inspire a life-long interest in eclipse prediction. We thank Francis Reddy, who helped develop the original data base of geographic coordinates and to Rique Pottenger (Astro Communications Service) for his assistance in expanding the data base to over 90,000 cities. Internet availability of the eclipse bulletins is due to the efforts of Dr. Joseph B. Gurman. The support of Environment Canada is acknowledged in the acquisition of the weather data.

Permission is freely granted to reproduce any portion of this publication, including data, figures, maps, tables and text. All uses and/or publication of this material should be accompanied by an appropriate acknowledgment (e.g. - "Reprinted from Total Solar Eclipse of 2001 June 21, Espenak and Anderson, 1999"). We would appreciate receiving a copy of any publications where this material appears.

The names and spellings of countries, cities and other geopolitical regions are not authoritative, nor do they imply any official recognition in status. Corrections to names, geographic coordinates and elevations are actively solicited in order to update the data base for future eclipses. All calculations, diagrams and opinions are those of the authors and they assume full responsibility for their accuracy.

Previous bulletins were published as NASA Reference Publications (RP's). That series has now been replaced by the NASA Technical Publication (TP) series.

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