High Accuracy Data Collection with Global Mapper Mobile Pro and Emlid
Two main components of GIS are information and position. Information is typically captured through the use of vector feature attributes or data layer metadata, and position is based on the coordinate reference for a piece of data. Both of these critical pieces of GIS data can be captured with Global Mapper Mobile. Available on iOS and Android systems, Global Mapper Mobile assists Global Mapper desktop users by allowing data to be brought into the field for reference, augmentation, and new data collection. Additionally, advanced tools available with the Pro subscription to Global Mapper Mobile and external GNSS devices, like the easy-to-use Emlid Reach RX, help users collect highly accurate data complete with meaningful attributes.
Vector feature attributes hold important contextual information for features collected in Global Mapper Mobile. The collection of attribute information can be customized in the mobile app as new features are created, but a more effective and standardized way for this data collection begins with a Feature Template designed in the Global Mapper desktop Configuration options.
A Feature Template is not a data layer, but merely the structure of one waiting for users to add features. A template name is first given to identify the template, and the vector feature type—point, line, or polygon—is assigned. Next, a default feature symbol, name, and description are optionally added. Finally, the desired attributes for the data to be collected are defined. Three types of attributes are available to be added to a feature template.
A Single Value Attribute is the simplest type, offering a user the option for freeform value entry or applying a default value automatically. When creating a Single Value Attribute, provide a name for the attribute, select the type—string, integer, float, or bool—then optionally add a single default value to always be applied, or leave the value blank, allowing the user to enter the attribute value manually.
An Enumerated Value Attribute appears as a picklist of entered values for the user when a feature is created using the template. This type of attribute allows the template designer to explicitly set the values that can be selected, helping to reduce any user error when entering essential values. To create an Enumerated Value Attribute, set the attribute name and type, and then add accepted values to the list.
Similar in design to the Enumerated Value Attribute, a Style Map Attribute is used to dictate the style used to display the feature on the map visually. Based on the value entered when a feature is added to the template, the style used to show the created feature will be impacted. To create this type of attribute in a Feature Template, set the attribute name and type, and then enter a value option and select an associated feature type style.
To ensure essential information is collected when features are created and added to a Feature Template derived layer, any type of attribute can be set to be required. In practice, this means that the user will have to review or enter a value for the attribute in order for the new feature to be fully created. With a required attribute, there is no method to skip the attribute value entry, so you can be sure the value will not return empty.
The setup for a Feature Template is completed in Global Mapper desktop, and designed templates are stored there in the Configuration settings. These templates can be used to create a new layer by choosing to Create Empty Template Layer from the selected template, but once created a Feature Template will remain in Global Mapper desktop to be used again and again for repeated data collection.
Even without information, a feature cannot be placed on a map without a position. While there are many ways to measure a coordinate position in today’s world, some methods and available equipment make the process easier and allow for higher accuracy in data collection. By default, Global Mapper Mobile will use the available internal location services of the mobile device to collect GPS-informed vector data in the app. However, with the addition of the Pro subscription to Global Mapper Mobile, external GNSS devices and RTK corrections can be used to boost the accuracy of collected data.
In Global Mapper Mobile Pro on any Android device, the Reach RX device from Emlid makes connecting to a GNSS unit easy, allowing users to greatly improve the quality of their collected data. A pocket-sized, and lightweight rover for data collection, the Reach RX provides centimeter-level accuracy data collection and works with Real-Time Kinematic (RTK) correction (via NTRIP).
Emlid Reach RX is a multi-band rover tracking GPS/QZSS, Galileo, Glonass, and Beidou. It’s designed for working with any corrections network (NTRIP) to provide centimeter-accurate positioning. If no network is available, you can create your own using Emlid Reach RS2 or RS2+ as a permanent base and Emlid Caster to send RTK corrections.
Emlid Reach RX connects to the most surveying apps over Bluetooth Low Energy. The app usually uses the Internet connection on your device to access the corrections stream and send it to the rover over Bluetooth. Reach RX eliminates the chance of getting a wrong setup, as it doesn’t require any configuration. Now you can trust collecting and staking out points to your team members even with no in-person training.
Emlid Reach RX has an incredibly compact design. The pocket-sized rover weighs just 250 grams. You can take Reach RX wherever you go—carry it in a backpack pocket or attach it to your clothing. Reach RX features IP68 ingress protection. The rover operates at temperatures ranging from -20 to +65 °C (-4 to 149 °F).
The Reach RX battery gives you 16 hours of work on one charge. The receiver charges from a power bank, USB wall charger, or a computer USB port over Type-C.
With Global Mapper Mobile Pro on an Android device, simply enable Bluetooth and pair the mobile device to the Emlid Reach RX unit, and in Global Mapper Mobile Pro, use the Advanced GPS > Connect to Device option and select the paired Reach RX to see the advanced position information and begin collecting high-accuracy data. This simple setup process along with the lightweight and easy-to-maneuver Emlid Reach RX makes the setup for field data collection an incredibly simple workflow.
With the two essential parts of GIS data, information and position, taken care of by Global Mapper Mobile and Emlid, field data collection has never been easier. For more information on the Emlid Reach RX and other available devices, check out the Emlid website. To create a Feature Template and begin data collection with Global Mapper, download a 14-day free trial of the Global Mapper desktop, and get Global Mapper Mobile from the App Store or Google Play Store.