Guide to Best Practices for Georeferencing Guide to Best Practices for Georeferencing BioGeomancer Consortium August 2006 Published by: Global Biodiversity Information Facility, Copenhagen http://www.gbif.org Copyright © 2006 The Regents of the University of California. All rights reserved. The information in this book represents the professional opinion of the authors, and does not necessarily represent the views of the publisher or of the Regents of the University of California. While the authors and the publisher have attempted to make this book as accurate and as thorough as possible, the information contained herein is provided on an "As Is" basis, and without any warranties with respect to its accuracy or completeness. The authors, the publisher and the Regents of the University of California shall have no liability to any person or entity for any loss or damage caused by using the information provided in this book. Guide to Best Practices for Georeferencing Includes Index ISBN: 87-92020-00-3 Recommended Citation: Chapman, A.D. and J. Wieczorek (eds). 2006. Guide to Best Practices for Georeferencing. Copenhagen: Global Biodiversity Information Facility. Edited by: Arthur D. Chapman and John Wieczorek Contributors: J.Wieczorek, R.Guralnick, A.Chapman, C.Frazier, N.Rios, R.Beaman, Q.Guo. Contents CONTENTS ..............................................................................................................................................I GLOSSARY ...........................................................................................................................................III INTRODUCTION ................................................................................................................................... 1 1. DEFINITION ........................................................................................................................................ 1 2. PRINCIPLES OF BEST PRACTICE .......................................................................................................... 1 BACKGROUND ...................................................................................................................................... 3 BIOGEOMANCER CLASSIC..................................................................................................................... 3 MANIS .................................................................................................................................................. 3 MAPSTEDI ............................................................................................................................................ 3 INRAM ................................................................................................................................................. 3 GEOLOCATE ......................................................................................................................................... 4 ERIN ..................................................................................................................................................... 4 KEY DOCUMENTS AND LINKS ................................................................................................................ 4 COLLECTING AND RECORDING DATA IN THE FIELD............................................................. 7 1. THE IMPORTANCE OF GOOD LOCALITY DATA RECORDING................................................................ 7 2. RECORDING LOCALITIES .................................................................................................................... 7 3. RECORDING COORDINATES ................................................................................................................ 8 4. USING A GPS ..................................................................................................................................... 8 5. RECORDING DATUM......................................................................................................................... 10 6. RECORDING ELEVATION .................................................................................................................. 10 7. RECORDING HEADINGS .................................................................................................................... 10 8. RECORDING EXTENT ........................................................................................................................ 11 9. RECORDING YEAR OF COLLECTION.................................................................................................. 11 10. DOCUMENTATION .......................................................................................................................... 11 11. RECORDING DATA FOR SMALL LABELS ......................................................................................... 12 12. NEW TECHNOLOGIES ..................................................................................................................... 12 BEGINNING THE GEOREFERENCING PROCESS ...................................................................... 13 1. INTRODUCTION ................................................................................................................................13 2. THE RESOURCES NEEDED ................................................................................................................ 14 3. FIELDS TO INCLUDE IN YOUR DATABASE ......................................................................................... 14 a. Determine what fields you need ................................................................................................. 14 b. Locality fields ............................................................................................................................. 14 c. Georeferencing fields ................................................................................................................. 15 d. Ecological data .......................................................................................................................... 16 e. Applying constraints................................................................................................................... 16 4. USER INTERFACES............................................................................................................................ 17 5. USING STANDARDS AND GUIDELINES .............................................................................................. 17 6. CHOOSING A METHODOLOGY .......................................................................................................... 18 a. Sorting records for batch georeferencing .................................................................................. 18 b. Using previously georeferenced records.................................................................................... 19 c. Using BioGeomancer ................................................................................................................. 19 7. DATA ENTRY OPERATORS................................................................................................................ 20 GEOREFERENCING LEGACY DATA............................................................................................. 21 1. CLASSIFYING THE LOCALITY DESCRIPTION ..................................................................................... 21 2. FINDING THE LATITUDE AND LONGITUDE ........................................................................................ 22 3. USING OFFSETS................................................................................................................................22 4. FINDING THE EXTENT....................................................................................................................... 22 5. CALCULATING UNCERTAINTIES ....................................................................................................... 23 a. Calculating uncertainties due to an unknown datum ................................................................. 23 Best Practices for Georeferencing Aug. 2006 i b. Calculating uncertainty from distance ....................................................................................... 24 c. Calculating uncertainties from extents of localities ................................................................... 25 d. Calculating uncertainty from direction ...................................................................................... 26 e. Calculating uncertainty from coordinate precision.................................................................... 27 f. Calculating uncertainty by reading off a map............................................................................. 28 g. Calculating combined uncertainties........................................................................................... 30 h. Using the MaNIS Georeferencing Calculator ............................................................................ 30 6. DETERMINING SPATIAL FIT.............................................................................................................. 31 MAINTAINING DATA QUALITY ..................................................................................................... 33 1. FEEDBACK TO COLLECTORS............................................................................................................. 33 2. ACCEPTING FEEDBACK FROM USERS ..............................................................................................