Terms : Hide Images
| 13111214521 | GIS stands for | Geographic Information System | 0 | |
| 13111217677 | Who/what uses GIS? | Conservation groups construction companies city infrastructure military GPS Fema Insurance companies | 1 | |
| 13111222016 | Uses of GIS | Mapping monitoring managing data | 2 | |
| 13111225212 | GIS can measure | length, area and 3D features | 3 | |
| 13111229297 | What is GIS? | GIS is a computer based system that aids in the collection, analysis, output, management of spatial data and information | 4 | |
| 13111237240 | GIS can represent | the world digitally | 5 | |
| 13111240856 | 2 Data models are | raster and vector | 6 | |
| 13111243205 | Vector: | Sees the world as an entity or object Used when anything is easily separated or discrete ex: buildings | 7 | |
| 13111249179 | Rasters: | sees the world as a field Is continuous Ex: landscapes, temperature | 8 | |
| 13111259600 | Vector Data models are represented by | geometric representations such as points, lines and polygons | 9 | |
| 13111265481 | T or F: geometric representations can change with scale? | True | 10 | |
| 13111269044 | Explain what rasters do | Use a matrix of rows by columns. each cell pixel is a square and in each cell is a stored number. | 11 | |
| 13111288608 | Extent is | rows x columns | 12 | |
| 13111290365 | Digital pictures are represented by what kind of model? | rasters | 13 | |
| 13111292594 | cell size is | length x width of single cell | 14 | |
| 13111302531 | Advantages/ disadvantages of rasters | Data structure is simple Storage is less efficient for small files, but more efficient for large files Rasters much more superior for analysis. numbers are easier to manipulate | 15 | |
| 13111318079 | Advantages/ disadvantages of Vectors | Data structures are much more complicated, uses boolean logic and stores nodes and lines. Much more efficient for small files | 16 | |
| 13111334963 | Digitizing: | Process of converting geography data from a map or image into a digital format by tracing its feature. Used for vectors | 17 | |
| 13111342569 | Ways to digitize? | Manual map digitization On screen digitization | 18 | |
| 13111346399 | manual vs. heads up | manual -can be better for physical map analysis -more work -more complicated with lots of clean up -large maps Heads up -easier -more common -cheaper -needs scanned map | 19 | |
| 13111356203 | Nodes vs vertices: | Nodes are points on the endpoints of lines Vertices are points on a line that aren't at the beginning or the end. | 20 | |
| 13111361761 | Digitizing errors are; | Under/overshooting -when nodes don't quite reach line (undershoot) -when lines cross over existing nodes/lines Dangling node polygon label point missing label point pseudonode line crossing with no node (**Always use snap tool to prevent this) | 21 | |
| 13111379999 | T or F: 1/16000 > 1/19000000 | True | 22 | |
| 13111400657 | Connectivity: | arcs/lines are connected to others at nodes | 23 | |
| 13111404095 | Containment | An enclosed polygon has a measurable area; lists of arcs define boundaries and closed areas | 24 | |
| 13111411115 | Contiguity | the adjacency of polygons can be determined by shared arcs can be between features of the same class or different classes | 25 | |
| 13111423651 | Rows in an attribute table are called | records | 26 | |
| 13111423652 | Data types | Nominal attributes text ordinal cardinal dates ratio | 27 | |
| 13111430577 | Nominal attributes are used for | idenitification | 28 | |
| 13111434007 | Text attributes are for | characters/ numbers? | 29 | |
| 13111436083 | Ordinal attributes are for | Quartile analysis stores as bytes and integers | 30 | |
| 13111441779 | Cardinal attributes are used for | temperature. You can add and subtract, but not multiply or divide | 31 | |
| 13111446487 | Date attributes are used for | adding and subtracting dates | 32 | |
| 13111448337 | Ratio attributes are good for | crop yield, area, density (stores as integer, float, double) | 33 | |
| 13111453235 | rank by size (float, double, integer) | integer| 34 | | |
| 13111456036 | Precision in GIS refers to | number of numbers ex: 160,000 in a stadium has a precision of 6, so if highest number can be 999,999. | 35 | |
| 13111462921 | Scale= | number of decimal places Ex: 432.1324 scale = 4 | 36 | |
| 13111474825 | Are there specific coordinates for a certain location? if to why? | no, locations have multiple coordinates because we use different models with different coordinate systems | 37 | |
| 13111481098 | Why do we have different coordinate systems? | technology earth is a geoid -irregular ellipsoid -differences in gravitational forces -bulges and dips ***NOT about topography | 38 | |
| 13111524002 | Two major groups of coordinate systems are: | Geographic and projected | 39 | |
| 13111526954 | Geographic Coordinate Systems | Latitude/longitude Decimal degrees Horizontal units = DMS outside GIS | 40 | |
| 13111536795 | How do you convert DMS to DD? | DMS=30º 16' 0.9336" DD= D +m/60 +s/3600 DD= 30+0.266+2.59e-4 DD=30.266 ***NOTE if this is in the south, make degree Negative | 41 | |
| 13111589623 | When defining a geographic coordinate system you need to | Specify datum | 42 | |
| 13111594624 | Datum is the | main reference point of known coordinates Size of earth | 43 | |
| 13111602496 | What are the known locations by convention | Greenwich meridian Equator | 44 | |
| 13111605424 | What is an issue with DD? | It isn't constant as you move N or S | 45 | |
| 13111612153 | Projected Coordinate Systems | flatten Earth (3D-2D) Change units of measurement to m, ft May change origin Distortion | 46 | |
| 13111619214 | Projection vs. Coordinate System | Geographic CS -horizontal datum=DD -origin is (0,0) -Datum is the size of earth model - uses survey points -Difficult to do simple math (distance, areas, perimeter) Projected CS: -3D-2D -Horizontal units are m, ft -Uses Cartesian System -Might change origin | 47 | |
| 13111643619 | When converting 3D-2D it is impossible to do so without | distortion | 48 | |
| 13111643620 | Types of distoriton | shape distance area azimuth (direction) | 49 | |
| 13111647602 | Equal area projections | attempt to maintain the relative spatial science and the areas on the map, however these can distort the actual shape of polygons, such as the Lambert projections bending and squishing the northern Canadian islands to keep them at the same map scale as southern Canada on a flat sheet of paper | 50 | |
| 13111651993 | Conformal Projections | attempt to maintain the shape of polygons on the map, the downside is that conformal projections can distort the relative area from one part of the map to the other, for instance, in the commonly used Mercator projection, the shape of Greenland is preserved, but it appears to be much larger in size than it actually is | 51 | |
| 13111692019 | equidistant projection | map that maintains distance but distorts other properties | 52 | |
| 13111697300 | Azimuthal Projection | A map projection that shows true directions from a single point, creating a 'realistic' view of earth as seen from space. | 53 | |
| 13111711252 | Developable surfaces include | cylinder (area is distorted) cone planar (3D objects that can be transformed into a 2D object without distortion) | 54 | |
| 13111718965 | Cylinders are good for | distance and direction | 55 | |
| 13111721138 | Planar is good when | mapping polar areas | 56 | |
| 13111724145 | Equal Earth projection | maintains area | 57 | |
| 13111729950 | When choosing projections, think about: | geometric property to maintain Extent size of area (smaller areas have more flexibility) units (m,ft) | 58 | |
| 13111739497 | UTM Projection | -Composed of 60 zones that are divided by N/S. Each zone is a secant cyclindrical (Mercator) projection, with standard lines approx. 180km to each side of the central meridian. -each zone is about 6º wide -center is (0,500,000m) EX: 622,791 is east of center EX: 334,266 is meters north of equator | 59 | |
| 13111839188 | What do you need to find specific location in UTM? | zone, S,N, coordinates | 60 | |
| 13111843618 | When do you want to use UTM? | When the extent falls within 1 zone. For example, use for bear county, but not for entire state of texas. | 61 | |
| 13111855527 | What projection is good for USA? | Albers Equal Area | 62 | |
| 13111870595 | When projecting rasters you need to | use resampling techniques know output cell size 1" ~ 30m | 63 | |
| 13111876379 | Resampling techniques | Nearest Neighbor Bilinear Cubic Major coarsening | 64 | |
| 13111898486 | Nearest Neighbor | a resampling method that uses the nearest pixel value to estimate a new pixel value -Chooses point that is closes to center in each cell | 65 | |
| 13111904003 | bilinear interpolation | calculates value for each output pixel based on a weighted average of the four nearest input pixels -Use for continuous data such as temp, elevation,windspeed | 66 | |
| 13111908674 | cubic interpolation | Uses 16 nearest neighbors, polynomial, predicts interpolated value | 67 | |
| 13111915673 | Majority coarsening the resolution | nominal attribute? | 68 | |
| 13111919821 | Query | to query is to find subset of original data that matches a logical statement | 69 | |
| 13111992100 | Look in notes and practice boolean examples | IF,AND,OR | 70 | |
| 13112010744 | chloropleth mapping groupings | equal interval Quantile classification Standard Deviation | 71 | |
| 13112024670 | Equal interval | a data classification method that selects class break levels by taking the total span of values (from highest to lowest) and dividing by the number of desired classes (highest-lowest)/5 | 72 | |
| 13112033726 | Quartile Classification | # in class = total observations/# classes | 73 | |
| 13112043803 | Percentile | A point on a ranking scale of 0 to 100. The 50th percentile is the midpoint; half the people in the population being studied rank higher and half rank lower. | 74 | |
| 13112045577 | Standard Deviation | a computed measure of how much scores vary around the mean score **Understand how to compute | 75 | |
| 13112055885 | Standard deviation is good when looking for | outliers way below or above average. Can use to look at gaussian distribution and understand if data is symmetric or not | 76 | |
| 13112063171 | If a table displays -9999 this means | The value is unknown and should be excluded | 77 | |
| 13112065713 | Natural breaks | a data classification scheme that divides values based on natural groupings or gaps between values -Intervals will be created such that the variation within each group is the smallest possible | 78 | |
| 13112074321 | Chloropleth mapping is good for | spatially intensive data data thats averaged or normalized ratios **DONT use extensive attributes | 79 | |
| 13112095906 | Chloropleth is best used for | skewed distributions uniform (*check histogram) | 80 | |
| 13112104763 | Modifiable Areal Unit Problem (MAUP) | Problem associated with aggregate data sources Use of Arbitrary spatial units Problem of Scale - Scale effect: spatial data analysis at different scales may produce different results - Zonal effect: regrouping zones at a given scale may produce different results -used for gerrymandering | 81 | |
| 13112120922 | Three main elements for map lyout | Focus, Order, Contrast arrange by Map->title->others | 82 | |
| 13112207501 | How to project? | Search 'project' -> know what you want as output->output dataset (search CS) ->ok-> open new arc map | 83 | |
| 13112222810 | State Plane CS | -follows political boundaries -organized by states and counties -False origin to measure in ft/m (zones) -best used east->west | 84 | |
| 13112246472 | Lambert Conformal | preserves shape W->E | 85 | |
| 13112254615 | Transverse Mercator | A projected coordinate system used for north-south data | 86 | |
| 13112261975 | spatial reference | the use of a real-world coordinate system for identifying locations | 87 | |
| 13112267413 | **If CS is not defined, | then search define projection | 88 | |
| 13112274619 | NEVER file a particular | CS, project file to a different CS | 89 | |
| 13112320916 | Define CS->original file project-> create new file on CS | idk what this means | 90 | |
| 13112365329 | Why are there different datums? | our realizations or estimates of the datum change as new points are added and survey methods improve. The datum is periodically updated as new or better measurements are made. | 91 | |
| 13112382656 | HARN and subsequent NAD83 adjustments are largely | satellite based and mark transition from physical and optical surveying to GPS/GNSS surveying. | 92 | |
| 13112392167 | Different Datums Specify | different CS and the version of the datum is important. | 93 | |
| 13112490205 | a map projection is | a systemic rendering of locations from the curved earth surface onto a flat map | 94 | |
| 13112513527 | How many norths are there any why | 3 Grid north-the direction of the y axis in a map projection Magnetic north-location a compass points Geographic north- pole around which globe resolves. | 95 | |
| 13112537265 | Distortion increases | away from the line of true scale | 96 | |
| 13112561261 | Lambert conformal conic | may be conceptualized as a cone intersecting the surface of the earth with points on the earths surface projected onto a cone. | 97 | |
| 13112602405 | for Lambert Conformal Conic, the distortion is smallest | near standard parallels (lines of intersection between cone and ellipsoid) and distortion increases as you move farther away from parallels. Has lower distortion in east-west direction hence why it is typically used for areas larger in east-west direction than N-S. (USA) | 98 | |
| 13112656459 | Transverse Map Projection may be conceptualized as enveloping | the earth in a horizontal cylinder and projecting earths surface onto cylinder. The cylinder intersects earth's ellipsoid along a single north-south tangent, or along two secant lines. -A line parallel to and midway between secants is the central meridian. -low distortion in north-south direction and distortion is smallest near the lines of intersection. -Distortion increases east to west. | 99 | |
| 13112729114 | State Plane coordinate system | specifies positions in cartesian coordinate systems for each state. -one or more zones for each state. -used for property surveys, large scale construction projects. | 100 | |
| 13112750822 | State Plane Coordinate system is based on | lambert conformal conic - used for states/zones with long east-west axes (north carolina, virginia) - used in 31 states. transverse mercator projections. - this is most often used with states or zones with long north-south axes (illinois, california) -used in 22 states -florida uses both transverse and lambert. | 101 | |
| 13112851072 | UTM coordinate systems are defined so that all coordinates are | positive within the zone -zone eastings have value >500,000m -so origin is 500,000 m west of central meridian. -all zones less than 1,000,000 m wide. | 102 | |
| 13113017092 | Mercator, Goode, Mollweide, and miller projections are used for | global projections -these are good for visualization, but not analysis | 103 | |
| 13113021728 | Distortion in world maps is reduced by | using a cut or interrupted surface. | 104 | |
| 13113055301 | PLSS | A coordinate that indicates a specific place using quarters, sections, townships, and ranges. *NOT a CS | 105 | |
| 13113140815 | Neatline | a line used to enclose one or more map elements in a rectangle | 106 | |
| 13113181668 | graticule | a network of lines representing meridians and parallels, on which a map or plan can be represented | 107 | |
| 13113195769 | Chloropleth maps depict | quantitative information for areas(population density) | 108 | |
| 13113201775 | Dot density maps | are commonly used to show quantitative data | 109 | |
| 13113214025 | isopleth maps | maps that have lines that connect equal points (isotherms/isobars/etc.) -used for contours | 110 | |
| 13113224972 | Large scale vs. small scale maps | Large scale refers to larger ration (1/24,000) (larger features, cover smaller area) ex: zoomed in on japan Small scale refers to smaller ratio (1/100,000)(smaller features, cover larger area) ex: this would be of asia. | 111 | |
| 13113251577 | Feature generalization | Modification of features when representing them on a map. | 112 | |
| 13113255846 | feature generalization examples | truth fused (combine polygons) Simplified (polygon detail simplified) Displaced (object moved) Omitted (small polygons could be omitted) Exaggerated(make symbol larger) | 113 | |
| 13113505798 | Metadata | information about the spatial data such as CS, content, source, lineage, extent etc | 114 | |
| 13113522087 | Domain | acceptable values an item may take ex: integer may be between 0 and 10 | 115 | |
| 13113586182 | When joining tables, | a single column in one table is matched to a column in another table and a new table is created by combining rows for matched values. | 116 | |
| 13113628131 | one-to-one relationship join | there may be one and only one instance in a join item of a source table that matches one and only one instance of a join item in a target table. | 117 |
