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What's New?  See changelog / release-notes page.

SOTA (Summits-On-The-Air) and POTA (Parks-On-The-Air) are awesome awards schemes that gives points for hiking up mountains or visiting parks and making amateur radio (ham radio) contacts. It combines exercise, vistas, emergency drill practice, self-competition, and social benefits, Learn more about SOTA here and here, or POTA here.

Have you tried activating a SOTA/POTA peak but had trouble self-spotting? Do you feel ‘dirty’ self-spotting an amateur radio activity with non-amateur cell-phone or satellite methods? Do you wish you had a simple way to find Summit-to-Summit (S2S) opportunities? Do you wish you could send a message to a friend, but cell and APRS services were spotty in the mountains?

SOTAmāt (pronounced “sota mate”) automates a variety of SOTA/POTA activities. Current services include:

  1. Self-spotting over HF (SOTA and POTA)
  2. Self-alerting over HF for CW operators wishing to “tickle” RBNhole (SOTA)
  3. Send predefined SMS messages over HF
  4. Find Summit-to-Summit opportunities with recent spots reports over SMS or Satellite (SOTA)

Self-Spotting (and Alerting) over HF

The SOTAmāt server listens to PSKreporter for reception reports of your (preregistered) callsign with a special SOTAmāt suffix (specific to your personal SOTAmāt configuration). This callsign suffix encodes a command for SOTAmāt to execute (such as a self-spot for a particular summit-ID / park-ID, or to send an SMS message).

SOTAmāt workflow

In the field (without cell service) you use a mobile application (iOS or Android) to compute a callsign suffix based on your preregistered personal configuration and the command you want to execute (ex. a self-spot of W6/NC-001 14.227 MHz SSB). You then transmit a message using any method that will report your callsign + suffix to PSKreporter. For example, you can send your message using FT8, RTTY, PSK, or any method that preserves the suffix.

For example, if my account were configured correctly, this FT8 message:


Might self-spot me as follows (on SOTA Watch):

AB6D on W6/NC-423 14.277 SSB [SOTAmat.com by FT8] Freq +/- if QRM. (via KF7PRQ via AB6D)

And the hardware is quite simple:

…in fact you don’t even need a cable from the mobile phone to the radio. When your surroundings are quiet (not a lot of wind) you can just have the mobile phone speaker play the FT8 sounds directly into your radio’s microphone (see the FAQ article on how to improve the signal-to-noise ratio when cable-free to make sure you don’t transmit background noise / splatter).

Unfortunately not all monitoring software preserves the suffix on the way to PSKreporter, such as CW (the RBN CW ‘skimmer’ monitoring software doesn’t know how to discriminate between callsign suffixes-as-locators vs. suffixes-as-indicators). I find the most reliable (and known to work) approach is to use FT8 (there just aren’t many PSK or RTTY monitoring stations left these days). Use one of the newly available iOS (HOTPAW FT8) and Android FT8 (VU3CER FT8) applications (no computer required to send FT8 in the field!). The SOTAmāt iOS app knows how to directly connect to the HOTPAW FT8 iOS app and provide it the complete SOTAmāt message string. With VU3CER (Android) you currently need to cut-and-paste the SOTAmāt string into the Android app, and change the audio frequency (it defaults to 500 Hz, but for mobile phone speakers 1400 Hz is better!).

Note that normal FT8 CQ messages do not allow a callsign suffix (there are not enough FT8 ‘C28’ bits). The current version of SOTAmāt sends messages in FT8’s 13-character “free text” mode, and only SparkSDR monitoring stations seem capable of extracting callsigns + suffixes from these messages (I’ve reached out to Joe Taylor to change that!). Thus, only a fraction of the FT8 monitoring stations in PSKreporter’s network will report on your SOTAmāt messages. Since FT8 can travel for 1000’s of miles using QRP, I find that I’m able to reach at lesat one SparkSDR based monitoring station reliably (normally 3 or 4 will hear me) if I transmit my FT8 message 3 or 4 times. Your experience may differ. In really tough conditions (sunspot cycle blackouts?), you might need to send your FT8 message on different bands. I’ve always gotten through if I’m patient.

Sending SMS messages

Certain callsign suffixes instruct SOTAmāt to send predefined SMS text messages on your behalf. The process works the same way self-spots work: you first preconfigure a set of SMS messages on the web site and load them into the mobile app for offline use. In the field, use the mobile app to select a predefined message and the app will compute the corresponding callsign + suffix. Send the message using any means that will arrive in PSKreporter with the suffix unchanged (such as with an FT8 mobile app). In about 5 minutes or less your SMS message should be sent.

NOTE: SOTAmāt should not be used for life safety situations. The service is not designed for highly reliable message delivery. It does not use professionally designed systems or architectures. It is not a replacement for satellite communicator devices. Use of the service is at your own risk! The system is not guaranteed or warranted to perform. It is built and run as a hobby by its creator.

Recent Spots Report

.If you do have cell service or a satellite communicator (such as a Garmin InReach), you can send a specially formatted SMS message to +1-601-SOTA-MAT (+1-601-768-2628) in order to get:

  • SOTA Spots: A list of recent SOTA spots (in the last 60 minutes). This can be useful if you want to know about Summit-to-Summit (S2S) opportunities. The command has several synonyms: “spots”, “sotaspots”, “ss”, “sspots”.
spots [all|cw|ssb|fm|data|other] [count] [s|short]
  • SOTA Alerts: A list of recent (several minutes of the past) and upcoming (in the next 3 hours) SOTA Alerts. The command has several synonyms: “alerts”, “sotaalerts”, “sa”, “salerts”.
alerts [count] [s|short]
  • POTA Spots: A list of recent POTA Spots (in the last 60 minutes). This can be used to find park-to-park (P2p) opportunities. The command has several synonyms: “potaspots”, “pspots”, “ps”.
Pspots [all|cw|ssb|fm|ft8|...] [count] [s|short]
  • The first [mode] parameter filters which types of recent spots it will report on. Use “all” if you want all modes. This parameter is optional and defaults to “all“.
  • The [count] parameter is an integer for the maximum number of recent spots/alerts you want returned (it may return less than this number if there were fewer matching items available in the last 60 minutes). The [count] parameter is limited (10 maximum for spots, 15 for alerts). If omitted, the default value is 5.
  • The optional [short] option is intended for users of satellite communicators (ex. Garmin InReach) where SMS messages over (about) 100 characters are often received in out-of-order chunks. Satellite services often charge based on the length of the message. The “short” option strips away all the optional information and provides only the most important data. By default, [short] is not enabled. The [short] option can be abbreviated as [s].

Here are some examples of what to send to the +1-601-SOTA-MAT (+1-601-768-2628) service:

spots ssb 3
The “long” format, intended for cell phones over SMS
spots all 4 short
The “short” format, intended for satellite communicators

The following examples are all valid commands:


…is equivalent to: “SotaSpots all 5”

ss s

…is equivalent to: “SotaSpots All 5 short”

sa 4 s

…is equivalent to: “SotaAlerts 4 short”

NOTE: the SMS service costs me money to operate. When you add the per-block fee (inbound and outbound), plus taxes, etc. it works out to about $0.05 USD (5 pennies) per round-trip exchange (3 blocks on average). For now I’m happy to pay this for the benefit of the community. It is OK to send a few test messages when you are learning how to use the service, but after you understand it please only use the service for real SOTA/POTA work (don’t waste it!). If it is abused I will have to go to an account registration based approach, and nobody wants that (myself included!).

Get started

For ‘Recent SOTA Spots Report’ via SMS:

Registration isn’t required: you can start using it now. Read the instructions above.

For POTA/SOTA ‘Self-spotting’ and ‘Messaging’ via HF:

First watch the two tutorial videos to get the basic ideas:


  1. Register a new account on this web site: you must use your callsign as your username!
  2. Prepare your personal configuration on this web site. Follow the instructions on the “PREPARATION” menu above. You must configure either:
    1. “Regions” / “Locations” and “Freq/modes”, or
    2. Some SMS message commands, or
    3. Both (1) and (2) above.
  3. Install the SOTAmāt mobile app: in Beta the apps are not yet in the Apple App Store or Google Play store, they are in the beta app stores:
    1. iOS: first install the Apple “TestFlight” app for Beta apps. Once “TestFlight” is installed, you can access the iOS SOTAmāt app here (open the link on the iPhone).
    2. Android: here are the Android SOTAmāt app APK builds
  4. Install a mobile app for modulating FT8:
    1. iOS: HOTPAW FT8
    2. Android: VU3CER FT8

73 DE AB6D