Map and Compass Honor

Recreational Activities

Requirements

  1. What are the cardinal and intercardinal points, their abbreviations, and corresponding degrees?

    Answer: Cardinal points: North (N, 0°/360°), East (E, 90°), South (S, 180°) and West (W, 270°). Intercardinal points: Northeast (NE, 45°), Southeast (SE, 135°), Southwest (SW, 225°) and Northwest (NW, 315°). — The 4 cardinal and the 4 intercardinal points, with their degrees, are the basis of compass orientation.

  2. What is a topographic map and what are its main uses?

    Answer: A topographic map is one that represents the relief and details of the Earth's surface, using contour lines to show altitudes and landforms, in addition to rivers, roads, vegetation and buildings. Uses: planning trails and expeditions, orienting oneself in the field, and supporting studies in engineering, agriculture, geography and land navigation. — The topographic map shows the relief through contour lines — essential for orienting oneself and planning in the field.

  3. Know and explain the following, in relation to the map:
    • What the Grid system is;
    • What the UTM grid is;
    • How many UTM zones do we have in the territory of the South American Division?
    • Identify which zone your city is in and how this zone is called (named);
    • Explain how to use a UTM coordinate system.

    Answer: 1) Grid system: it is a mesh of lines (grid squares) overlaid on the map that allows any point to be located by means of coordinates. 2) UTM grid (Universal Transverse Mercator): a system that divides the Earth into 60 zones of 6° of longitude each and provides coordinates in meters, which makes it more precise for field use. 3) UTM zones in the South American Division: the SAD territory spans several zones, approximately from zone 18 to 25 (about 8 zones). 4) Your city's zone: you should locate the city on the map and identify the corresponding zone number (much of Brazil lies between zones 22, 23 and 24); each zone is named by its number (e.g., "zone 23 South"). 5) How to use the UTM coordinate system: first read the E (East) coordinate and then the N (North) coordinate, both in meters, to locate the exact point within the grid square. — The UTM system divides the world into zones and gives coordinates in meters — precise and practical for land navigation.

  4. Know and explain the following, in relation to map reading:
    • Grid north;
    • True north;
    • Magnetic north;
    • Magnetic declination;
    • Meridian convergence.

    Answer: 1) Grid north: it is the "upward" direction indicated by the vertical lines of the map's grid. 2) True (geographic) north: points to the geographic North Pole, that is, the Earth's axis of rotation. 3) Magnetic north: it is the direction toward which the compass needle points, indicating the magnetic North Pole, which shifts slowly over time. 4) Magnetic declination: it is the angle of difference between true north and magnetic north at a given location. 5) Meridian convergence: it is the angle between true north and grid north. — There are three 'norths' (grid, true and magnetic); knowing the declination between them is what makes navigation precise.

  5. Know and explain the following with respect to topography:
    • Elevation;
    • Contour interval;
    • Landforms (valleys, ridges, cliffs, escarpments, hills, mountains, etc.) defined by contour lines.

    Answer: 1) Elevation: it is the altitude of a point measured relative to sea level. 2) Interval between contour lines (contour interval): it is the difference in altitude between one contour line and the next (for example, 20 m). 3) Landforms defined by contour lines: very close contours indicate steep terrain (cliffs and escarpments); widely spaced contours indicate gentle terrain; closed circles indicate a summit (hill or mountain); contours shaped like a "V" pointing toward the high ground indicate a valley (or watercourse), and a "V" pointing toward the low ground indicate a ridge or spur. — Reading the contour lines is 'seeing' the relief on paper: close together is steep, far apart is gentle.

  6. Know and explain the following with respect to distance:
    • How are distances determined?
    • The scale of the map;
    • How to measure linear distance;
    • How to convert to the actual distance.

    Answer: 1) How distances are defined: distances on the map are defined by the scale, which relates the measurement made on paper to the actual measurement on the terrain. 2) The map scale: it is the ratio between the measurement on the map and the actual measurement (e.g., 1:50,000 means that 1 cm on the map equals 50,000 cm = 500 m in reality). 3) How to measure linear distance: measure directly on the map with a ruler for straight stretches, or with a tape/string molded to the route for curved stretches, and then compare with the scale. 4) How to convert to actual distance: multiply the measurement obtained on the map by the denominator of the scale (e.g., 4 cm at 1:50,000 = 4 × 50,000 = 200,000 cm = 2 km). — The scale is the key: measure on the map and multiply by the denominator to get the actual distance on the terrain.

  7. Be able to identify at least 20 signs and symbols found on topographic maps. Some of them should be from the following categories:
    • Man-made structures;
    • Places with water;
    • Vegetation features.
  8. What is an orthophoto map?

    Answer: An orthophoto map (orthophotomap) is an aerial or satellite image corrected geometrically, so that the entire image is at the same scale and without distortions — allowing distances and areas to be measured directly on the photo, as on a map, but with the visual richness of a real photograph of the terrain. — The orthophoto is an aerial photo 'corrected' to become a map — it combines the realism of the image with measurement precision.

  9. Know the parts of a compass. Draw a Silva or cartographic compass and detail its tools and applications in the drawing.

    Answer: The parts of a cartographic compass (Silva type): the transparent base plate with ruler and scales; the direction-of-travel arrow (on the base); the rotating bezel (housing) graduated from 0° to 360°; the magnetic needle (the red tip points to magnetic north); the north-south orienting lines inside the housing; and the orienting arrow (north of the housing). (The drawing must show each of these parts.) — Knowing each part of the compass — base, bezel, needle and arrows — is what allows you to take and follow bearings with precision.

  10. Know and explain the following with respect to the compass, azimuth and coordinates:
    • What is azimuth?
    • How to calculate the coordinate from the map?
    • How to convert a geographic coordinate into a magnetic coordinate (azimuth)?
    • How to convert a magnetic coordinate (azimuth) into a geographic coordinate?
    • What is deviation and how to correct it?
    • How to calculate and follow a back azimuth?

    Answer: 1) What azimuth is: it is the angle measured from north, clockwise (from 0° to 360°), that indicates the direction of a point. 2) How to calculate a coordinate from the map: locate the point in the UTM grid square and read the E (East) and N (North) values in meters. 3) Convert a geographic coordinate into a magnetic one (azimuth): take the bearing (direction) on the map relative to true/grid north, and add or subtract the local magnetic declination to obtain the azimuth to be followed on the compass. 4) Convert a magnetic coordinate (azimuth) into a geographic one: do the reverse, starting from the azimuth read on the compass and correcting for the magnetic declination to obtain the corresponding bearing on the map. 5) What deviation is and how to correct it: deviation is the difference between magnetic north and true north (the magnetic declination); it is corrected by adding or subtracting the value of the local declination, depending on whether it is east or west. 6) How to calculate and follow a back azimuth: the back azimuth is the direction opposite to the azimuth (azimuth ± 180°: add 180° if the value is less than 180°, or subtract 180° if it is greater); it is used to return along the same path or to check the bearing followed. — The azimuth is the direction in degrees from north; correcting the declination and calculating the back azimuth is what ensures you get there and back.

  11. Explain how to orient yourself using your map by:
    • Visual inspection;
    • Using a compass.

    Answer: 1) Visual inspection: hold the map horizontally and turn it until the features drawn on the paper (roads, rivers, mountain ridges, bridges) line up with the same real features around you. Use reference points visible on the terrain to confirm that the map is aligned with what you see; that way the north of the paper points to real north and you know where you are. 2) Using a compass: place the map on a flat surface, position the compass on it, and turn the map and compass together until the north of the map is aligned with the magnetic north indicated by the needle, correcting for the region's magnetic declination. With the map oriented, measure the azimuth (bearing) from your point to the destination and follow that azimuth on the terrain to reach the desired location. — To orient is to align the map with the real world — by reference points (visual) or by the compass's north.

  12. Follow a course using a map and compass with at least 10 readings or control points.