// pico balloon operationsPico Balloons Use the Global Standard
High-altitude pico balloon trackers represent one of the most demanding LoRa APRS use cases — they must be received by iGates hundreds of kilometers away, on every continent, with only milliwatt transmitter power. All pico balloon operators use the global standard settings for this reason, and any local iGate running non-standard settings creates a blind spot for balloon tracking.
Global reception
A balloon circumnavigating the globe must be received by iGates in Europe, Asia, the Americas, and Australia — all running SF12 / BW125. Non-standard iGates simply cannot hear it.
Extreme altitude range
At 10,000–15,000 m altitude, a balloon has line-of-sight to iGates hundreds of kilometers away. SF12’s sensitivity is crucial for closing that link on milliwatt power.
Ultra-low power
Pico trackers weigh grams and run on coin cells or tiny solar panels. SF12’s receiver sensitivity means transmitter power can stay at 10–100 mW while still reaching ground stations reliably.
| Frequency | 433.775 MHz |
| Spreading Factor | SF12 |
| Bandwidth | 125 kHz |
| Coding Rate | 4/5 |
| TX Power | 10–100 mW |
| Tracker weight | < 5 g typical |
| Altitude | 8,000–15,000 m |
| Beacon interval | 1–2 minutes |
| Path | None (NOGATE) |
// operating practicePico Balloon Operating Guidelines
Pico balloon operations have some specific considerations that differ from ground-based trackers. The most important is the use of no digipeater path — at altitude, direct iGate reach makes digipeating unnecessary and wasteful.
No path required
At cruise altitude (10,000–15,000 m), a balloon’s radio horizon extends hundreds of km. It will reach multiple iGates directly with no digipeating needed. Setting a digi path wastes channel time for everyone below and gains nothing for the balloon.
NOGATE or no path
The standard is to transmit with no path at all, or explicitly set NOGATE to prevent iGates from injecting the packet into the APRS-IS network in a way that could cause duplicates. Check the specific firmware you’re using for the exact setting.
Smart 1–2 minute beacon
Pico balloons typically beacon every 1–2 minutes. At altitude, multiple iGates will receive each packet, so delivery rates are very high even at moderate beacon intervals. More frequent beaconing adds unnecessary channel load globally.
// coverage implicationsNon-Standard iGates Create Blind Spots
Because LoRa signals are only received by radios with matching SF, BW, and CR settings, a balloon running the global standard cannot be heard by any iGate running different settings, even if that iGate has a perfect antenna and line-of-sight to the balloon. This is not a signal strength problem — it is a modulation incompatibility at the physical layer.
What a tracking gap looks like
On aprs.fi, a balloon track will show a continuous path of position updates where standard iGates exist, and then a gap — possibly hours long — where it passes over regions with non-standard or missing iGate coverage. The balloon keeps transmitting; nothing receives it.
How to help
If you’re in Arizona, SoCal, or any underserved region, deploying a standard-configuration iGate (SF12 / BW125 / 433.775 MHz) contributes directly to uninterrupted global balloon tracking. Even a modest indoor antenna at moderate elevation can provide significant coverage at altitude.
// getting startedBalloon Tracker Hardware & Firmware
Pico balloon trackers are typically custom-built to achieve the minimum possible weight. Several open-source designs are in wide use. The key requirements are: SX1276 or SX1278 LoRa module, GPS receiver, and a microcontroller with enough processing power to run APRS encoding — all at absolute minimum weight.
Typical hardware stack
- LoRa module: SX1276/SX1278-based (HopeRF RFM95, Ebyte E22, or similar)
- GPS: Ultra-low-power module — UBlox MAX-M8 or similar
- MCU: ATmega328P, STM32, or RP2040 depending on design
- Power: Lithium coin cell(s) or thin-film solar + small LiPo
- Antenna: Simple quarter-wave wire, or printed PCB antenna
Community & resources
The pico balloon community is active and well-documented. The best place to find current tracker designs, flight reports, and iGate coverage discussions is:
- LoRa APRS Discord — active balloon operators, firmware discussion
- aprs.fi — live balloon tracking
- lora.ham-radio-op.net — LoRa-specific station map
Search aprs.fi for active balloon callsigns (often containing “BALL” or “PICO”) to see live flights and study their tracks for coverage gaps.