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# System prepended metadata

title: Lab 3

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# Lab 3

`Contributer: An-Te Zhixin`



- Note that as I mention in the email, I won't reply your emails or messeges asking the first few steps in the lab on the due day in the future. Office hour is not for speed run of homework.


## Q1
- After you download the two images, set the coordinate system and projection of the two images, then make a screenshot for each of the images.
    - Make sure you show both projection and geographic coordinate system
Example:
![](https://i.imgur.com/7Tb0ToQ.jpg)
### Earth Explorer
- My recommendation is to define the range by map.
- Zhixin's method is:
![](https://i.imgur.com/2hJBBz8.png)

- **Make sure you select the same as this slide**
![](https://i.imgur.com/HLI6jsj.jpg)

### National map
- Go to https://apps.nationalmap.gov/downloader/#/
![](https://i.imgur.com/f46UA2w.png)



## Q2 
### Set Map projection
![](https://i.imgur.com/nV9WtLj.png)

### Set raster/vector projection
- Go to geoprocessing toolbox
- Search define projection
- Search Project raster for images
- Search Project for vectors


## Q3
![](https://i.imgur.com/zjGycww.png)
![](https://i.imgur.com/qmsdCta.png)

- You have to select an image before doing the measurements. To select the image, left click the image (layer) in "Content". Then you must do the measurements on the same image, or you get the error.
- You can show only one image at a time so that you won't click on the other images.

![](https://i.imgur.com/pPVaoDB.png)
