How to Upload a Polygon to Gnss

The accuracy required when collecting location depends on the project y'all are working on. For some projects, such equally damage assessments, points within ten anxiety of the impairment may provide enough data. For other projects, such as managing underground pipelines, the location collected must be within a few centimeters of the actual location. When collecting location using a device's location service, position information can be adamant from various sources, such equally GPS, cellular, Wi-Fi, or Bluetooth networks. The accuracy of these sources varies, and the device's location service is not e'er reliable. For those who perform data collection that requires better accuracy and reliable quality control, using a professional person-class or loftier-accurateness GPS receiver is ordinarily the best option.

Global Navigation Satellite Arrangement (GNSS) is the standard generic term for navigation satellite systems. GNSS receivers are capable of using various navigation satellite systems, while GPS receivers can only utilize the navigation satellite system called the Global Positioning System. Due to the widespread use of the term GPS to refer to both kinds of receivers, the term GPS is used as the generic term in this aid.

A high-accurateness GPS receiver precisely calculates geographic locations using data from GPS satellites. The accuracy of these receivers ranges from submeter to centimeter, depending on their ability to track and procedure satellite signals. GPS satellite signals are transmitted on different frequencies. The more frequencies that the GPS receiver uses—and, consequently, the more signals information technology receives—the more than accurate it is. This is also true for GNSS: the more systems the receiver uses (and the more signals information technology receives), the more accurate it is. Today, multiple navigation satellite systems are available. However, usually the more accurate a GPS receiver is, the more than expensive it is and the more hard it is to conduct in the field. Y'all tin likewise improve the accuracy of your position data through differential corrections of the data, supported past some receivers and covered later in this topic.

Consummate the following steps to use a high-accurateness receiver with Collector:

• Prepare your data to record GPS metadata
• Cull a receiver
• Configure your receiver
• Connect your receiver to your device
• Configure Collector to use the receiver:
  • Fix your receiver equally the location provider
  • Set up a location profile (optional)
  • Specify the required accuracy and confidence
  • Enable GPS averaging (optional)
• Postprocess recorded altitudes (z-values)

Prepare your data to tape GPS metadata

In add-on to geographic coordinates, you can as well save other GPS metadata associated with a feature, such every bit its accuracy and fix blazon. Storing this metadata tin exist valuable to assess information quality and ensure data collection standards have been met. If you include GPS metadata fields in your point feature layer, Collector can write GPS metadata to the respective fields when editing indicate features. Y'all should also configure the feature pop-up to hide some of the data from your mobile workers.

While this topic is focused on high-accuracy receivers, these steps enable recording the metadata from whatever GPS, including the internal GPS of a device. If using the internal GPS, not all metadata fields are populated.

Hither are a few things to go along in mind earlier configuring GPS metadata storage:

• GPS metadata is populated on point layers only.
• GPS metadata is cleared if the point's location is provided or updated without using the GPS or while metadata is not available.

The recommended fashion to add the fields depends on how you prepare your layers:

• If you apply templates in ArcGIS Online or ArcGIS Enterprise, check the Capture GPS receiver information check box while creating your feature layer.
• If you lot employ ArcGIS Pro 2.2 or afterward, use the Add GPS Metadata Fields tool after creating your feature form.
• If you utilize ArcMap or a version of ArcGIS Pro before than two.2, use the Python scripts available on GitHub.

Supported GPS metadata

The following GPS metadata values are recorded by Collector when using a configured feature layer:

• Receiver name
• Breadth—Position received from the GPS receiver prior to applying information transformations in the location contour
• Longitude—Position received from the GPS receiver prior to applying data transformations in the location profile
• Altitude—Ellipsoidal elevation received from the GPS receiver (not orthometric height, every bit used for z-values)
• Prepare time
• Direction of travel
• Speed (km/h)
• Azimuth
• Position source

If using a single GPS location to set a bespeak's location, the following metadata values are besides recorded:

• Horizontal accuracy
• Vertical accuracy
• PDOP
• HDOP
• VDOP
• Fix type
• Correction age
• Station ID
• Number of satellites

If performing GPS averaging to fix a indicate's location, the following metadata values are also recorded:

• Average horizontal accurateness
• Average vertical accuracy
• Number of positions averaged
• Standard deviation—An indication of the variation in distance between your final, averaged location and each private location recorded during averaging. A loftier value indicates your position was influenced by outliers.

Y'all tin cull which of these yous record with your data: the values are ignored for any fields yous don't add to your feature layer. Similarly, you can prepare your data for single GPS locations, averaged locations, or both: when averaging is enabled, the associated fields are populated and those for unmarried location collection are left blank, and vice versa.

If you enable a 95 percent confidence level for accuracy in the Collector settings, a 95 percent confidence level is used to determine if your accuracy is adequate for data collection. The recorded accuracies are still calculated using root mean square (RMS). As such, the level of confidence in the recorded accuracies is 63 percent to 68 pct for horizontal accuracy and 68 pct for vertical accuracy.

Choose a receiver

Collector tin brand use of the GPS congenital into your device or you tin add an external GPS receiver to obtain high-accuracy data. There are many GPS receivers available on the market; however, non all of them work directly with Collector. To use a GPS receiver with Collector, the receiver must support the output of NMEA sentences. To meliorate the accurateness of your positions, consider using a GPS receiver that supports differential corrections. If y'all are using an iOS device, yous must as well choose one of the GPS receivers supported on iOS. While Esri doesn't publish a list of supported GPS receivers for Android, a listing of receivers used in testing Collector on Android is provided.

Tip:

Most high-accurateness GPS receivers support the NMEA sentences that Collector uses; withal, it's recommended that yous check whether your receiver supports these NMEA sentences in the receiver'southward user manual earlier you lot try to connect it to Collector.

NMEA support

NMEA 0183 is the data specification standard that Collector uses to communicate with GPS receivers. NMEA messages contain lines of data called sentences. Collector derives GPS information such as latitude, longitude, pinnacle, and fix type by reading specific sentences in NMEA messages.

Collector supports NMEA four.00 and 4.x. Information technology can read the following NMEA sentences:

• GGA: Time, position, and set-related data
• GSA: GNSS DOP and active satellites
• GSV: GNSS satellites in view
• RMC: Recommended minimum specific GNSS data
• VTG: Course over ground and ground speed
• GST: GNSS pseudorange error statistics

If Collector receives GST sentences, which contain accuracy information for a particular coordinate, it uses them to make up one's mind accurateness. By default, the horizontal and vertical accurateness numbers are specified in root hateful square (RMS). The level of confidence using RMS is 63 percent to 68 percent for horizontal accuracy, and 68 percent for vertical accuracy. If the 95% confidence accuracy setting is enabled, Collector applies a conversion factor to the RMS calculation and reports horizontal and vertical accuracy with a 95 pct confidence level.

The internal GPS of some Android devices outputs NMEA. If a device outputs invalid NMEA, Collector uses the accuracy reported by the device's location service.

Estimated accuracy

If Collector doesn't receive a GST sentence from a GPS receiver, only does receive a GSA sentence, Collector estimates accuracy using horizontal dilution of precision (HDOP) and vertical dilution of precision (VDOP). The estimated horizontal accuracy is calculated by multiplying HDOP past four.7, and the estimated vertical accuracy is calculated by multiplying VDOP past 4.7.

Differential corrections

To better the accuracy of your positions, consider using a GPS receiver that supports differential corrections. Differential correction technology further improves accuracy past leveraging reference stations, which are also known as base stations. A reference station is another GPS receiver that is established on a known location. The reference station estimates its location based on satellite signals and compares this estimated position to the known position. The deviation between these positions is practical to the estimated GPS position calculated by the user's GPS receiver, besides called the rover, to get a more than authentic position. The user'south receiver must be located inside a certain altitude of the reference station for differential corrections to occur. Differential corrections can exist applied in real fourth dimension in the field or when postprocessing data in the role.

While Collector stores the information to utilize in postprocessing, it doesn't directly support information technology.

Differential corrections tin can be provided by public or commercial sources. One of the most widely used and publicly accessible real-fourth dimension correction sources is the Satellite-Based Augmentation System (SBAS), which is also commonly referred to equally the Wide Area Augmentation System (WAAS) in the United states. It is free to use SBAS, only your GPS receiver must support information technology. Using commercial correction services typically requires a subscription and may too crave purchasing a particular type of GPS receiver that can receive these correction signals. See "Differential GPS Explained" in ArcUser for more data.

GPS receivers supported on iOS

To directly connect a Bluetooth receiver with an iOS device, the receiver must be part of the MFi program besides as support the output of NMEA sentences. The post-obit receivers tin can be used directly with Collector on supported iOS devices.

Tip:

To discover out the version of firmware your GPS receiver uses, pair your receiver with your device, open up your device's General > Most settings, and tap the proper name of your paired receiver.

• Bad Elf GNSS Surveyor, GPS Pro+, GPS Pro, and GPS for Lightning Connector

  The GNSS Surveyor and GPS Pro+ require firmware version 2.1.xl or later. The GPS Pro requires firmware version 2.0.90 or later. The GPS for Lightning Connector requires firmware version 1.0.24 or later.

• Dual XGPS160—Firmware version ii.5.4 or later
• Eos Pointer Lite, Arrow 100, Arrow 200, and Pointer Gold—Firmware version 2.0.251 or later
• Garmin GLO and GLO 2

  The GLO requires firmware version 3.00 or afterward and the GLO 2 requires firmware version 2.1 or later.

• Geneq SxBlue II and SxBlue III—Firmware version ii.0.251 or later
• Juniper Systems Geode—Firmware version one.0.0 or subsequently
• Leica Zeno GG04 plus—Processor lath firmware version 1.0.20 or later
• Trimble R1, R2, and R10 Model 2

  The Trimble R1 requires firmware version five.03 or later on, the Trimble R2 requires firmware version 5.fourteen or later on, and the Trimble R10-2 requires firmware version 5.34 or later.

  You must configure these receivers directly in Collector. Don't utilise the GNSS Condition app provided by Trimble. Meet Trimble configuration on iOS.

GPS receivers tested on Android

Collector works with whatever receiver supported on Android that outputs NMEA0183 sentences. While the development team doesn't certify whatever device, the following is a list of devices it has used:

Caution:

This is not a comprehensive listing of all devices that work with Collector.

• Bad Elf GNSS Surveyor, GPS Pro+, and GPS Pro
• Carlson BRx6+
• Dual XGPS150A and XGPS160
• Eos Pointer Lite, Pointer 100, Arrow 200, and Arrow Gold
• Garmin GLO
• Juniper Systems Geode
• Leica GG03, GG04, and Zeno 20
• Spectra Precision SP20, SP60, SP80, and SP85
• Trimble R1, R2, R8s, R10, R10 Model 2, R12, Goad, TDC100, TDC150, TDC600, and Nomad 5

  Y'all must apply Trimble Mobile Managing director to configure your receiver. Do not apply the Trimble GNSS Condition app.

Configure your receiver

Non all receivers that support the output of NMEA sentences are configured to practice so out of the box. The device'due south user manual should take instructions on how to configure information technology to output NMEA.

If you'll be using real-time kinematic (RTK) positioning, you lot demand to provide access information for the correction source being used. For Trimble devices used with an iOS device, yous'll provide this data in Collector as function of setting upwards the location provider (encounter Trimble configuration on iOS). For other GPS devices, you'll use their companion app and can reference the device's user manual for details.

Connect your receiver to your device

Collector supports receivers integrated into devices as well every bit external receivers connected via Bluetooth. If your receiver is integrated into the device, go along to the side by side section, Gear up your receiver every bit the location provider. If you lot are using an external receiver, follow these steps to connect it to your device:

1. Verify that your GPS receiver is compatible with Collector.

   Your receiver must support the output of NMEA sentences and be configured to practise and then. See Choose a receiver and Configure your receiver. These instructions must be completed before connecting the receiver to Collector.

2. Plough on your receiver and place it almost your device.

   Go to your device's Bluetooth settings and view the available devices. Await for your receiver'southward name to announced in the listing.

   Tip:

   If your Bluetooth receiver doesn't appear in the list, brand sure information technology isn't connected to another device.

   • To disconnect your receiver from an iOS device, in the device's Bluetooth settings, tap the information icon next to the receiver, tap Forget This Device, and tap Forget Device.
   • To disconnect your receiver from an Android device, in the device's Bluetooth settings, tap the settings icon side by side to the receiver, and tap Unpair or Forget.
3. Tap the receiver's proper name to pair it with your device.

Set your receiver equally the location provider

In one case your GPS receiver is connected to your device, specify that you want the receiver to provide GPS locations in Collector. Once a receiver is chosen, this is the merely source of positions that is used until a new receiver is chosen.

1. While viewing the Maps listing, tap Profile .
2. In the Location section of the contour, tap Provider.
3. If your receiver isn't listed, add together it by completing the following steps:
   1. Tap Add together to display a list of paired receivers.
   2. Select your receiver.
   3. If y'all are mounting the receiver to a pole or vehicle, enter the antenna elevation.

      This is of import if you use the distance of your positions.

   4. If you are using a Trimble R1, R2, or R10-2 on an iOS device, encounter Trimble configuration on iOS.
   5. Tap Done.

   You lot are returned to the Location providers list and your receiver is listed.

4. Tap your receiver in the Location providers list.
5. If you demand to change the antenna height, view the details of the provider, provide a new antenna pinnacle, and tap Done.
6. Return to your profile, and return to the Maps list.

Trimble configuration on iOS

If yous are using a Trimble R1, R2, or R10 Model 2 with an iOS device, configure the correction service for the device in Collector. Equally the map author, y'all should either ready up the location provider in Collector or provide to your mobile workers the correction source (for case, NTRIP or RTX) and whatsoever information needed to connect to it (such as server URL, port, and perhaps mount indicate).

When working with Collector, you won't utilise the GNSS Status app provided by Trimble. On iOS, you must configure your receiver in Collector, and on Android, you must use Trimble Mobile Manager to configure your receiver.

1. If you haven't already, set your receiver as the location provider.

   At step 3d, you'll consummate the boosted steps shown in this department.

2. In the details for your receiver, tap Source and provide the source of the corrections. For case, Straight IP, NTRIP, RTX, or SBAS.

   In one case selected, y'all see the details for your receiver over again. In the Existent-time correction section, yous'll see the configuration data your correction source requires.

3. If using RTX or SBAS, your configuration is complete. Cease setting your receiver as the location provider.

   RTX supports corrections over net and satellite connections. If internet connectivity is non available, satellite corrections are used.

4. If using DirectIP or NTRIP, tap Server, provide the base station URL and port, and tap Connect.
5. If using NTRIP, tap Mount betoken and choose the mount point y'all demand to connect to. If prompted, provide your user name and password.
6. Finish setting your receiver as the location provider.

Tip:

If you are not seeing the accurateness you await later setting up your location provider, review your configuration (tap Info for your receiver in the Location providers listing). Poor accuracy can be an indicator of invalid settings. It can also indicate a bad connection.

Prepare a location profile (optional)

Once y'all have connected your receiver, your mobile workers need to use a location profile to define the coordinate system of the data from the receiver and apply a datum transformation to the data if one is required. If you are using differential corrections and the location provided to you is based on a unlike geographic coordinate system than your map, you must provide datum transformation information. See Datum transformations for details.

The location profile applies to both internal and external receivers. It's recommended to use a location profile when you're using a correction service. If you lot don't ready a location profile, the default contour is used. The default profile assumes that provided locations are in the WGS 1984 Web Mercator (Auxiliary Sphere) [WGS84] coordinate organisation.

When using a location profile other than the default, basemaps that don't match the spatial reference of the location contour are unavailable.

1. While viewing the Maps list, tap Profile .
2. In the Location department of the profile, tap Profile.
3. If your profile isn't listed, add it by completing the following steps:
   1. Tap Add to display a listing of coordinate systems.
   2. In the GNSS coordinate system list, tap the coordinate organisation used past your receiver's correction service. You tin search past the name or ID of the coordinate system to filter the results in the listing. If using an Android device, tap Next.
   3. In the Map coordinate arrangement list, tap the coordinate system used by your map (determined by the basemap it uses). Y'all can search by the name or ID of the coordinate system to filter the results in the list. If using an Android device, tap Side by side.

      Caution:

      Some projected and geographic coordinate systems accept the same name. Make sure yous choose your coordinate arrangement from the correct category.

   4. If a datum transformation betwixt the coordinate systems of your receiver's correction service and your map is not required, tap Next (Android) or Done (iOS) and skip to stride g (naming the contour).
   5. If a datum transformation between the coordinate systems of your receiver's correction service and your map is required, fix the map extent to the area where data is going to be nerveless and tap Next.

      You can merely specify the data collection area when your device has access to online data via Wi-Fi or a cellular network. When offline, specifying a data collection area is skipped.

   6. Tap the desired datum transformation in the listing of bachelor transformations and tap Next (Android) or Done (iOS).

      If y'all are on an iOS device and the datum transformation is grid based and needs to exist downloaded, Download displays next to it. Tapping the transformation downloads the required files before you can continue making your location profile. If you'd rather copy the files directly to the device (sideload them), you need to do so before creating the contour.

      Tip:

      On Android, grid-based datum transformations must be copied directly to the device before creating the profile. Back up for downloading them is coming to Android.

      The datum transformation listing is sorted past relevance, with the well-nigh relevant transformation listed showtime. Collector uses the GNSS coordinate organization, map coordinate system, and (if provided) the extent where information is going to be collected to provide and sort this list of applicable datum transformations.

   7. Provide a proper noun for your profile and tap Add (Android) or Save (iOS).

   You lot are returned to the Location profiles list and your contour is listed.

4. Tap your profile in the Location profiles list.

   Tip:

   To verify the profile's coordinate systems and transformation, view the details of the profile. On Android, access the details through the Overflow menu . On iOS, tap Info .

5. Return to your contour, and return to the Maps list.

Datum transformations

The locations provided by your receiver may be based on a different geographic coordinate arrangement than the map you are using in Collector. If this is the example, use a datum transformation to maintain the accuracy of your data.

When you receive a location from a GPS and use information technology to add or update a feature, that location is in geographic coordinates that are referenced to a geographic coordinate system (GCS). Your map likewise has a coordinate system, determined by the basemap information technology uses, which may be a GCS or a projected coordinate system (PCS). If the location and map are based on unlike geographic coordinate systems, the location existence added or updated must be transformed to match the map's coordinate organisation. This conversion process is called a datum transformation. While there are both horizontal and vertical datum transformations, Collector but supports horizontal transformations.

Since coordinates, maps, characteristic layers, and databases all have coordinate systems, a datum transformation (or transformations) should occur someday your coordinate system doesn't lucifer that of where the information is being used: between the GPS and the map, the map and the feature layer, or the characteristic layer and the geodatabase. Whenever a datum transformation is used, error is introduced into your locations. By choosing the right coordinate systems for your map, characteristic layers, and databases, you can limit the number of transformations, as well as the error introduced each time. See ArcGIS Geographic and Vertical Transformation Tables for details on the error introduced through various transformations.

If the coordinate systems don't match and no datum transformation is provided, the data is used as it is provided. As a result, its location won't align with the locations of other information already in place. Similarly, you'll see incorrect positions if you provide the wrong datum transformation.

In Collector, yous can prepare a location contour prior to collection and specify the specific datum transformation to use. While creating a location contour, the coordinate systems of both the GPS data and the map are specified. Based on this information, yous are presented with only relevant transformation methods, with the recommended method listed first. As the map author, y'all should either prepare upward the location provider and contour in Collector or provide to your mobile workers the coordinate systems of the GPS and the map, as well as the transformation method they should use when they configure Collector.

If y'all are using one of the basemaps provided by Esri on ArcGIS Online, it is in the WGS84 coordinate organisation. Similarly, WGS84 is the default coordinate organisation for GPS information received in Collector. If you are using an ArcGIS Online basemap and the default location provider, no datum transformations are necessary in Collector.

Grid-based transformations

Filigree-based transformations are supported in Collector. These transformations utilise files to calculate positions and crave the files to be on your device. To use a grid-based transformation, the files must exist downloaded (iOS-only) or copied (sideloaded) onto your device.

• On iOS—If your datum transformation is grid based and requires files, you lot'll exist prompted to download it when setting up your location profile. If you lot'd rather copy the files directly to your device, you tin can do so.
• On Android—You must copy whatsoever files required for a filigree-based datum transformation direct to your device.

To re-create the files directly to your device, go them from an installation of ArcGIS Pro or ArcMap (yous may need to install the Coordinate Systems Data setup in add-on to the main product setup to get specific grid-based transformation files). Copy them to your device in one of the following ways:

• On Android—Plug your device or SD card into your computer. Using a file explorer on your reckoner, scan to \Android\data\com.esri.collector\files\PEData (if that folder doesn't exist, create it). Copy the files for the grid-based transformation to that PEDdata folder.
• On iOS—Employ the Files app or iTunes to copy the files for your grid-based transformation to the documents for Collector, placing them in a PEData folder.

  Tip:

  To update a folder in the app's documents using iTunes, first salve the folder from the device, make your changes to it, and then upload information technology. The new binder replaces the previous one.

You must maintain the folder structure in the PEData folder the same equally it is structured for ArcGIS Pro or ArcMap. For example, to copy the files for the Old_Hawaiian_To_NAD_1983_HARN_Hawaii + ~NAD_1983_To_HARN_Hawaii transformation, add to the PEData folder on your device a binder named harn, containing the files ohdhihpgn.las, ohdhihpgn.los, hihpgn.las, and hihpgn.los.

Specify the required accurateness and confidence

Your organization may require that all information collected encounter a specific minimum accuracy and confidence interval. In Collector, you lot can set the required accuracy of GPS positions and whether the positions need to meet a 95 percent conviction level. This ensures that data you lot collect meets your organization's information collection standards.

For detailed steps, see Configure Collector—Specify the required accuracy and confidence.

This topic assumes you lot'll gear up up the devices for your mobile workers. If this is non the example, make sure you communicate to them what accurateness to require and whether they need a 95 percentage conviction level.

If your mobile workers use decimal degrees, by default coordinates are displayed with six decimal places of precision. This tin can be configured as role of the units setting in Collector.

Enable GPS averaging (optional)

Your organization may require that you collect a number of points for a unmarried location and average their information to get a final location and accurateness. In Collector, you can set the required number of points to be averaged to become a single location. Whatsoever time y'all use GPS location in your data collection, the required number of points will be collected and averaged. When enabled, averaging is done for point features too as for the individual vertices of lines and polygons.

For detailed steps, run into Configure Collector—Enable GPS averaging.

This topic assumes yous'll fix the devices for your mobile workers. If this is not the instance, make sure you communicate to them if they should enable GPS averaging and if so, how many points to average.

Postprocess recorded altitudes (z-values)

When recording altitude, Collector records orthometric height based on the geoid model of your receiver (oftentimes EGM96, but come across your device'south user manual). If yous require a different geoid model, postprocess the values to use the required geoid model.

Your receiver is now providing locations to Collector. Every bit you collect data, you lot will provide your arrangement with high-accuracy data that meets its standards.

Related topics

• Configure Collector

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Source: https://doc.arcgis.com/en/collector/ipad/help/high-accuracy-prep.htm

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