ES Aircrew2009 Update Training

ES Aircrew2009 Update Training

U.S. AIR FORCE AUXILIARY

U.S. AIR FORCE AUXILIARY

Lt. Col. Stan KegelMinnesota Wing April 2009

US National GridAwareness

US National GridAwareness

Agenda

Our goal today:– Become familiar with the US National Grid (USNG)

In short, what is it? How does it relate to other common grid and coordinate systems? In what situations does it work well? Where did this requirement come from? Who must use it and when? What complications exist?

This course is only and introduction and is not intended to fully teach the ability to use USNG in navigation

What is USNG?

A GRID System– Each numbered grid describes a square area (not a point like

Lat/Long)– Supports grids of many scales, from 100 km down to 1 meter (or,

theoretically even smaller)– Flat, square coordinate system– Seamless with respect to political boundaries– Truncated (abbreviated) form can be used often (when context tells

us what part of the country is relevant) Based on UTM (Universal Transverse Mercator) Coordinates

– USGS topographic map “Grid North” refers to the UTM (and USNG) coordinate system

USNG & MGRS

MGRS – Military Grid Reference System– NATO Standard

USNG is nearly the same as MGRS– Declared a separate standard so each can be free to change

to meet the needs of its audience in the future– Right now completely equivalent if the NAD83/WGS84 datum

is used Differences in notation if other datums are used

– One of its benefits of the adoption of the USNG standard is that military personnel essentially already know it (and they are often acting in support of catastrophic incidents)

UTM Basics – Big Pictures

08/27/98

UTM/USNG Grid Zone Designations126° 120° 114° 108° 102° 96° 90° 84° 78° 72° 66°

10 11 12 13 14 15 16 17 18 1924°N

32°N

40°N

48°N

S

R

U

T

UTM “zones” every 6 degrees of longitude Latitude band every 8 degrees of latitude “Grid zone designation” (GZD)

– A combination of zone andlatitude band

Each “grid zone” has its own map projection.

– Most of Minnesota is in grid zone 15T

UTM Basics – Coordinates

A Northern Hemisphere UTM Location is given as…– Grid Zone – “Easting”

Measurement (in meters) east/west of the central meridian of the zone

The central meridian is given a value of 500,000 meters to avoid negative numbers

Numbers greater than 500,000 are east of central meridian– “Northing”

Measurement (in meters) north of the equator Example: 15 511196 4982565

(Point on St Paul, Lake Elmo Airport)

USNG Grids – Differences from UTM

Grid zones broken up into “100,000 m Squares”– Caveat: On the edges of the Grid zone, the 100,000 m squares are

not square. Each “Square” is given a two letter “ID” The IDs are arranged so that the same ID occurs only a few times

in the country and always a long way away– This allows for “truncated” grid references

(i.e. omitting the GZD and the 100,000 m Square ID) The use of 100,000 m Squares means that we don’t need the first

2 digits of the UTM Northing and the 1st digit of the UTM Easting, so these digits are omitted from USNG grid coordinates

USNG Grid Coordinates

In full form, given as…– Grid Zone Designation– 100,000 m Square ID– Easting and Northing numbers

Always with same number of digits for each part The number of digits defines the grid size/precision

– Four digits: 23 06 Locating a point within a 1,000-m square– Six digits: 233 065 Locating a point within a 100-m square

(football field size)– Eight digits: 2337 0651 Locating a point within a 10-m square

(modest size home)– Ten digits: 23371 06519 Locating a point within a 1-m square

(parking space size)

Example: 15T WK 11196 82565 (Point on St Paul Lake Elmo Airport)

Truncated form omits GZD and 100,000 m Square ID

Comparing Coordinates

St Paul Lake Elmo Airport– UTM: 15 511196 4982565 – USNG: 15T WK 11196 82565 – Lat/Long: 44 59.78’ N 92 51.48’ W

St Paul Downtown Airport– UTM: 15 494689 4976117– USNG: 15T VK 94689 76117 – Lat/Long: 44 56.30’ N 93 04.03’ W

USNG – Minnesota

USNG – Big Picture View

Strengths

For terrestrial navigation– Not for aeronautical/maritime use

Works best over relatively small areas– The land can be modeled reasonably as a flat area

when working in small areas

Who is driving this, and why?

NSARC – National SAR Committee (DOD, DHS, et. al.)– Addressing Katrina SAR Issues:

How do SAR Responders navigate when landmarks are destroyed

Need for a grid system for SAR planning (resource deconfliction, etc.)

– Practical difficulties using Latitude and Longitude for terrestrial small area navigation.

USNG: What scenarios are driving this?

“Catastrophic Incident” SAR– Think Hurricane Katrina– Think 35W Bridge Collapse

Catastrophic Incident SARNSARC Georeferencing Matrix

Georeference System User USNG

Latitude/Longitude

DD-MM.mmm [1] GARS

Land SAR Responders [2] Primary Secondary N/A

Aeronautical SAR Responders [3] Secondary Primary Tertiary

Air Space De-confliction [4] N/A Primary N/A

Land SAR Responder/Aeronautical SAR Responder Interface [5]

Primary Secondary N/A

Incident Command:

Air SAR Coordination

Land SAR Coordination

Secondary

Primary

Primary

Secondary

N/A

N/A

Area organization and accountability [6] Secondary Tertiary Primary

NSARC Georeferencing Matrix Footnotes

1. During CIS operations, Lat/Long will be in one standard format:

DD-MM.mmm

2. Land SAR Responders must use USNG; however a good familiarity with lat/long is necessary to ensure effective interface between land and air SAR responders

3. Air SAR Responders will use Lat/Long

NSARC Georeferencing Matrix Footnotes

4. Air space deconfliction: only in Lat/Long

5. Air SAR Responders working with land SAR responders have primary responsibility of coordinating SAR using USNG Both need to know USNG and Lat/Long

6. GARS (Global Area Reference System): used for CIS response leadership situational awareness

What about Lat/Long?Couldn’t a grid system be built on that?

Lat/Long:– Great system for larger area navigation but…

Distances not easy to figure out– How far is 1 degree of longitude?– Shorter distances get even more awkward.

(How far is 0.1 minutes of longitude?) Difficult to accurately plot positions (or grids) based on Lat/Long

with using a topo map

In small areas, it is easier to think in terms of linear distances (feet, meters, kilometers, miles, etc.)

– Example: Go 100 m east, then 200 m north

Would a scrolling-map GPS device solve the problem?

GPS devices are great for providing position info … in a variety of possible display formats

Lat/Long (DD MM.mmm, DD MM SS.s, …) UTM USNG etc.

They are horrible maps, however

Complications to expect

UTM/USNG awkward at and near grid zone boundaries

Using USNG On a Topo Map

USNG on a Topo Map

Plotter for Use for USNGOn Topo Maps

The Example on the Big-Picture

Example - Truncated

Questions