- Review - Maps & Photos
- the MATH
- unit conversions
- imperial (provided)
- 1 inch = 2.54cm
- 1m = 3.28 ft
- 1 mile = 63,360 in = 5,280ft
- metric (you should know)
- 1 m = 100 cm = 1,000 mm
- 1 km = 1,000 m
- 1 ha = 10,000 sq m
- dash = dash
- Scale
- map scale
- map / RW
- photo scale
- photo / RW
- f / H
- Interpolation
- coordinate
- short / long
- spot ht. - contour
- short / long
- Area
- dot grid / graph paper ... squares
- 1) size of square in RW units
- 2) number of squares (2 counts better than one)
- partial squares or borderline dots ... = 1/2
- triangles
-
- SOH CAH TOA ... ratios
- 3 diff ratios for the same angle
- = top as "%" of bottom
- angle can also be in DEGREES
- ratio ↔ degrees
- degrees → ratio ... Tan ... (e.g. Tan(45) = 1 )
- ratio → degrees ... ArcTan ... (e.g. ArcTan(1) = 45 )
- clino % is Tan
- LATs & DEPs
- Dep (Easting) = Sin(brg) * HD
- Lat (Northing) = Cos(brg) * HD
- brg from UTM
- ratio of interest = opp / adj
- ArcTan (opp/adj) = degrees
- add/subtract with reference cardinal brg
- Pythagoras
- a^2 + b^2 = c^2
- grade line
- grade % = contour interval
- (also a dash = dash)
-
- misc.
- A = E + H
- hill profile
- "straight down", measure, mark edge of paper
- DD MM SS ↔ DD.DDD
- DD MM SS → decimal
- MM / 60 + SS / 3600
- 49 25' 44" as DD.DDD
- 25 / 60 + 44 / 3600
- 0.417 + 0.012
- 49.429
- decimal → DD MM SS
- decimal * 60 = MM, left over decimal * 60 = SS
- 49.429 as DD MM SS
- 0.429 * 60 = 25.74 ... 25'
- 0.74 * 60 = 44.4"
- 49 25' 44"
- the CONCEPTS
- Map Basics
- Uses of maps
- Map components
- Types of maps
- media: mental, paper, digital (virtual)
- general reference (planimetric, topographic)
- thematic (inventory, soils, elections)
- Mapping Systems
-
- select / omit
- simplify
- aggregate
- displace
- exaggerate
- smooth
- Georeferencing
- unique description for location on Earth's surface
- Non-Metric (no measure)
- nominal or ordinal
- landmarks, place names
- street address
- issues
- "local"
- repeats
- inadequate for natural landscape
- Metric (measured)
- lat/long ... specify E/ W & N/ S
- datums
- UTM ... specify zone & N or S
- 60 zones @ 6 degrees
- Northing: equator = 0m
- Easting: central meridian = 500,000m (for each zone)
- Map Projections
- Distortion: shape, area, distance, direction
- developable surface: plane, cylinder, cone
- tangent vs. secant
- standard lines
- Mercator, UTM, BC Albers Equal Area
- Terrain
- vertical datum
- methods
- layer tinting (bands of colour)
- hill shading
- hachures
- hill profiles
- spot hts
- contours
- GPS
- How it works
- 24 SV's in high orbit
- each sends a unique signal signal (pseudorandom code)
- time diff. gives distance (speed of light)
- 1 SV = sphere ...
- 3 segments
- Error/ uncertainty
- clock
- ephemeris
- ionosphere & troposphere
- multi-path
- reciever
- PDOP (spacing & mask)
- selective availability
- differential correction
- Remote Sensing
- EMR
- wave energy: gamma ... visible ... radio
- 4 interactions
- atmos. window
- air photos
- activities
- photo interp
- photogrammetry
- orienteering
- stereoscopy
- use binocular vision
- view overlapping photos
- form a 3D image
- need
- stereo pair
- properly aligned
- stereoscope
- photos
- photo number
- flight line
- endlap, side lap
- drift, crab
- issues
- scale varies with elevation
- tops of objects are displaced ... hill tops are displaced
- orthophoto
- Satellite
- path of EMR = interactions along the way
- bands
- composites
- normal & false
- spectral signature
- LiDAR
- active ... "Li" = light
- point cloud
- DSM vs. DEM
