ARMY MOUNTAIN WARFARE SCHOOL

1. ARMY MOUNTAIN WARFARE SCHOOL . The materials in this document are as follows: Unclassified This document contains information exempt from mandatory disclosure under the Freedom of Information Act (FOIA).

2. ARMY MOUNTAIN WARFARE SCHOOL 8 Mountain School Road, Jericho, VT 05465 Disclaimer: Opinions and recommendations to any and all information pertaining to this class can be sent to the Army Mountain Warfare School Operations office: 802-899-7202/3/4/5 This product is based on doctrinal publications of the US Army. The intent is to share knowledge, support decisions, and impart information in an expeditious manner to Soldiers deploying and training in mountainous environments in all climactic conditions. The materials in this document are as follows: Unclassified This document contains information exempt from mandatory disclosure under the Freedom of Information Act (FOIA).

4. ARMYMOUNTAIN WARFARE SCHOOL ALTIMETER NAVIGATION 071E9012

5. Introduction • Safety Considerations • Risk Assessment • Environmental Considerations • Evaluations

6. Terminal Learning Objective • Action Employ the Altimeter / Barometer as a navigational aid and weather prediction device while dismounted. • Conditions In a classroom environment, given seasonal clothing and assigned equipment. • Standards Students must receive a GO in accordance with the Student Evaluation Plan.

7. ELO A • Action Implement the Altimeter/Barometer as a navigational aid. • Conditions In a classroom environment, given seasonal clothing and assigned equipment. • Standards Students must receive a GO in accordance with the Student Evaluation Plan.

8. Define the altimeter/ barometer • A device which, based on barometric pressure, can provide readings of elevation above and below sea level, and readings of barometric air pressure. • This is possible because air pressure decreases at a known rate with increasing altitude.

9. Identify the use of an altimeter/barometer • Locate Caches or Your Location • Route Planning • Monitor Your Progress • Determine Location During Periods of Poor Visibility • Interpret/Monitor Changing Weather

10. Locate Caches or Remote Locations in Difficult or Mountainous Terrain Cache

11. Determine Short-cuts or Alternate Routes OBJ You

12. Avoid Difficult Movements Cliff Faces OBJ You Gradual Ascent

13. Determine Location During Periods of Poor Visibility Mountain Top You (Elevation = 3,000 feet)

14. Identify altimeter specifications • The following list includes general specifications of an altimeter. • Range. The range is the lowest reading possible (usually below sea level) to the highest reading possible (usually up to 30,000 feet). • Accuracy. Different altimeters will sense elevation change at varying accuracy and from +/- 10 feet to +/- 30 feet.

15. Scale Units. The altitude scale can be either in feet or meters and the barometric pressure scale can be in inches of mercury (Hg) or millibars (mbar). • Field Display. The altitude will be displayed in either a digital or analog format, depending on the device. • NOTE: There are many different types of altimeters available. Check with the manufacturer for your device’s specifications.

16. Measure altitude differences using the altimeter You must know this to properly use the Altimeter/Barometer! • Set your present elevation from a known point. • Climb or descend to another elevation. • Re-check your altimeter. • Difference between first and second reading equals change in elevation. • Useful tool for route planning

17. Examples • Initial reading is 2,000 feet and the second reading is 2,480 feet = you have gained 480 feet in elevation • It has taken you 2.5 hours to climb 1,500 feet of a 3,000 foot climb and you know the trail will continue at the same degree of difficulty. You can estimate your arrival at objective to be approximately 5 hours.

18. Measure elevation readings above sea level using the altimeter • Adjust your altimeter to show true height above sea level (ASL) using supplied altimeter instructions. • Reset at known points. • Resection: Use one known point on the ground and contour lines to determine current position.

19. ELO B • Action Implement the Altimeter/Barometer as a weather interpretation device. • Conditions In a classroom environment, given seasonal clothing and assigned equipment. • Standards Students must receive a GO in accordance with the Student Evaluation Plan.

20. Interpret weather using the altimeter / barometer • Weather Forecasting: The altimeter/barometer also can be used to accurately interpret weather patterns in your location. • Check altimeter reading when you first arrive at a location. • If pressure then changes due to weather, the altitude will read higher or lower than the original reading. • REMEMBER: The higher the elevation, the lower the air pressure should be.

21. Interpret weather using the altimeter / barometer (cont) Altimeter reads a higher elevation, even though you haven’t moved – low pressure is moving in – bad weather. Altimeter reads a lower elevation, even though you haven’t moved – high pressure is moving in – good weather.

22. Elevation REMEMBER The higher you go in elevation, the lower the barometric pressure will be. Pressure

23. When stationary. . . • If your initial reading is 2,200 feet, and your next check is 2,300 feet… …then the pressure is falling. • Falling pressure indicates BAD weather.

24. When stationary. . . • If you initial reading is 2,200 feet, and your next check is 2,100 feet… …then the pressure is rising. Rising pressure indicates GOOD weather. Remember to adjust your altimeter back to the correct elevation (based on the known point you are at) before moving out.

25. ELO C • Action Implement a GPS device as an altimeter. • Conditions In a classroom environment, given seasonal clothing and assigned equipment. • Standards Students must receive a GO in accordance with the Student Evaluation Plan.

26. Identify the differences between using an altimeter or a GPS • Altimeter determines elevation by measuring the weight of air either electronically or mechanically. • GPS determines elevation through the triangulation of 4 or more satellites. • By using only triangulation a GPS cannot be used as a weather prediction device. • Be careful of mathematical variations.

27. GPS elevation • GPS requires 3-4 satellites, low on horizon for best readings. • Mountainous terrain can mask satellite signals, preventing a good reading.

28. What gives a “Good” GPS elevation? • One satellite directly above • Three low and spread around GOOD BAD

29. GOOD DISPERSION – BAD VISIBILITY

30. SUMMARY Reset at every known point Falling pressure = bad Rising pressure = good

31. Questions?

32. References • FM 3-25.26 Map Reading and Land Navigation • FM 3-97.6 Mountain Operations • FM 3-97.61 Military Mountaineering • FM 5-19 Composite Risk Management

33. End of Conference

34. SUUNTO VECTOR

35. SUUNTO VECTOR BAROMETER MODE TIME COMPASS ALTIMETER

36. PUSH & HOLD “SET” UNTIL UNITS FLASH PUSH “MODE” UNTIL ‘ALTI’ IS SELECTED ALTIMETER SET PUSH MODE AGAIN TO SAVE PRESS TO DECREASE PRESS TO INCREASE

37. COMPASS USE KEEP BUBBLE CENTERED COMPASS MODE

38. TIME CHANGE/SET PUSH MODE UNTIL TIME MODE PUSH & HOLD SET PUSH SET TO HIGHLIGHT BLINKING UNITS PUSH MODE TO SAVE CHANGES USE UP/DOWN TO CHANGE UNITS