Gps Parcela User Instructions

CONTENT
- Introduction
- Start
- Registering a user account
- Login
- Settings
- Menu
- Land parcel data
- How to enter land parcel coordinates
- Navigation to a land parcel
- Precise locating of parcel corners
- GNSS Receiver - NTRIP Client
- Vanis RTK receivers
- Centimeter GPS accuracy with RTK correction
- Backup and restore
- List of geoportals

INTRODUCTION

Gps Parcela app is intended for all private landowners who want to have on their smartphones or tablets the data of all their land parcels with corresponding maps so they can easily navigate to their land parcels.
The app is also intended for all real estate, precision agriculture and forestry professionals.

The Gps Parcela app has a built-in NTRIP client that allows you to connect to a GNSS receiver using Bluetooth, and to connect to CORS - reference GNSS stations network using Internet.
In this way, the NTRIP client enables centimeter GPS accuracy with RTK corrections.

The app can receive location data (latitude, longitude and others) from two sources.
The first permanent source is the built-in GPS receiver of the smartphone. However, the accuracy of GPS coordinates in this case varies between 1 and 3 meters, which is quite enough for navigation to your land parcel.
An additional source can be an external GNSS receiver that has the capability of RTK correction. In this case, the accuracy of the Gps coordinates is one centimeter, which is necessary to precisely locate the boundary points of your land parcel.

This app is based on the idea that all cadastral data (primarily coordinates) of your land parcel are visually available to you personally via the Internet on the geoportal of your country.
However, there is no possibility that any app has a free access to cadastral data of all geoportals in Europe.
Therefore, with a little effort and with our help, you can type into this app the coordinates that you have read on the geoportal. Definitely this is the most precise way to define the boundaries of your land parcel so that you can use all features of this app.

START

After the app gets started, you will see on the screen a map of your location and a bottom toolbar with icons.

 

From left to right, there are the following icons: User, Data, My land parcel, My location, GNSS Receiver, Settings, Menu.
Right of the icons there are the following data:
Distance from My location to My land parcel, only if the land parcel is shown
Distance traveled, only if route recording is on
Longitude and Latitude of My location, in round brackets
Gps accuracy, in square brackets, in meters
Number of visible satellites for position calculation, in curly brackets
My speed, in m/s
Gps source ( satellite, wi-fi,…)
At the start of the app, it is necessary to wait in the open space for some time (about 10-15 seconds) to get the GPS signal and GPS coordinates of your location.
First, select one of the following languages in the Menu window: English, German, Italian, Croatian, Slovenian, Serbian, Czech, Slovak, Polish, Spanish, Portuguese, French. The default language is English.
Tap the User icon to create your user account with your e-mail address and password. The following window will then appear.

In this window you can do the following:
1. Start registering your account
Tap the "or continue to register" button and a new registration window will appear.
2. Transfer license from old to new smartphone
Enter the login information you used on your old smartphone. Login information is: e-mail and password. Tap the "Login" button. Previously, you should have deactivated your license on your old smartphone.

REGISTERING A USER ACCOUNT

At the first start of the app you will have the option to sign up for a user account with the following data that you need to enter: your e-mail address and password, your name and address.
Your e-mail address and password are tied to your smartphone only and your email address and password can not be used to sign in to the Gps Parcela app on another smartphone or tablet. We will never share your information with third parties.
Tap "Create a user account" button.
You need the account only if you want to subscribe for usage of Gps Parcela app for your land parcels using geoportal reference coordinates. The annual subscription amount is 29 EUR including VAT.
Once you've created your account, you'll receive an email containing an offer for subscription with the payment instructions.
If you do not accept our offer, your account will be automatically cancelled.
After signing up for the user account, you can use until the end of the day all the app functions without making a payment.
You can make the payment using PayPal.
Please click on the link below to pay with PayPal.

LOGIN

Tap the User icon again to see changes to your payment status.

Once we receive your payment, you'll be able to fully use the app.
Tap the "Login" button to let the app change your payment status.
After that, you'll see the message with the validity end date of your user account.
You can also order coordinates for your cadastral parcel from our web server.
This is an additional service we provide to help you use this app.
Enter the full name of the cadastral municipality and the cadastral parcel number.
Tap the "Send inquiry" button and this will automatically send your request to our email.
The subscription price for using the Gps Parcela app does not include downloading files with the coordinates of your cadastral parcels from our web server.
You can download the coordinates in a file from our web server under certain terms that you will receive from us in the email. The price of creating a file with coordinates for one of your cadastral parcels is 10 EUR. The coordinates will be read from the geoportal of your country (if available) according to the terms of the User Instructions.

SETTINGS

Tap the Settings icon

Select a country and a reference coordinate system for your land parcels.
The list of countries supported by this app is shown at the end of this guide. The list of countries is a drop down list.
Tap the "List of geoportals by country" button and a web page with a list of geoportals will appear.

Tap the "License transfer" button and you will deactivate your license that can be reactivated on another (or the same) smartphone. The license consists of the following data items: email and password.
You can activate a deactivated license on another smartphone by entering your email and password when registering a user account and then tapping the "Login" button. To restore the license to the first smartphone, tap the "License Transfer" button again on the second smartphone, then tap the "Login" button on the first smartphone. If you are returning licenses to the second smartphone, tap the "License Transfer" button on the first smartphone again, and then tap the "Login" button on the second smartphone.

Tap the "Subscription" button and a window will appear in which you can purchase a subscription to the Gps Parcela app in the Google Play Store using the payment method from your Google account.

Tap the button "Request to delete your Gps Parcel account" and a web page will appear where you can send a Request to delete your Gps Parcel account.

MENU

Tap the Menu icon

- Tap the "Land parcel data" button or the Data icon to edit the land parcel data in a new window.
- Tap the "Precise locating of parcel corners" button and a new window will appear.
- Tap the "GNSS Receiver - NTRIP Client" button and a new window will appear.
- Tap the "Backup and Restore" button and a new window will appear in which you can back up and restore files.

Select one of the following languages: English, German, Italian, Croatian, Slovenian, Serbian, Czech, Slovak, Polish, Spanish, Portuguese, French. The default language is English.

LAND PARCEL DATA

Tap the Data icon to edit the land parcel data in new window.

In this window you can:
create a land parcel file by entering the coordinates,
update the entered coordinates,
download the cadastral parcel coordinates from our web server,
transform the reference coordinates to Gps (WGS84) coordinates,
get the land plot area and boundary line lengths,
save the land parcel file in your local smartphone storage folder,
open a land parcel file from the local smartphone storage folder,
delete the open land parcel file from the local smartphone storage folder
close the open files with "Clear" button,
show the map of the open land parcel file.
You can open and display up to 10 land parcels simultaneously.
The name of the local storage folder is GpsParcela.

HOW TO ENTER THE LAND PARCEL COORDINATES

-First you need to read the coordinates for your parcel from the cadastral map of the geoportal for the selected country and the coordinate system.
-Tap the "Clear" button. In the light blue field under the heading "Point" number 1 will be displayed . Two light blue fields for two coordinates will be empty.
-In each of these two light blue fields you need to enter a single coordinate.
-Tap the "Add" button. The values ​​of the coordinates you typed will be overwritten above in two gray fields. The number 2 adjacent to the "Point" heading field will appear. The adjacent two light blue fields will be empty and ready to enter the coordinates for point number two.
-Enter the coordinates for all points according to the procedure described above. Each point has its own ordinal number.
-The points with the coordinates can be moved up and down by tapping the up and down buttons.
-You can change the values ​​of the point coordinates in light blue fields and then tap the "Update" button.
-You can remove the point from the light blue fields by tapping the "Remove" button.
-You can transform values ​​of the coordinates in light blue fields to Gps (WGS84) coordinates by tapping the Globe icon. With the first tap, the coordinates for longitude and latitude will be shown in the decimal format and with the second tap the Gps coordinates will be shown in the clock format "degree:minute:second"
-After you have entered the coordinates for all points, type the land parcel file name into the light blue field under the heading "Name of the land parcel". Tap the "Save" button. The parcel file name will then appear in the parcel file list. The file name can contain only letters, digits, and a minus sign.
-You can see the parcel map by tapping the "Display" button or by tapping the My parcel icon.
-You can scroll up and down the list of land parcels by tapping the up and down buttons. Also the land parcels list is a drop down list.
-Tap the "Open" button, and the land parcel file name from the gray field will open, which means that the data for all points will be in the list of points. At the same time, the value of the land plot area will be shown and the boundary line lengths will be listed under the heading "Distance".
-Name of the opened parcel file will appear in a light blue field under the heading "Name of the land parcel".
You can delete this parcel file by tapping the "Delete" button.
-Tap the "Download" button if you have ordered the cadastral parcel coordinates from our web server.
You will see a list of your ordered parcels (one or more) from our web server.
Select a name from the list and tap the "Select a land parcel" button
and your parcel file will be downloaded from our web server in your local smartphone memory.
After that, the ordered file will appear in your land parcel list.
Tap the "Display" button.

NAVIGATION TO A LAND PARCEL

display the land parcel map

Tap the My land parcel icon to display map of the selected land parcel.
The land parcel is labeled with a yellow color marker.
Tap the My location icon to display map of my location
The current location is marked with a green marker.
However, if you stop moving (the speed is zero) then the automatic averaging for longitude and latitude in the last 10 readings of Gps points for which the accuracy is less than 5 m (for Android) starts automatically. Points with accuracy greater than 5 m are not taken into account. The location marker color becomes red and the average value for longitude and latitude is displayed in the round brackets , which results in a higher accuracy of Gps coordinates reading.
You will know with relative accuracy that you are on your land parcel when a green marker (that indicates the position of your smartphone on the map) shows that you are within the boundaries of your land parcel map.
This app can not be used for geodetic surveying.

HOW TO GET COORDINATES

of your cadastral parcel from geoportal

To precisely define the coordinates you need to use a PC or laptop with a mouse instead of a smartphone that has too little screen for this purpose.
Click on a link from the geoportal list and there you can easily get the relatively accurate reference coordinates for the cadastral parcel from the displayed cadastral map.
There are two possibilities to do so, depending on the chosen geoport.
The first possibility is to enter the full name of the cadastral municipality and the cadastral parcel number and then click on an icon that leads you to view the map of your land parcel.
The second possibility is to zoom in the displayed map until the boundaries of the parcels appear, where you can recognize your land parcel by its number.
In both cases, move the mouse over a corner point and you will be able to read on the screen the corresponding reference coordinates. Then you should enter the coordinates for each corner point into the app directly.
You need to know that the accuracy of data and maps is not absolute because it depends on a lot of factors. For example, cadastral maps on geoportals are not always absolutely accurate and usually the coordinates have a meter accuracy. Although in most cases your land plot corresponds to the real situation on the ground, it may still happen that this is not always the case, because of inaccurate input data.

read more: Accuracy of GPS Data ...

PRECISE LOCATING OF PARCEL CORNERS

Tap the Menu icon and the "Precise locating of parcel corners" button

To precisely locate the parcel corners, the Gps Parcela app applies the RTK method to correct the accuracy of GPS coordinates using a bluetooth GNSS receiver and Internet access to a network of reference stations.
Open the land parcel file and select the target point. Tap the 'Start precise navigation' button and continue to maps.
Walk towards the target point by following the line between the current point and the target point

GNSS RECEIVER - NTRIP CLIENT

Tap the Menu icon and the "GNSS Receiver - NTRIP Client" button

Initial setup of GNSS receiver and network of reference GNSS stations
Connect the receiver to a portable battery (power bank) with a USB cable. We recommend a 10,000 mAh power bank.
You should first pair your smartphone and GNSS receiver via Bluetooth connection by tapping the Bluetooth search icon.
The Gps Parcela app supports the following RTK GNSS receivers:
- Vanis RTK Handheld Surveyor
- Vanis RTK Calibrated Surveyor
After some time, the name of the GNSS receiver will appear in the GNSS receiver selection list. In case of Vanis RTK receiver, the name will be RTK_GNSS_xxx where xxx is the number. Select the name of the receiver from the list. Tap the "Connect to GNSS receiver" button. A pairing request will appear. Accept the pairing and enter the password 1234.
After that, a Bluetooth connection will be established and the coordinates of your location will be displayed. These coordinates are not corrected. Tap the "Save" button .

To set up the network, you need the following data:
IP address, port number, mount point, username and password.
You can get this data from the service that provides RTK corrections.
The mount point is the name of the nearest reference GNSS station from which you will receive the RTK correction. It should be a station that is no more than 35 km away from you if you want accurate corrections. In this case, you do not need to check "Send receiver position to the network". The list of mount points can be found on the website of the service.
However, there are services that choose the nearest reference station for you, but for that they need the coordinates of your location. In that case, you should check "Send receiver position to the network". Also in this case, the service type is entered in the mount point field. Usually the service charges for its services per minute of network connection, for example 0.06 EUR/minute.
There are also free services and the most famous global free service is www.rtk2go.com. In this case, no log-on account is required, just connect with this data:
IP address 3.143.243.81
Port number 2101
Username: your valid e-mail address
For the password enter “none”
Enter the valid mount point name
Tap the "Save" button and your data will be saved.
Please note that rtk2go.com does not have a sufficient number of reference stations for all parts of every country in Europe.

Working with RTK correction
Tap the "Connect to GNSS receiver" button.
Tap the "Connect to the network" button
If the connection is successful, the duration of the connection will be displayed in the "C.T" field, and the arrival time of the message with RTK correction will be displayed in the "R.T" field.
The data sent by the GNSS receiver will also be displayed (in the field below the "Connect to GNSS receiver" button).
These are: latitude, longitude, and a letter as a mark of the correction quality
The quality marks are as follows:
N- no correction, orange marker on the map
D- bad correction, magenta marker on the map
E- floating correction, azure marker on the map
F- fix correction, blue marker on the map
Two markers will be displayed on the map:
green marker with location data obtained from smartphone, and
color marker of RTK correction quality with location data obtained from GNSS receiver.

VANIS RTK RECEIVERS

The Gps Parcela app allows connection to the RTK receiver using Bluetooth, and connection to the CORS - reference GNSS stations network using Internet.
In this way, The Gps Parcela app enables centimeter GPS accuracy with RTK corrections.
The Spanish electronic company ArduSimple produces Vanis RTK receivers for VANIS d.o.o. Croatia

Visit the ArduSimple web store and get the Vanis RTK receiver directly:

* Vanis RTK Handheld Surveyor Kit, recommended for Gps Parcela app

CENTIMETER GPS ACCURACY WITH RTK CORRECTION

The Gps Parcela app has a built-in NTRIP client that allows you to connect to a GNSS receiver using Bluetooth, and to connect to CORS - reference GNSS stations network using Internet.
In this way, the NTRIP client enables centimeter GPS accuracy with RTK corrections.

And what is GNSS, RTK, NTRIP,...?
RTK is a technology for correcting and increasing the accuracy of the GNSS system, which provides centimeter accuracy of GPS coordinates.
GNSS is the name for the system of navigation satellites (Global Navigation Satellite System).
There are four GNSS systems: American GPS, Russian GLONASS, Chinese BeiDou and EU Galileo.

A GNSS receiver is a device that simultaneously receives signals from several GNSS satellites (at least 4) and calculates the GPS coordinates (latitude and longitude) of its position on the ground.
The GNSS receiver has two main parts: the antenna and the processor part. The quality of the GNSS receiver depends on the quality of the antenna.
There are 2 types of GNSS receivers:
- a standard receiver that does not have the RTK correction capability and this receiver is installed in smartphones.
- RTK receiver that has the RTK correction capability and this receiver has its own housing.

An RTK GNSS receiver placed at a fixed position with known exact GPS coordinates can be connected to a reference station computer. In this case, this RTK receiver calculates the RTK error as the "difference" between the exact coordinates of its location and the coordinates it calculated based on the received GNSS satellite signals. This error is actually an RTK correction that can be sent to another RTK receiver nearby, which is receiving signals from the same GNSS satellites at the same time. The other RTK receiver can now correct its calculated GPS coordinates with the received RTK correction and then send the centimeter-accurate coordinates to its NTRIP client via Bluetooth connection.

A network of reference GNSS stations is organized in each country or globally as a service for the distribution of RTK corrections.
This service includes NTRIP caster and reference GNSS stations that are up to 70 km apart. NTRIP caster is a web server app that has an IP address.
All reference stations send their RTK corrections every second to the NTRIP caster.
NTRIP clients connect to the NTRIP caster to get the RTK correction of the nearest reference station.
RTK correction is transmitted in a message using the NTRIP communication protocol in RTCM format.

BACKUP AND RESTORE

Tap the Menu icon and the "Backup and restore" button

Gps Parcela app stores land parcel data to internal private storage. Each app has its own internal storage that is only available to that app. In addition to internal storage, there is also external storage that is available to all apps under certain conditions. When the app is uninstalled, its internal storage is deleted and all land parcel data is lost. Therefore, it is useful to back up files from internal storage to a separate backup folder in external storage. For privacy protectin, the user must create or select a backup folder himself. If necessary, the user can restore files from the backup folder to the internal storage of the app.
First you need to choose an existing folder or create a new folder. Then tap the "Copy the file to the backup folder" button or the "Restore one file from the backup folder" button.
The selected file that you can backup, is the file you opened from the list of parcels in the Data window.
You can also copy all the files as a single ZIP file named "Zipped_Parcela_Files" with the date.