The ability to collect geographically referenced information using your smartphone or tablet is an increasingly popular way to quickly and efficiently collect data. Although there are many different applications that can accomplish this, here we will focus on the Collector App from Esri. This blog posting will focus on the steps necessary to get a web map up and running for use within the Collector app.
To be able to complete this workflow, it is necessary to have an ArcGIS Online Organizational account. At the end of this workflow, the end result will be a web map that can be used within Collector to conduct building damage assessments after a natural disaster (e.g. coastal storm), however you can create your feature class and web map to collect information on anything.
Beginning in ArcMap, we will start by creating a new file geodatabase; you can create this within your Catalog window. Right click on a file folder, and select New > File Geodatabase. Provide your database with a name, for example, I called mine “Matthew_Collector_App” because I will be assessing and mapping building damage caused by Hurricane Matthew.
Once this has been created, we will create some domains for the geodatabase. Attribute domains are rules that determine what values are valid for a specific attribute field. They are handy to use because they allow users to choose attribute values from a pick list when entering attribute information for a new feature. For people using Collector in the field, this eliminates the need to type information for each attribute field and can speed up data collection, while reducing errors.
To create your domains, right click on your new geodatabase in the Catalog window, select Properties and click the Domains tab.
- First, enter a domain name and a brief description for it within the top box.
- My first domain is BuildingType, and its description is “Type of building damaged by the storm”.
- With that domain still selected, set your Domain Properties in the middle box.
- Field Type = Text
- Domain Type = Coded Values
- Split Policy = Default Values
- Merge Policy = Default Values
- In the Coded Values box (bottom box), enter the acceptable values for this domain, this requires a code and a description. See the screen capture below to see my completed BuildingType domain.
- Next, I will follow these same steps to create a domain for the level of damage (LvlDmg); my completed dialog will look like this:
- You can see this domain has 5 different coded values that users can choose from.
Once you have completed all of your domains, you need to create a new point feature class within the geodatabase. Select the WGS 1984 Web Mercator (auxiliary sphere) coordinate system; because this feature class will live and work in ArcGIS Online, you want your coordinate system to match that used in the online mapping environment. Next, add fields for the information you want to collect.
Since I’m using this to assess building damage, not only do I want to collect information on the level of damage and type of building damaged (these are our created domains), I also want information on the building’s name, and it’s unique code, as well as a description of the picture, and information on who collected the point and when. My final fields look like this:
Once you’ve created your fields, you need to associate your domains with the proper attribute field. For this example I need to select BuildingType in the Field Name list. Under the Field Properties section set the following parameters:
- Alias = BuildingType
- Allow NULL values = No (this will ensure this field is always populated with information)
- Domain = BuildingType (you can select this from a pick list)
Repeat this step for the attribute field “LvlDmg”, or whatever other fields you created a domain for.
Note: Collector can also be used to draw a shape; to learn more, visit Esri’s help pages for Collector.
Next, I need to enable attachments so that my users can collect georeferenced photos while conducting their damage assessment. To do this, right click on your point feature class and select Manage > Create Attachments; this will create two new items in your geodatabase – a table and a relationship class.
Now that your feature class is all set up, you can create a symbology for it. When you share your features with ArcGIS Online, this symbology will be applied to all features collected. Drag your features into your ArcMap window and open the dataset properties dialog box. Select the Symbology tab, and then choose to show feature by category.
I decided to choose the LvlDmg as my Value Field; I added all values and then updated each value label to match the value. I then changed the symbology for all values to a house, and modified the color of each to indicate level of damage (e.g. destroyed = red, no damage = green).
Once you’ve applied the symbology, you’re ready to share this as a service with ArcGIS Online. First log into your ArcGIS Online account (File > Sign In…), and then select File > Share As > Service… This opens the Share as Service dialog, using the following steps, share your service with your ArcGIS Online account.
- Select publish a service and click next.
- Choose a connection from the dropdown; you should select “My Hosted Services”.
- Give your service a name – this is what will show up in your content in ArcGIS Online.
- In the Service Editor dialog, set the following:
- On the Capabilities tab select Feature Access.
- On the Feature Access tab check boxes for create, delete, query, sync and update.
- By enabling all of these options, users will be able to create new features, delete features, and sync their collected points with the feature layer in ArcGIS Online.
- On the Item Description tab, fill in summary, tags, description and credits.
- On the Sharing tab, select any groups you’d like to share this service with (you can also share with your organization or the public).
- Click Analyze at the top of the dialog box; this will check your feature class to ensure there are no issues. Generally, as long as there are no issues marked as High Severity, you are all set to share your service.
- Click Publish.
Now we’re ready to open a web browser and log into ArcGIS Online. Once you’ve done this, go to your My Content tab and open your new feature layer. Click on the Settings tab and ensure that under Feature layer (Hosted) Settings that Enable Editing is checked. You can also enable delete protection on this page.
Now, open this feature layer in a new Web Map; zoom to the area in which this feature layer will be used and then Save As a new map. You should give this new Web Map a description so that users know what it is for. Also, from the settings tab you can enable the following options:
Now you’re ready to begin field data collection! Once you download the Collector app onto your mobile phone or tablet, you can log in with your ArcGIS Online credentials, select your web map, and begin collecting points!
This blog posting was developed with the support of a competitive grant (cooperative agreement number P09AC00212; task agreement number P13AC00875) from the National Park Service in partnership with the North Atlantic Coast Cooperative Ecosystems Studies Unit.