Lab 8

Working with ArcMap to manipulate and work with IMG files taking a basemap and overlaying and image file.

To sattelite image and overlayed it on the basemap and accentuated a portion of them map by using image analysis toolbar. Tools: DRA (exentuate the part of the map I wanted to focus, and clip to take out the piece I wanted then overlaying that on the original. Shown is how to export the clip into a raster file since the clip is not saved just heald in the clipboard. (**important** clips need to be exported this way so they are not lost)

ISODATA cluster unsupervised classification
>spatial analysis tool>multivariate>ISODATA cluster unsupervised classification
made multiple with 16/17(originaly 20 but would only allow 17)/8 to see how each one limits

ISOCLUSTER 1: 16

ISOCLUSTER 2: 17

ISOCLUSTER 3: 8

Each version allowing designated # of categories to the data though lower numbers would not allow for much manipulation later on so if I got farther through my work at need more categories to display would have to start over so planning is important.

Reclassify allowed me to take similiar attributes and combine them results before and after below

Played with display so that I could see the base map underneath changed to a transperancy of 60%

The program manipulated to color but that was maintained in the legend, was not sure how it was done in the lab slides but I think this would be close.

NDVI

Final with addition of data collected during the fieldtrip setup in layout view and added north arrow, legend, scale, and title. 

lab 7 Working Rasters

Rasters:

Extensions: Spatial Analysis (added toolbar for easy access)
Introduced Raster calculator (Spatial Analyst Tools>Map Algebra>Raster Calculator

Raster Calculator>environments>Processing extent/Raster Analysis: allow to select area that the calculator will focus.

Selected the Dem 30 which after the Calculator was converted into rastercal 1 (see below)

Wanted to add in road data (UWroad_clip) and used selection tool to select "Type_L"=  'Rd' and "Type_L" = "Blvd" then used analysis Tools>overlay>intersect with Studyarea similar to lab6 for practice and to follow closer to the clips in the power point

Selection shows designated area selected by the view of the window

Next selection >Raster calc>enviroments>raster analysis allowing to select a specific feature, was not sure of the selection that it made. Did not quite remeber this from class and without more information created a selection but not sure how it differed. Played around with it setting the Maximum inputs with the mask of layer 3. Selection the same as seen above. though I am not quite sure how to interpret the difference. 

>spatial analysis>surface>hillshade: input raster rastercalc5 created above with stretched symbology overlayed over the intersect clip created earlier. 

Took selection and converted into an ASPECT (>spacial analysis tools>surface>Aspect) input raster the hillshade created earlier. 

Using the raster calculator and sin("aspect_hills1" * 3.1459/180) using basic numerical functions. (note: resuls look much like the hillshade effect 

Results gave a depth to the map though i honestly do not understand all the conversions just need more time working with them. Basic understanding is useful though. I understand though it is useful for highlighting and area and bringing and individuals attention to an important area but leaving surrounding information available for reference. 

Lab 3

The lab was on overview of ArcGIS introduction to the tools associated with creating spatial maps and managing data associated with it. 

Our main focuses
ArcToolbox- Tools to work with spatial data
ArcMap- Viewing, manipulating, and quantifying spatial data
ArcCatalog- Organizing spatial data.

ArcGIS Geodatabase: "At its most basic level, the geodatabase is a container for storing spatial and attribute data and the relationships that exist among them. Geodatabases are created, edited, and managed using the standard menus and tools in ArcCatalog™ and ArcMap™." 
(Note: not widely used in the sciences though Miles notes that one day it will be due to it's efficiency The slides give a lot of information surrounding the database but it will not be covered much in the class)

Geographic data (2d, 3d)
Spatial: Location, shape, relating features (Layers: Vectors, Rasters, surface, images)
Descriptive data: defining attributes and characteristics of spatial features. 

Lab 2

Lab 2 was an overview of spatial elements
( Most information and pictures taken directly from lecture slides (lecture 2 SPIT 2015) 

Points- a point has no area but is a fixed position (coordinates)
Lines- a connection between 2 or more points
Area- the space enclosed by multiple points and lines. 

Raster (see picture) 

The numbers represent a spatial value no matter how small your "pixel" is never an exact representation of actual geography

Vector (see picture)

Represented by coordinate data taken by GPS measurements x, y coordinates

GPS section- An overview of the history of gps and it's limitations


Why use GPS
(1)
•Availability:
–1995, DoD NAVSTAR, civilian use foreseeable future
•Accuracy: Factors
–work with “primary” data sources
–High inherent accuracy (2.5m medium-quality properly corrected receiver)
–Time Corrected to 1/1 billionth of a second

Differential GPS:  An extension of the GPS system that uses land-based radio beacons to transmit position corrections to GPS receivers. DGPS reduces the effect of selective availability, propagation delay, etc. and can improve position accuracy to better than 10 meters.of a second (notes) I understand this is mainly used for marine navigation I am not sure if it is useful for land based mesurements. Possibly for air. 

Sources of error

Satellite clock errors  < 1 meter

Ephemeris errors   (satellite position)  < 1 meter

Receiver errors  < 2 meters

Ionosphere errors (upper atmos.)  < 2 meters

Troposphere errors (lower atmos.)  < 2 meters

Most of these seem to be out of the users control though need to be taken into account when anomolies are found within the data. 

Multipath errors (bounced signals)  ???- seems to be the most controllable, being able to recognize areas that could potentially reflect signals causing error within how your receiver interprets them. I believe this was similar to what we were going over in the example when were taking data. The instructors had us take reading next to the building which would likely reflect the signals manipulating our data of the "square" 

Considered the most accurate representation of space with the least amount of error. (note: the distortion at the poles. The farther you get away from the equator the more distortion of information. 

Remote Sensing/Landsat 

Representing the reflection of solar radiation off the earth with satellite instruments. Multiple satellites all with different capabilities that cover different wavelengths of light. Important to note that what we see is what is not absorbed by the surface example (we see green when we look at plants due to the absorption of other light waves) Important to pay attention to the wavelengths that are covered and how often the satellite can pass over the area that you want. often takes multiple passes due to possible cloud coverage. 

landsat-etm has a 30m resolution and repeats every 16 days. 

First launch in 1972

•Landsat 1 – 7, today 5 TM and 7 ETM+ still fly

–15m, 30m, & 60m pixel resolution

–7 spectral bands, 1 panchromatic band

•3 Visible, 2 NIR, 1 MIR, 1 Thermal Low/High Gain

–Every 16 days

–Tuned for looking at the land

–Broad spectral bands

–Can “see” into estuaries and rivers