APRS is a registered trademark Bob Bruninga, WB4APR Copyright © 2003 – John Beadles, N5OOM All Rights Reserved APRS for Public Service Events John Beadles,

APRS is a registered trademark Bob Bruninga, WB4APR

Copyright © 2003 – John Beadles, N5OOMAll Rights Reserved

APRS for Public Service Events

John Beadles, N5OOM



APRS in Public Service Events

• APRS is a tactical aid to event management – not intended to be a replacement for voice

• It helps the Net Controller track the location of assets

• Is best when most (or at least the most critical) stations have it.

• Is best when all the equipment is tested out before hand (don’t wait until the last minute and expect it to work)

• Bicycle rallies, races

• Foot races

• Parades

• Crime prevention patrols

• Weather nets

• Damage assessment

• If your organization is new at it, establish a pre-event workshop to get your participants’ equipment working



Types of APRS Stations

• Control Stations – Radio, TNC and Computer – provides a display that the Net Controller uses to track the location of assets

• Digipeaters – Repeats APRS packets. Many areas have Regional networks of WIDE and RELAY digipeters; however, some events may be held in terrain where a public fixed digipeater can’t hear, so a temporary digipeater may be necessary.

• Weather Stations – A Weather Station tied to an appropriately configured TNC or WeatherTrak and a Radio.

• Telemetry Stations – Can be used to transmit the status of sensors. KPC-3+ TNCs have some telemetry capability.

• Mobile Trackers – An APRS station consisting of a GPS receiver, TNC and radio mounted in a vehicle, generally not intended to be relocated. Generally tied to the vehicle’s power. Could also be a boxed APRS station that is intended to be placed in locations or vehicles on a temporary basis. May use a mobile or HT as a radio, might use a TNC or TinyTrak unit. Might have internal batteries.

• Personal Trackers – An APRS station intended to be worn. Might be used for search and rescue events. Probably uses an HT as a radio.



Control Stations

144.39

Mobile RadioTNC

An APRS master station is used by the net control and other interested parties to view the location of APRS stations. A laptop is not generally needed except by people who need to know where others are.



Net Control Station used during the 03 Red Hot Chili Pepper Rally

Jim Shultz W5OMG using a Kenwood TH-D7 and a laptop



Digipeater

TNC144.39

Mobile Radio

Battery

A digipeater only repeats packets that it hears. It doesn’t need a GPS receiver to do this. A fixed station might run off an AC power supply, while a portable station can run off a battery. Generally only a few fixed digipeaters are needed, though some mobile digis may be needed in certain circumstances. Improper digi configuration can harm the local network.



Weather Stations

144.39

Mobile RadioTNC

Weather Station TinyTrak144.39

Mobile Radio

Weather Station

144.39

Mobile RadioTNC

Weather Station

A weather station may be used for APRS using a WeatherTrak (similar to the TinyTrak), a suitable TNC or to a computer running appropriate software. Temporary weather stations are of limited utility for most public service events.



Mobile Stations

144.39

Mobile RadioGPS

Kenwood TM-D700

GPS

144.39

Mobile RadioTNC

GPS

TinyTrak144.39

Mobile Radio

Mobile trackers are intended to be carried in a vehicle. Usually uses a higher power mobile radio. May be installed in the vehicle or carried in a box and powered with a battery. Kenwood TM-D700 radios can have a laptop attached at the same time as a GPS receiver.



Portable Trackers

GPS

Palm

Battery

TNC

HT

144.39

A personal tracker is wearable or back-packable. It is likely to be low powered and may require a nearby digipeater. Might be used for event shadows or search & rescue personnel. A simple portable station may only include a GPS receiver, TinyTrak and radio. A more complex station might use a KPC-3+ and a Palm running PocketAPRS

HT

144.39

GPS TinyTrak



Trackers used during the 03 Red Hot Chili Pepper Rally

W5DCR

Dallas REACT

W5ADC

Mag-mounted

to outside of a

vehicle

N5OOM

Carried in a

vehicle

WA5KXX

Self-contained

digipeaters



Preparing for a PSE with APRS

• The PSE Coordinator – is the person in charge of the communications plan for the event. Can delegate labor to subordinates, including:

• The APRS Coordinator – Setting up the APRS can be labor intensive – the PSE coordinator may delegate this to an APRS expert.

• The Net Controller – Should coordinate with the APRS coordinator in advance of the event to determine what APRS functions will be available

The APRS Coordinator should:

• Map the route – if a race or rally, the route should be digitized and installed in the event’s net control station and

• Create and distribute maps and overlay files to the Net Controller, other interested parties

• Identify and list the APRS hardware that the volunteers will be bringing – insure that critical areas are covered. May borrow equipment if needed.

• Verify digipeater coverage on the route, coordinate the placement of temporary relays

• Ensure that all stations are properly configured.

• Oversee the installation of temporary trackers where needed. Note – this is labor intensive – plan on having an assistant or two.



During the event

• Before the event start, the APRS coordinator oversees the deployment of trackers. Better have an assistant if you have a lot of trackers!

• The coordinator uses a control station to see if all of the stations can be seen through a digipeater.

• During the event, the coordinator checks for holes in digipeater coverage, places temporary relay digipeaters as necessary.

• After the event, the coordinator collects any loaned equipment.



Preparing APRS for Emergency Service

• Emergency response events are necessarily come-as-you-are events. Emergency coordinators need to be familiar with the APRS coverage in their county.

• Similarly, ARES / RACES orgs that intend to incorporate APRS into their operations need to identify what percentage of their members have APRS equipment and what type of equipment is available to them.

• There are a fair number of APRS weather stations across N. Texas. However, most aren’t useable because they are uncalibrated or improperly installed. Possible for ARES / RACES orgs may provide installation / calibration instructions to fix.

• APRS users need to practice with their equipment to get the best use out of it. Perhaps orgs wishing to incorporate APRS should sponsor local workshops, sponsor group eqpt purchases.



UI-View Map for the 03 Red Hot Chili Pepper Rally

•Route marked on map

•Overlay used to identify specific points

•Different software packages provide different functionality

•Work needed to create a suitable map can vary greatly – beyond the scope of this presentation



Useful software functions for Net Controls

• Exclusions – Some software lets the user set a filter on the displayed stations. This is useful for eliminating clutter.

• Translations – Some software allows the user to assign a tactical tag to a station, so that the tag is displayed instead of the real call. This allows the net controller to more quickly identify stations

• Overlays – Overlays .are files that contain APRS formatted objects that will be displayed on top of the map. This is useful for marking known fixed locations, such as rest stops

• Objects – Objects are APRS markers, similar to those displayed for station beacons, but where the location can be manually entered. Some software allows stations to transmit the locations of fixed sites to other stations

• IGATES – An IGATE acts as a portal that gates APRS traffic from RF to and from the internet. This allows local APRS traffic to be seen at greater distances than would ordinarily be possible.

• Kiosks – Some software provides kiosk functionality. A kiosk allows remote stations to query it for information on specific topics. This could be useful for storing frequency lists, locations of landmarks, etc.

• Digipeaters – A digipeater is a station that repeats incoming packets, similar to a voice repeater. Some software contains digipeater functionality, which may be useful if the control station is in an area where digipeater coverage exists.



Software functions that would make APRS more useful

• Current software doesn’t appear to be optimized for by PSE net controllers. Some common functions need to be automated and easily accessable

• User interface limitations make it difficult for the net controller to rapidly switch between views (i.e. Switching from a station search to a weather station display)

• Need a way to isolate and locate stations on the map very rapidly

• Station objects on the map need to change color with age so the net control can see when that station last beaconed

• Needs to be a way for stations to collect data and send it to the net control. This would be very useful for post-disaster management, SAR events.

• Needs a way a reporting mechanism for handing collected data to emergency management officials

Documents

APRS is a registered trademark Bob Bruninga, WB4APR Copyright © 2003 – John Beadles, N5OOM All Rights Reserved APRS for Public Service Events John Beadles,