GIS Tips and Tricks Jennifer Harrison President, Inner Corridor Technologies, Inc. ESRI Certified Training Partner (CTP) 1-1 Let s talk about chocolate 1-2 Revised 04/11 1
Tips and Tricks for working with data that you pull off the web. Overview Get to know the data before you consume it! Why won t my data line up? (Datum Transformations) A little aside to dimensions. Is this the same dataset I found on that other website? (Feature compare) Packaging your maps 1-3 Get to know data before you consume it! 1-4 Revised 04/11 2
Check the wrapper! When was this data created? Who created it? At what scale was the data originally created? What are the units used for the attributes? Who is allowed to use the data? Is it free? How do I credit it? Etc. 1-5 When was this image captured? For the ArcGIS online imagery, identify a pixel. 1-6 Revised 04/11 3
What is NAIP? NAIP The National Agriculture Imagery Program (NAIP) acquires aerial imagery during the agricultural growing seasons in the continental U.S. leaf-on" imagery 3-year collection cycle 1-7 And check the description. Where did this image come from? 1-8 Revised 04/11 4
And of course, check the metadata. Where did this data come from? Vendors 1-9 World Imagery or BingTM Maps Aerial? Which imagery should I use? Use the Imagery Comparison Application 1-10 Revised 04/11 5
Or use the content viewer 1-11 Be sure to also check the use constraints! Is Bing Maps content free to ArcGIS users? Permissions! Bing Maps is free for internal use. Users who have a commercial application can purchase a Bing Maps annual subscription. ArcGIS Server 10 users get free internal use of Bing Maps with a cap. The size of the cap depends on the license, but for many users the cap is two million transactions per 4 cores per year. Users who have an external application must purchase a Bing Maps annual subscription. 1-12 Revised 04/11 6
Can I print maps that include ArcGIS Online content? Permissions! Yes, you can print maps that include ArcGIS Online content. If you are using a printed map in a report where the ArcGIS Online content comprises less than ten percent of the content, you do not need permission from Esri first. Full, complete, stand-alone maps created from Esri content and/or Bing Maps content cannot be resold, sublicensed, or otherwise transferred without prior, written permission of Esri. Is including a screen capture or printed map in a report considered noncommercial use? Yes. Including a screen capture or printed map in a report that references ArcGIS Online services or Bing Maps is considered noncommercial use as long as the maps using this content represent less than 10% of the document. Your customers can use this content for internal use only and cannot resell this content. 1-13 Be sure that you know the datum and projection used for the data! Get to know your data! 1-14 Revised 04/11 7
Why won t my data line up? (Datum Transformations) 1-15 SHIFT happens, dude. Datum Transformations 1-16 Revised 04/11 8
Datum Shifts in North America NAD27 NAD83 WGS84 I got this man. ArcGIS handles projections. 1-17 Datum Shifts Yes, shift happens. But not always. Why? And When? And how can I prevent it? 1-18 Revised 04/11 9
Datum Transformation Methods Example transformations for the continental US Data Frame s Datum Layer s Datum NAD27 NAD27 ---------------------- NAD83 WGS84 Transformations works both ways! Transformation NAD_1927_TO_NAD_1983_ NADCON Depends on what part of the US! NAD83 NAD27 NAD_1927_TO_NAD_1983_ NADCON NAD83 ---------------------- WGS84 NAD_1983_To_WGS_1984_5 WGS84 NAD27 Depends on what part of the US! NAD83 NAD_1983_To_WGS_1984_5 WGS84 ---------------------- 1-19 Datum Transformation Methods Example transformations for the continental US NAD_1927_To_WGS_1984_4 (USA - conus) NAD_1927_To_WGS_1984_5 (USA - conus east of Mississippi River) NAD_1927_To_WGS_1984_6 (USA - conus west of Mississippi River) NAD_1927_To_WGS_1984_7 (USA - Alaska mainland) NAD_1927_To_WGS_1984_80 (USA - GoM - east of 87.25 W) NAD_1927_To_WGS_1984_81 (USA - GoM - 95 W to 87.25 W) NAD_1927_To_WGS_1984_82 (USA - GoM - west of 95 W) NAD_1927_To_WGS_1984_84 (USA - GoM) NAD_1927_To_WGS_1984_85 (USA - Alaska including EEZ) -many, many more. 1-20 Revised 04/11 10
ArcGIS Online Images In what datum is the ArcGIS Online world imagery? WGS84 1-21 Does it matter? How much of a difference can it make? In this part of north Louisiana: 75 ft (NAD27/WGS84) 7 ft (NAD83/WGS84) 1-22 Revised 04/11 11
Further off? 146 ft in the Gulf of Mexico(NAD27/WGS84) 1-23 WHEN? Any time EXCEPT when you are using only NAD27 and NAD83 data in North America. HOW CAN I PREVENT IT? Choose the proper datum transformation method! SHIFT happens, dude. Don t get busted! Datum Shifts in the US 1-24 Revised 04/11 12
A little aside into dimensions. 1-25 A little aside. Ever tried to label distances on a map and create those nice little arrows? 1-26 Revised 04/11 13
Dimensions Dimensions can be created in any units, regardless of the map units and even if the length values are not stored in the attribute tables. 1-27 Dimensions Dimensions have to be stored in a geodatbase feature class (no shape files) 1-28 Revised 04/11 14
Dimensions have special style properties. Dimensions 1-29 And special attributes Dimensions 1-30 Revised 04/11 15
There are a special set of construction tools for dimensions. Dimensions Aligned dimensions measure lengths along a feature, Linear dimensions measure the length along the line that you draw. 1-31 Created in an edit session. Dimensions Requires ArcINFO or ArcEditor. Check the online help for more info. on creating dimensions! 1-32 Revised 04/11 16
Tips and Tricks Tips and Tricks for working with data that you pull off the web. Get to know the data before you consume it! Why won t my data line up? (Datum Transformations) A little aside to dimensions. Is this the same dataset I found on that other website? (Feature compare) Packaging your maps 1-33 Is this the same dataset I found on that other website? 1-34 Revised 04/11 17
Feature Compare Tools for comparing datasets Compares two feature classes and reports the differences Find Identical Searches through a feature 1-35 Feature Compare 1-36 Revised 04/11 18
Feature Compare Output Output is a comma-delimited text file that can be viewed as a table. 1-37 How can I easily package my map and take it out in the field? 1-38 Revised 04/11 19
What datasets are used? Want to know which datasets are used by a map? 1-39 Hotlinks. Embedded documents What might be missing?? 1-40 Revised 04/11 20
So how do you move the map and the data around? Package Map Consolidate Map Package Your Map! 1-41 Combine all data and drawing instructions in one special file, a map package. Package Your Map! Metadata (layer descriptions) go with the data. Hyperlink instructions go, but not the data. 1-42 Revised 04/11 21
Make sure to give your map a description first! Package Your Map! 1-43 Combine all data and drawing instructions in one directory. Consolidate Your Map! You still have access to the individual files! Metadata (layer descriptions) go with the data. Hyperlink instructions go, but not the data. 1-44 Revised 04/11 22
Decide whether to convert shape files and images to geodatabase features and rasters. Consolidate Map 1-45 Package vs. Consolidate! Consolidate gives you access to the component datasets. 1-46 Revised 04/11 23
Add metadata! What should you do before packing? 1-47 In summary.. Data is like a chocolate. Get to know your data before you consume it! Projection/datum. Permissions. Time frame. Wrap your data well before you share it! Thanks for joining us! 1-48 Revised 04/11 24