Editing SAR Fundamentals/Navigation instruments theory

From PCSAR

Jump to: navigation, search

Warning: You are not logged in. Your IP address will be recorded in this page's edit history.

The edit can be undone. Please check the comparison below to verify that this is what you want to do, and then save the changes below to finish undoing the edit.

Current revision Your text
Line 15: Line 15:
For each instrument, the theory of how it operates is discussed
For each instrument, the theory of how it operates is discussed
along with how to select an instrument for purchase.
along with how to select an instrument for purchase.
 +
 +
Only basic use of a GPS is shown. Advanced features such as waypoints,
 +
tracks and maps are left to another lesson beyond the SAR Fundamentals course.
== Authors ==
== Authors ==
Line 25: Line 28:
: Basic SAR Skills Manual: Ch.7 "Navigation"
: Basic SAR Skills Manual: Ch.7 "Navigation"
: stride count
: stride count
-
 
-
Only basic use of a GPS is shown. Advanced features such as waypoints,
 
-
tracks and maps are left to another lesson beyond the SAR Fundamentals course.
 
-
* Waypoints are not an essential skill for using GPS. Students should be recording locations on paper, and should be able to estimate relative direction and distance to a new location.
 
-
** This material can be covered in additional material presented by a SAR group outside the SAR Fundamentals course.
 
== Prerequisites ==
== Prerequisites ==
Line 54: Line 52:
== Objectives ==
== Objectives ==
-
At the conclusion of this lesson the participants will be able to:
+
At the conclusion of this lesson the participants:
-
# explain how a GPS works
+
# will be able to ...
-
# identify purposes for which a GPS is sufficient, a help, not useful
+
-
# identify circumstances under which a GPS may fail
+
-
# identify the significant configuration options of most GPS models
+
-
# identify when to use NAD27 vs. NAD83/WGS84
+
-
# configure a particular model of GPS for local SAR usage
+
-
# read a UTM off a particular model of GPS and translate that to and from the UTM notation used with topographic maps.
+
-
# determine the UTM of the location where they are at and the accuracy of their reading
+
-
# given a destination UTM know what direction and distance to go to get to it
+
-
# select a GPS for purchase
+
-
# identify the parts of a compass
+
-
# explain how a compass works
+
-
# select a compass for purchase
+
== Time Plan ==
== Time Plan ==
-
Total Time: 1 hour 45 minutes
+
Total Time: 90 minutes
-
* 2013-02: 1 hour 16 min
+
-
 
+
-
See:
+
-
* {{link|Image:Members:2016-10-26 21 44 40u-scan.pdf}}
+
-
* {{link|Image:Members:2016-10-26 21 49 28u-scan0014.pdf}}
+
{{lesson slides start}}
{{lesson slides start}}
{{lesson slide|00:00|3 min}}
{{lesson slide|00:00|3 min}}
-
'''Introduction'''
 
-
 
Introduce topic title
Introduce topic title
Line 86: Line 65:
Present Objectives
Present Objectives
-
 
+
{{lesson slide|00:03|}}
-
Determine experience level of students.
+
-
* Who uses GPS regularly?
+
-
* Who uses a compass regularly?
+
-
* Who is comfortable reading UTM's off a map?
+
-
* Recruit more advanced students to assist in illustrating material.
+
-
 
+
-
{{lesson slide|00:03|1 min}}
+
'''Instruments'''
'''Instruments'''
Line 102: Line 74:
The four instruments we will discuss:
The four instruments we will discuss:
-
* pace counter
 
* compass
* compass
-
* altimeter
 
* GPS
* GPS
 +
* altimeter
 +
* pace counter
No one instrument is perfect. Each is better in some circumstances.
No one instrument is perfect. Each is better in some circumstances.
-
Each instrument has different ways of failing.
+
Each instrument has a different way of failing.
-
{{lesson slide|00:04|2 min}}
+
{{lesson slide||}}
-
'''Pace Counter'''
+
-
Measuring distance with your feet.
+
'''Compass'''
-
When a GPS isn't working this is the best that can be done in the field.
+
So far having been using the compass on the map.
-
Will be practiced in a separate exercise.
+
Can also be used in the field.
 +
Because of magnetic needle.
-
Pace is landing with the same foot.
 
-
Need to count each pace.
+
{{lesson slide||}}
 +
'''Magnetic North, Declination'''
-
beads - slide bead on every 10 paces. Slide other for every 100 paces.
+
The needle of the compass points in the direction of Magnetic North.
-
pedometer - measures the jiggle from each pace.
+
This is not the same as True North.
-
alternatives:
+
The difference between True North and Magnetic North is called
-
* count in your head
+
Declination.
-
* use note book.
+
-
* less accurate: know your speed and measure your time.
+
-
{{lesson slide|00:06|1 min}}
+
It's expressed in degrees and fractions of degrees (minutes).
-
'''Compass'''
+
-
So far having been using the compass on the map.
+
If Magnetic North is to the west of True North, the declination is
 +
degrees WEST. Opposite is degrees EAST.
-
Can also be used in the field.
 
-
Because of magnetic needle.
 
 +
{{lesson slide||}}
 +
'''What direction is Magnetic North?'''
-
{{lesson slide|00:07|2 min}}
+
Magnetic North points in the direct of Earth's North Magnetic Pole.
-
'''Magnetic North'''
+
-
The needle of the compass points in the direction of Magnetic North
+
It's also somewhat altered by regional geomagnetic features.
-
towards the North Magnetic Pole.
+
-
This is not the same as True North.
 
The North Magnetic Pole isn't the same location as the north pole.
The North Magnetic Pole isn't the same location as the north pole.
-
North Magnetic Pole is currently (2019) 8634 deg N 175.3 deg E
+
North Magnetic Pole is currently (2012) 85.9 deg N 147.0 deg W
-
northwest of of the tip of Ellsmere Island, now in Russia Arctic.
+
northwest of of the tip of Ellsmere Island.
It moves. About 55 km closer to Russia each year.
It moves. About 55 km closer to Russia each year.
-
{{lesson slide|00:09|4 min}}
+
{{lesson slide||}}
-
'''Declination'''
+
'''Finding declination'''
-
The difference between True North and Magnetic North is called
+
Declination changes from year to year.
-
Declination.
+
-
It's expressed in degrees and fractions of degrees (minutes).
+
It also changes from area to area.
-
If Magnetic North is to the east of True North, the declination is
+
Because North Pole and the North Magnetic Pole appear further apart or
-
degrees EAST. Opposite is degrees WEST.
+
closer together depending on where you are located.
-
Declination changes from year to year.
+
In our area, declination increases:
-
 
+
* the further west you go
-
It also changes from area to area.
+
* or the further north you go
* Pincher Creek has about half a degree more declination than Lethbridge.
* Pincher Creek has about half a degree more declination than Lethbridge.
Line 175: Line 141:
{{quote-page|Navigation/Declinations}}
{{quote-page|Navigation/Declinations}}
-
Look up online [[Navigation#Declination|Declination]]: http://magnetic-declination.com/
+
Look up online [[Navigation#Declination|Declination]]: http://geomag.nrcan.gc.ca/apps/mdcal-eng.php
Calculation on topo maps is old, not accurate.
Calculation on topo maps is old, not accurate.
Line 181: Line 147:
Ask the person briefing you.
Ask the person briefing you.
-
{{lesson slide|00:13|4 min}}
+
{{lesson slide||}}
'''Compass failures'''
'''Compass failures'''
Line 192: Line 158:
** generators, electric motors
** generators, electric motors
-
attracted to certain metals
+
attracted to certain metals (iron, nickel, cobalt, alloys like steel)
* don't hold close to building, vehicle, belt buckle
* don't hold close to building, vehicle, belt buckle
Line 205: Line 171:
* unless compass has "Global" needle bearings
* unless compass has "Global" needle bearings
-
{{lesson slide|00:17|7 min}}
+
{{lesson slide||}}
'''Choosing a compass'''
'''Choosing a compass'''
Line 211: Line 177:
* straight edge
* straight edge
* ruler (scale)
* ruler (scale)
-
* roamer
 
* bezel (barrel) in 360 degrees (not 4 x 90 degrees, mils, or named directions)
* bezel (barrel) in 360 degrees (not 4 x 90 degrees, mils, or named directions)
-
* interior north-south lines
+
* roamer
-
* adjustable declination
+
* nice: magnefying lens
-
* nice: magnifying lens
+
* sighting mirror
* sighting mirror
** sighting line
** sighting line
** sighting notch
** sighting notch
*** nice: both top and bottom of mirror
*** nice: both top and bottom of mirror
 +
* setable declination
* needle zones (nice: Global)
* needle zones (nice: Global)
* nice: luminous
* nice: luminous
Line 229: Line 194:
* approx $70
* approx $70
-
{{lesson slide|00:24|4 min}}
+
{{lesson slide||}}
-
'''Altimeter'''
+
'''GPS'''
-
Measures the weight of the air above you - air pressure.
+
* GPS component covers up to 1:13 of the attached lesson plan
 +
** Waypoints are not an essential skill for using GPS. Students should be recording locations on paper, and should be able to estimate relative direction and distance to a new location.
 +
*** This material can be covered in additional material presented by a SAR group outside the SAR Fundamentals course.
-
The higher you go up, the less pressure - displays elevation is feet or meters.
+
[[Image:GPS-lesson-plan.odt|GPS lesson plan (odt)]]
 +
([[:Image:GPS-lesson-plan.pdf|pdf]])
-
Air pressure also affected by weather - high and low pressures
+
{{lesson slide||}}
-
* needs to be recalibrated when the weather changes
+
'''WAAS'''
 +
* http://en.wikipedia.org/wiki/Wide_Area_Augmentation_System
 +
* http://www8.garmin.com/aboutGPS/waas.html
-
Can be bought as separate device, or built into watches, radios, cell phones.
+
Altitude/Azimuth calculator for WAAS geosynchronous satellites
 +
* http://www.csgnetwork.com/geosatposcalc.html
 +
* Altitude of 32 degrees around Pincher
-
Does not require clear view of sky. Works when GPS's fail.
 
-
Works indoors, in caves.
 
-
Only useful when elevation helps is determining location.
 
-
* e.g. following a feature (ridge line) until hit certain elevation
 
-
* e.g. traversing along same elevation until hit certain feature (creek)
 
-
* terrain has a lot of elevation details : big hills, mountains : Kananaskis, Waterton, BC
 
-
{{lesson slide|00:28|1 min}}
 
-
'''Satellite navigation systems'''
 
-
 
-
There are two satellite navigation systems available
 
-
* GPS - Global Positioning System
 
-
** controlled by the US military
 
-
** most commonly used
 
-
* GLONASS - Global Navigation Satellite System
 
-
** controlled by the Russian military
 
-
** starting to be found in devices
 
-
** works substantially the same as GPS and can be combined
 
-
 
-
Other systems will soon arrive from the Chinese and the Europeans.
 
-
 
-
{{lesson slide|00:29|3 min}}
 
-
'''How a GPS works'''
 
-
 
-
3 major components
 
-
* 1. radio receiver
 
-
** compares time for radio signal to arrive from satellites
 
-
** receives information on satellite locations
 
-
** optional WAAS: receives corrections to satellite location, signal distortions
 
-
* 2. computer
 
-
** computes where GPS currently is (needs 4 separated satellites)
 
-
*** 10-15m accuracy
 
-
*** applies corrections: ~ 1m accuracy
 
-
** records where GPS has been
 
-
** allows entry of remote locations
 
-
** calculates distance and direction between points
 
-
** calculate speed/time
 
-
** draw a route on a map
 
-
** place points on map
 
-
* 3. magnetic sensor (only some models)
 
-
** determines direction GPS is facing
 
-
** GPS without magnetic sensor tells what direction GPS has moved, but not direction GPS is facing
 
-
** test GPS by turning it. Does the direction arrow change?
 
-
 
-
{{lesson slide|00:32|10 min}}
 
-
'''How a GPS fails'''
 
-
 
-
radio signal not received from 4 satellites
 
-
* heavy tree cover
 
-
* blocked view of sky (hills, mountains, building)
 
-
* blocked view of geosynchronous WAAS satellites (32 deg elevation around Pincher Creek)
 
-
** North America only
 
-
* satellites not in right positions (below/at horizon, clustered)
 
-
* satellites not working/disabled (military selective availability)
 
-
* radio interference (jamming; spoofing)
 
-
* multipath (reflected) signals[3]
 
-
* weather does not affect signal
 
-
computer fails
 
-
* batteries (-15C)
 
-
* temperature (too hot)
 
-
* water/condensation (if not sealed)
 
-
* electromagnetic interference (industrial sites)
 
-
magnetic sensor fails (same as compass)
 
-
* metal (belt buckles, cars)
 
-
* magnetic fields (power lines)
 
-
* magnetic anomalies (far north)
 
-
 
-
{{lesson slide|00:42|4 min}}
 
-
'''Alternatives/Aids to GPS'''
 
-
* location: dead recogning / distance-bearing / triangulation
 
-
* recording: paper
 
-
* distance/direction: subtraction & estimation; plot on map
 
-
* map (better choice)
 
-
* bearing: compass (better choice)
 
-
 
-
 
-
{{lesson slide|00:46|7 min 7,6}}
 
-
'''When to use a GPS or other tools'''
 
-
discuss examples, compare with other alternatives
 
-
 
-
determine location when at
 
-
<table border="1">
 
-
<tr><th>determine location when at ...</th><th>GPS</th><th>Compass</th><th>Altimeter</th></tr>
 
-
<tr><td>hill top</td><td>+ </td><td>triangulate</td><td>helps</td></tr>
 
-
<tr><td>valley bottom</td><td>depends on tightness</td><td>triangulate</td><td>-</td></tr>
 
-
<tr><td>heavy trees</td><td>depends on type of trees, wetness</td><td>-</td><td>helps</td></tr>
 
-
<tr><td>canyon</td><td>-</td><td>helps</td><td>helps</td></tr>
 
-
<tr><td>south side of a lone hill</td><td>+</td><td>triangulate</td><td>helps</td></tr>
 
-
<tr><td>north side of a lone hill</td><td>poorer -- no WAAS</td><td>triangulate</td><td>helps</td></tr>
 
-
<tr><td>downtown city</td><td>multipath</td><td>poor: metal</td><td>-</td></tr>
 
-
<tr><td>under power lines</td><td>+</td><td>-</td><td>helps</td></tr>
 
-
<tr><td>heavy fog</td><td>+</td><td>-</td><td>helps</td></tr>
 
-
<tr><td>blizzard</td><td>+</td><td>-</td><td>pressure change?</td></tr>
 
-
<tr><th>determine direction/distance to ...</th><th>GPS</th><th>Compass</th><th>Altimeter</th></tr>
 
-
<tr><td>known UTM</td><td>+</td><td>direction only</td><td>elevation change</td></tr>
 
-
<tr><td>some place you can see</td><td>not helpful or only poor with magnetic sensor</td><td>direction only</td><td>-</td></tr>
 
-
<tr><td>some place you've been</td><td>sufficient if you recorded UTM</td><td>-</td><td>elevation change</td></tr>
 
-
<tr><td>a Lat/Long</td><td>sufficient</td><td>-</td><td>elevation change</td></tr>
 
-
<tr><td>a street address</td><td>for street GPS</td><td>-</td><td>-</td></tr>
 
-
<tr><th>other purposes ...</th><th>GPS</th><th>Compass</th><th>Altimeter</th></tr>
 
-
<tr><td>route selection</td><td>poor unless street</td><td>-</td><td>-</td></tr>
 
-
<tr><td>remembering a UTM</td><td>+</td><td>-</td><td>-</td></tr>
 
-
<tr><td>convert between Lat/Log and UTM</td><td>+</td><td>-</td><td>-</td></tr>
 
-
</table>
 
-
 
-
{{lesson slide|00:53|5 min 5,6}}
 
-
'''Significant configuration settings'''
 
-
 
-
Most GPS's allow you to configure:
 
-
* True North vs. Magnetic North
 
-
** use True North
 
-
** GPS's don't generally allow you to set declination to exact same value used on compasses.
 
-
* UTM vs. Lat / Long
 
-
** UTM generally used by SAR
 
-
* Map Datum: NAD27 vs NAD83/WGS84
 
-
** measurement of the shape of the Earth
 
-
** NAD - North American Datum
 
-
** WGS - World Geodetic Survey
 
-
** should use same as the topo map being used
 
-
** Pincher SAR maps generally NAD27
 
-
 
-
{{lesson slide|00:58|9 min}}
 
-
'''configure a particular model for local SAR usage'''
 
-
 
-
''Handout PCSAR GPS Configuration sheet''
 
-
 
-
''Exercise:'' Students configure their GPS
 
-
 
-
'''Help students to configure if their particular model not same as PCSAR GPS''
 
-
 
-
 
-
{{lesson slide|01:07|5 min}}
 
-
'''Long/Short UTM'''
 
-
 
-
''Assume students have basic background in UTM''
 
-
 
-
* ''Distribute: topo maps''
 
-
* ZEN (Zone Easting Northing)
 
-
* long form of numbers
 
-
** read off corner of topo maps
 
-
** northing: number of meters north of the equator
 
-
** easting: number of meters east of imaginary zone line (500km center line)
 
-
** converting to short form
 
-
 
-
{{lesson slide|01:12|5 min}}
 
-
'''Reading UTM on a GPS'''
 
-
 
-
* Read the current/last known UTM
 
-
** last location where GPS was turned on and could see satellites
 
-
** instructions on front of Pincher SAR GPS's
 
-
** determining accuracy
 
-
*** Garmin eTrex: on Satellite Page
 
-
 
-
{{lesson slide|01:17|8 min}}
 
-
'''GPS UTM exercise'''
 
-
 
-
''Exercise:''
 
-
* Record last known UTM in long form
 
-
** ''some GPSes may be sensitive enough to get fix in the classroom''
 
-
* Give last known UTM in short form
 
-
* assist students that don't have Pincher SAR GPS
 
-
 
-
{{lesson slide|01:25|10 min}}
 
-
'''Manual determination of Distance and Direction'''
 
-
* use map
 
-
* without map
 
-
** subtract Easting/Northing
 
-
** estimate distance or Pythagorean theorem
 
-
** estimate direction or calculate Tangent
 
-
** or draw scale map
 
-
''Example:''
 
-
* I'm at Zone:12U Easting: 0286623 Northing: 5484642
 
-
* I'm going to:12U Easting: 0287134 Northing: 5484419
 
-
* location is: 511 meters East and 223 meters South
 
-
* estimate: ESE 620m
 
-
* map/calculation: 129 degrees 661m
 
-
 
-
{{lesson slide|01:35|10 min}}
 
-
'''Choosing a GPS'''
 
-
 
-
Discuss GPS model selection/shopping
 
-
* Packaging: hand held, cell phone, car
 
-
* Features: sensitivity, WAAS, map, computer interface
 
-
* Brands: Garmin, Magellan
 
-
* Prices: low $200
 
-
 
-
{{lesson slide|01:45|1 min}}
 
-
'''Summary'''
 
-
 
-
Review objectives
 
{{lesson slides end}}
{{lesson slides end}}
Line 440: Line 223:
* 1 Brett Wuth's Garmin eTrex GPS
* 1 Brett Wuth's Garmin eTrex GPS
* 5 copies topo map of locale (82 H/5)
* 5 copies topo map of locale (82 H/5)
-
* [[PCSAR Doc-69 GPS Set Up and Maintenance]]
 
* copy for each student of local street map
* copy for each student of local street map
* copy for each student of PCSAR Doc-69 [[PCSAR DOC-69 GPS Set Up and Maintenance|GPS - Set-Up and Maintenance]]
* copy for each student of PCSAR Doc-69 [[PCSAR DOC-69 GPS Set Up and Maintenance|GPS - Set-Up and Maintenance]]
-
 
+
* copy for each student of outside exercise sheet, adapted to locale
-
* [[Image:GPS-lesson-plan.odt|GPS lesson plan (odt)]] ([[:Image:GPS-lesson-plan.pdf|pdf]])
+
* Radios
-
 
+
-
Alternate resources, deeper understanding:
+
-
* {{link|Image:Members:2013-02-20 00 52 44u-scan.pdf}}
+
-
* [[GPS/Skills]]
+
-
* Jamming: https://www.bbc.com/news/world-europe-46178940 ({{link|Image:Members:2018-11-12 BBC Russia suspected of jamming GPS signal in Finland.pdf|cached}})
+
-
 
+
-
 
+
-
* [[Training/Ideas/Instruments theory]]
+
== Question bank ==
== Question bank ==
Line 460: Line 234:
{{prompt|What are some of the questions that students typically ask. Include the answers.}}
{{prompt|What are some of the questions that students typically ask. Include the answers.}}
-
'''How does global compass work at any latitude?'''
+
* How does global compass work at any latitude?
From
From
Line 466: Line 240:
In the global compass, this problem has been solved with a structural innovation. The needle and magnet are built as separate units functioning independently from each other, so that the inclination of the magnetic field cannot tilt the needle. The needle can no longer move vertically. It is the compass magnet, separated from the needle, which absorbs the vertical force of the magnetic field. The needle itself is fixed at the lid by means of a double jeweled bearing. The magnet rotates with its jewel bearing on a pin. Such a compass works reliably in all zones of the world. Due to the strong magnet, the needle settles very quickly and stops immediately at the right position, allowing for an extremely accurate reading.
In the global compass, this problem has been solved with a structural innovation. The needle and magnet are built as separate units functioning independently from each other, so that the inclination of the magnetic field cannot tilt the needle. The needle can no longer move vertically. It is the compass magnet, separated from the needle, which absorbs the vertical force of the magnetic field. The needle itself is fixed at the lid by means of a double jeweled bearing. The magnet rotates with its jewel bearing on a pin. Such a compass works reliably in all zones of the world. Due to the strong magnet, the needle settles very quickly and stops immediately at the right position, allowing for an extremely accurate reading.
-
 
-
 
-
'''My GPS has EGNOS. What is that?'''
 
-
 
-
http://en.wikipedia.org/wiki/European_Geostationary_Navigation_Overlay_Service
 
-
 
-
EGNOS is similar to WAAS, but works best in Europe.
 
== Feedback ==
== Feedback ==
Line 480: Line 247:
{{prompt|What can others do with this lesson?}}
{{prompt|What can others do with this lesson?}}
-
Copyright © 2004-2013, Brett Wuth.
+
Recommended license below. Fill in the year and the author's name(s):
 +
 
 +
Copyright © YEAR, Author.
This work is licensed under a
This work is licensed under a
Creative Commons Attribution-NonCommercial 2.5 Canada License.
Creative Commons Attribution-NonCommercial 2.5 Canada License.
Line 490: Line 259:
{{prompt|If you need to cite sources, do so here.}}
{{prompt|If you need to cite sources, do so here.}}
-
http://www.rescuedynamics.ca/articles/MagDecFAQ.htm
+
[1]
== Notes ==
== Notes ==
{{prompt|Any additional notes, etc.}}
{{prompt|Any additional notes, etc.}}
-
 
-
'''WAAS'''
 
-
* http://en.wikipedia.org/wiki/Wide_Area_Augmentation_System
 
-
* http://www8.garmin.com/aboutGPS/waas.html
 
-
 
-
Altitude/Azimuth calculator for WAAS geosynchronous satellites
 
-
* http://www.csgnetwork.com/geosatposcalc.html
 
-
* Altitude of 32 degrees around Pincher
 
-
 
-
'''EGNOS'''
 
-
* http://en.wikipedia.org/wiki/European_Geostationary_Navigation_Overlay_Service
 
-
* has only one ground reference station in North America, so less accurate than WAAS here
 
-
 
-
 
-
'''GLONASS'''
 
-
* http://en.wikipedia.org/wiki/GLONASS
 
-
 
-
'''Galileo''' - European
 
-
* http://en.wikipedia.org/wiki/Galileo_%28satellite_navigation%29
 
-
 
-
'''COMPASS''' - Chinese
 
-
* http://en.wikipedia.org/wiki/Compass_navigation_system
 
-
== To Do ==
 
-
* Get example of altimeter
 
-
* Create a checklist sheet for shopping
 

Please note that all contributions to PCSAR are considered to be released under the Attribution-Share Alike 3.0 Unported (see PCSAR:Copyrights for details). If you don't want your writing to be edited mercilessly and redistributed at will, then don't submit it here.
You are also promising us that you wrote this yourself, or copied it from a public domain or similar free resource. DO NOT SUBMIT COPYRIGHTED WORK WITHOUT PERMISSION!


Cancel | Editing help (opens in new window)

Templates used on this page:

Retrieved from "http://pcsar.dyndns.org:8080/mediawiki/index.php/SAR_Fundamentals/Navigation_instruments_theory"
Personal tools