An Introductory overview of ArcGIS online

  We believe mapping and web maps are synonymous with the future of spatial data collection, processing and especially dissemination. In line with the mission of the authors of the blog site, tips, exercises and tutorials on creating and sharing web maps will enable the mapping enthusiasts to share data more efficiently.

Disclaimer- We are in no way marketing or promoting esri products. We are non-proprietary and work with softwares based our knowledge about them!!!

ArcGIS Online is an online web map and application platform run by ESRI. It offers many features from basic editing to more complex things like creating web map applications online. It is a cloud storage based system and runs on subscription. ArcGIS online is plugged into ArcMap Desktop so the user can seamlessly transfer data from the Desktop to Online resources as a map package or feature service.

This post will start with the basic question- How do I get to have ArcGIS online so I can practice some of these tips?

Having a ESRI Global Account.
Sign in or register at the ESRI site for a Global Account. The ESRI Global Account automatically entitles the user to a free ArcGIS Online account. This account however is a basic account and lacks some of the features of the Enterprise account.
Apply for a Trial Enterprise Account.
Register for this account as an administrator at the ESRI site. This account comes with the full complement of features in ArcGIS Online but 60 day free trial with limitation to 200 credits.
Subscribe for ArcGIS Online
Just as an addition, ArcGIS Online is not a freeware and it is annual subscription based. Depending on the need of the Organization, there are different subscription sizes to choose from.

Another question is ‘What makes ArcGIS Online so different from ArcMap Desktop’ – In my opinion, three main things
- It is cloud based and ready to share within a network or public.
- The interface and map elements and controls are more in tune with modern cartographic software like CartoDB.
- It comes  with different types of base maps.


Register for your ESRI Global account and you automatically can sign into ArcGIS Online with a Basic Account and practice along with us.

Disclaimer- We are in no way marketing or promoting esri products. We are non-proprietary and work with softwares based our knowlegde about them!!!

The ArcGIS online environment is a lot different from ArcMap and this post will try and familiarize you with the different relevant pages and buttons.

Home page


Sign in and the Home page will open. Two pages are of most relevance to the Basic Account Holder-
red boxed – MAP
green boxed- MY CONTENT

MAP page


This page is the studio where all the web map design and implementation is done. We will take a look at all the elements in the red box on the menu bar.

Add – As indicated from the dropdown list, files are imported into the Map by using this button.

Basemap- Click here and the different types of base maps will be available such as Imagery, Streetmap etc

Save – Click and two options will open- Save and Save As. This will open a Save Map dialog box to fill. Saves the Map and its layers to the MY CONTENT page.

Share- This button allows the User to publish the web map through creating a Share lInk, Embed Map in Web Page or Make a Web Application.

Print- Print the map for presentation.

The Green box is a Search Location bar that allows the User to find geocoded addresses on the Base map.

MY CONTENTS page


Red box- This the default folder created during the registration of the account. The User can add more folders by using the NEW option just above the default folder.

Blue boxed- Add Item – Click on this button and three options will appear - From Computer, From Web and From Esri. This will add items such as GPX files, KML Files and Zipped Shapefiles as files into the folders in the MY CONTENT page. Create- This button will give three options on the dropdown list of the Basic account- Map, Application and File. This allows the User to create maps, applications and scenes from the files in the folders of the MY CONTENT page.

Green box- Share- the User can use this button to change the status of the file- to change from Not Shared to Everyone. Delete- to delete a file in the Folder. Move- move a file between folders. Change Owner- to edit the owner permissions on the map or layer or file.

Note the layer highlighted in brown is a Feature Layer and this service map is not available for a Basic Account.
Guess you have registered for ArcGIS online and are practicing along.

Performing Spatial Query on feature layers in QGIS

A Spatial Query is one made on the spatial element of the database. Unlike a query based on attributes, it is the feature's topology (relationship with other objects in the same geographic extent) of the object that is queried.

Task

This demonstration illustrates the spatial query to be carried out on feature layers in QGIS in order to resolve customer complaints to a Utility Company. The Utility Company has a Tariff Map that delineates areas within a city into High, Medium and Low Tariff Blocks (red boxed).



Subsequently, Customer complaints from Parcels-543,435 and 378 (as seen above) have reached the Company Office about abnormally high utility bills. In order to save time and money, the Company GIS team will analyze the complaints so as to forward the viable complaints to the ground teams.
Steps
Three spatial queries were performed.
- Spatial query to know which Parcels fall within the Low Tariff Block.
- Spatial query to know which Parcels fall within the High Tariff Block.
- And a third Spatial query to ascertain whether there are Parcels that overlap between the Low and High Tariff Blocks.

Procedure
1. Go to Vector >Spatial Query >Spatial Query


2. In the Spatial Query dialog box, we first want to determine which parcels are completely within the Low Tariff Block especially in respect to the complaint from Parcel 543. We Select Source features- PARCELS that are WITHIN target or reference feature- LOW TARIFF BLOCK. Two parcels are highlighted- 302 and 304 but 543 is not highlighted but it falls within the Low Tariff Block. But also note that Parcels 435 and 378 are not highlighted.


3. Right Click on the Parcels layer >Open Attribute Table to see that the Selected Parcels were highlighted.


4. See the Selection of our Spatial Query highlighted in blue.


5. We run another spatial query to ascertain which Parcels are within the High Tariff Block. The result shows that Parcels- 435 and 378 fall within the High Tariff block. Parcel 543 again is not within the High Tariff Block.

6. To further filter the data, we run a third spatial query selecting the Parcels that overlap into the High Tariff Block. Viola! Parcel 543 is selected.



Results of the Spatial Query

7. for Customer Complaints from Parcels- 543, 435 and 378. Read brown box.
8. Hope you enjoyed the post.
    Keep practicing so we can share your experience.

Uploading vector layers from QGIS and store in GPS receiver (USB Port) using DNR GPS

Overview
This post is what I would like to call the USB route to uploading GPX layers from QGIS into a USB Port GPS receiver.
Note-
- The GPS receiver- Garmin Dakota series- comes with only USB Port. If your receiver comes with a serial com port, you can do the upload direct without going through DNR GPS.
- Apart from converting files, DNR GPS also serves as an upload vehicle for GPS receivers.
- The DNR GPS is not acting as a converter in this procedure but an upload vehicle.
- In QGIS, one can digitize layers on the image using GPX file format direct.

Task
We want to create and upload layers (point, line and polygon) from QGIS and store as waypoints, route and track in our GPS receivers. Steps to follow- (a) Trace out waypoint, route and track layers on the image in QGIS; b) Upload to the GPS receiver using DNR GPS.
Note- One can save it straight into the GPX folder in the drive of the receiver but this denies one the opportunity that DNRGPS offers, which is, viewing the contents of the GPX file before upload.

Procedure
1. Launch QGIS. Go to Layer>Create new layer>Create new GPX layer.


2. Digitize waypoint, route and track features (point, line and polygon) on the image. The waypoints are in red, the route in purple and the track in yellow. Make sure the layers are properly saved after digitizing.


3. Launch DNR GPS. Go to File>Load from>File. Navigate to the folder where the gpx file was saved. Open the gpx file from the working folder. A message box will show indicating the file has been successfully loaded.


4. Click on Waypoints and the waypoints created in QGIS will appear. Take a good look at the Tracks(red boxed) and Route buttons(green boxed). Note that the tracks and routes that were created were also uploaded together with the waypoints. Click on them to check the contents.


5. Go to Track and click Upload. Do the same for route and Waypoint. A message box saying Upload Complete indicates the file has been uploaded to the GPS receiver.



6. Disconnect the GPS receiver and check for the uploaded waypoints, route and track.


Hope you are already practicing with the QGIS. Feel free to send your feedback and comments.

Tip- you can double click on the images and it will open in a new window in a larger size.

Uploading Points from a Google image to store as waypoints in a GPS receiver

Overview
Place markers in google earth can be points, lines or area features representing spatial locations . This presentation demonstrates how to place mark locations on a google satellite image, convert their format so one can store them as waypoints in a GPS receiver.


Task
The team has been given the task of identifying and carrying out a physical inspection of empty parcels of land within the city limits. We intend to use this process to map spatial data on the empty parcels and store the locations in our GPS receivers as waypoints. We will then use the GPS receiver to navigate to these waypoints for physical inspection.
Softwares- Google Earth, DNRGPS,
Hardware- Laptop, Garmin Dakota 10 handheld GPS receiver.

Procedure – Three step approach
Step one- Map waypoints from the google image and save as KML file
1. Launch Google Earth. Search for the vicinity of the study area. In the places window, right click>Add>Folder


2. Name the folder – empty plots. Go to the main menu and select the pushpin icon or Add Placemark button (encircled red). A dialog box and a yellow pushpin will appear on the image. Use the mouse to drag the pushpin and position it on the point of interest (in this case, empty plots). Go to the dialog box and name it, notice that the X and Y position of the points are displayed (green box) in the dialog box. Click OK. As you can see, the named point will appear on the image.



3. Select two more points and right click on the empty plots folder>Save place as. Notice that all the just created placemarks are in the empty plots folder.


4. In the save file dialog box, *save type as Kml


  Step two- Use DNR GPS to convert from Kml format to GPX format.
5. Launch DNR GPS and after that connect your GPS device to the laptop or PC. Go to File>Load from>file.



6. Navigate to the folder where the saved Kml file (empty plots) is stored and click open.


7. The place markers from google image still in Kml file format are loaded into DNR GPS


8. Go again to File>Save to>File. We are now converting the Kml file to GPX file format. GPS receivers store gps data as GPX format. A Save To File dialog box will open (no.9)
 

9. In the Save To File dialog box, change the file format to GPS Exchange Format (red boxed) to convert our empty plots kml file to *gpx file format.


Step three- Uploading Waypoints to a GPS receiver
10. Connect the GPS receiver by USB or Serial port. Go to GPS>Connect to Default GPS. If this doesn’t work, try the Find GPS


11. Once the GPS is connected, it will show up on the menu. Go to Waypoint>Upload
 

12. The dialog box will appear to fill in a name for the uploaded data. This process saves the Waypoints in the GPS receiver.


13. A message box indicating complete upload. Disconnect the GPS receiver, power it up and check for the point1, point2 and point3.


hope you liked the posting.

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Querying the attribute tables of feature layers using ArcMap 10.2

Overview                                           Video presentation link
Querying or filtering attribute data in a GIS is technically one of the important parts of using a GIS. Fields contain several kinds of values that are linked to a spatial object. In order to get specific information from these data fields, a selection or query is applied.

Task
Our task in this post is to show you how to Select by Attributes using ArcMap 10.2. By this we mean how to query your attribute tables for particular information on them. We have a point layer consisting of some buildings represented as points. We want to query the attribute table to know which buildings are in a bad repair state and are blue in colour.

Procedure

1. Right Click on the layer > open attribute table.

2. Observe the attribute table contains data of the results of a building state of repair survey. We want to know which point satisfies a selection criteria on this table. Criteria - The Repair_ State is bad and Building_col is blue

3. On the main menu, Click Selection>Select by Attributes.

4. The Select by Attributes dialog box will come up. In this box, we will select the field where the unique values we are querying for lies. We make a common sql statement to execute the query. In green box are the fields we are querying and the unique values are ‘bad’ and ‘blue’(see red box)


5. Right Click on the layer>open attribute table. The point(s) that have the attributes that meet the criteria of the selection will be highlighted on the attribute table.(highlighted in blue)


Video presentation link
Hope you are already getting some practice. Feel free to send your comments.

Querying the attribute table of a feature layer in QGIS

Overview of the task

In our earlier post we showed you how to join attribute data tables in a GIS using ArcMap 10.2.
For today’s exercise, we will be working with attribute data in QGIS and making a Selection by Attributes. Our data comprises a spatial layer of different point features digitized on a paper map of Ibadan municipality. These point features comprise of schools, churches and hospitals. A building repair survey was done in the area by the local authorities and we have section of that in a csv table – Building Repair Survey.

Task

• Join the attribute data to the spatial layer. (In QGIS, we had to invent a runaround way by exporting the shape file out as csv, populating it in excel and returning back as a csv/shape file to QGIS).
• Select on the map which point features where building color is blue.

Procedure

1. Digitize the point features (places shape file) on the raster image. Right click on the layer and Save as

2. A Save vector dialog box will pop up. Change Format to CSV and save in your working folder under places.csv. Make sure you uncheck Add saved file to map.



Snippet of the Building Repair survey csv table. We are bringing in details to the places.csv file.In excel,  copy out the attribute column and rows from the building repair survey table and paste into the places.csv sheet.


3. When you paste the places.csv will look like this. The pasted contents are to the right beginning from column C.

4. We will now return the places.csv table back to QGIS. Click on Create a layer from Delimited Text file and the dialog box will come up. Browse to where the places.csv file is and load it into QGIS.

5.       Put the proper coordinate reference system


6. You now have two identical spatial layers. Change the name of the new layer to placescsv so you don’t mix up the two. Remove the first layer –places.


7. To carry out the Selection by Attributes, we will need to build a query. Click on the Layer on the main menu, scroll down and select Query.


8. Our selection is “Building_col” = ‘blue’'. Double click on the field to be queried (Building_col), choose an operator (=) and take the value (blue) you are querying for. The message box gives the result.


9. Right Click on the layer- placescsv and open attribute table to view the rows selected from the Query.


Hope you enjoyed the post. Feel free to start practicing and send your comments.

Joining data between related attribute tables using Arcmap 10.2

In our previous post, we did this process using QGIS and we hope you have started practicing. From the feedback, some commentators requested for sample data to be able to also follow the processes.
We have provided sample data on our resources page so you can go there and download the files.

 Overview
Joining attribute data between related tables. Note that the two attribute tables should share a relationship with each other, there must be an identical field.  

Task 
  Our task today is to join the attributes from building repair survey table to the point feature-places on the map. We have two sets of data. Our point feature file on the map called places.shp and our building repair survey results on table in csv format. Note that ArcMap loads table data in csv and tab delimited text formats.

Procedure
1. Let us have a look at our data. The places layer is represented as red dots on the map while the building repair survey is a table. You can see them in the table of contents. 

2. Let us inspect the attribute tables we intend to join. Right Click the places layer>open attribute table. You will notice there is not much data to go by. Take note of the Id field.


3. Right click on the building repair table >open attribute table. You will notice it has a field called ID too. You will notice all the other data  taken during the survey.

  
4. To execute the join, right click on the places layer>Join and Relates>Join 




5. A Join Data dialog box will open up. Make sure you select the identical fields on both tables to base the Join on. 



6. To inspect the Join, Right click on places layer in the table of contents>open attribute table. Notice both tables are joined now. The original places attribute table is to the left.

Hope you are already practicing. Don’t forget to get your sample data from the resources page