Module 3: G.I.Systems and Data

During this weeks module we learned how to collect data out in the field and how to share that data. Also, we learned how different projections of a map can change how it will be seen in ArcGIS Pro.

ArcGIS Collector and Data Sharing

As an archaeologist I have been using ArcGIS online and Field Maps. This was important for my job because we could take our cell phones out in the field and collect the data we needed for our projects. Also, we could make the maps that were created on ArcGIS online to an off line status for times when we were in the field and did not have cell service but could still collect data. Finally when you are done collecting the data you can sync it with your account and update your online map.

When sharing the data there have been different ways I have given it to others and have received it from a client. Many people within the company can use the ArcGIS online account and we can share maps that way and make it easier for people in the field. Another way I have shared data was by making a Map Package. I usually did this when I was done with a map, but I needed to send it to another person who did not have all the data I had saved on my computer. The map package is easier because you can send the data to someone else and they can manipulate it on their end without messing up your original map. Lastly, when sharing data I would usually get a kmz/kml file from Google Earth that the client had created and put it into ArcGIS Pro. The only bad part about the Google Earth files is that you cannot manipulate it yourself (i.e. change the symbol or the color of the file). It makes it harder when the color is not what you need it to be for the client.

Being able to share data is important because you know exactly what the client needs to get the project done and you can work through many different avenues to get that done.

Projections

When getting data one does not always know what form the data is being projected. Many different entities use different projections. An example is how most people in navigation use State Plane. It does change sometimes from 1983 and 1983 HARN. It is important to know the difference because it can change where a feature gets projected on the map. As an archaeologist I mostly use Universal Transverse Meracator (UTM) because that is what most GPS systems have as a default. Also, since archaeologists work in meters it is easier to stay in the same projection. 

When making this weeks map we projected Albers Conical Equal Area, NAD 1983 UTM Zone 16N, and NAD 1983 to HARN Florida. Each one of the projections map the map slightly different. This could only be seen when making a map for each projection. Also, the module showed how each projection would change the area of the counties that were shown. The reason for this is that each projection is based off how it lines up with the equator. Another important aspect to know about imagery and raster data is being presented. The data will automatically end up in the Atlantic ocean until you are able to project into your projection. Once you do that the image with end up in the correct location. Sometimes when you don't know the projection you do have to play around with in until you find the right projection.

The map below represents four different counties (Alachua, Escambia, Miami-Dade, and Polk) in the the state of Florida and how each projection changes the location of the state slightly. Also, I learned how to get the colors to be the same across all the maps. Lastly, the map has a table that shows how each projection does change the area of the feature across the different projections.