learn

Best Practices for Accurate GNSS Data Collection with Consumer Devices

Applies to: Smartphones, tablets, handheld GPS units, drones (non-corrected GNSS)

---

Key practices for Maximizing Location Precision and Accuracy

---

1. Get a Clear View of the Sky

• Use in open areas, away from buildings and tall trees.
• Avoid dense canopy, walls, vehicles, or anything blocking the sky.
• Keep the device away from your body and metal surfaces.
• Once a lock is established (see soaking below) moving closer to these objects is fine, but the accuracy+precision may degrade

---

2. Soak the Signal Before Recording

• Wait 2–5 minutes at a new location before collecting data.
• Moving <1km is fine to collect, it’s moving significantly away that requires soaking.
• This allows the device to fully connect to available satellites.

---

3. Use Point Averaging

• Stay completely still for 30–60 seconds while collecting a point.
• Use averaging tools in your app or GPS if available.
• No tool? Take multiple points and average them manually.

---

4. Enable Multi-Constellation GNSS

• Use devices that support NavStar/GPS + GLONASS + Galileo + BeiDou.
• Ideal combination is GPS/NavStar + Galileo
• On phones, enable High Accuracy Mode (Android) or Location Services (iOS).

---

5. Monitor Satellite Geometry (HDOP/PDOP)

• Collect data when HDOP < 1.5 for better precision.
• Avoid collecting when HDOP > 2.5.
• Use apps that show HDOP (e.g., GPS Status, Field Maps, Locus).
• https://www.gnssplanning.com/ can be used to plan in the future or see past possible signals

---

6. Don’t Move While Recording 🚷

• Movement = position jumps.
• Use a tripod, or hold the device steady at chest or eye level.
• If recording a line, move more slowly or be prepared to edit the line later

---

7. Minimize Interference

• Keep the device away from large metal objects, electronics, radios, and terrain or large rocks.
• Metal and glass surfaces can reflect signals (multipath error)
• Blocking signal line of sight

---

8. Plan for Good Timing

• Satellite alignment changes during the day.
• If possible, collect data during times of low HDOP.
• Avoid collection during solar storms (check NOAA space weather).

For more info or to get an HDOP planning app, try:

• GPS Status & Toolbox (Android)
• GNSS View (iOS)
• Trimble GNSS Planning Online

Summary Chart

Factor	Recommendation	Benefit
Line of Sight	Open sky, away from buildings/canopy	Better satellite visibility
Soaking	Wait 2–5 min before capture	More stable satellite lock
Averaging	Stay still 30–60 sec, use averaging tool	Reduces random jitter
Satellite Geometry	Use apps to monitor HDOP < 1.5	Higher positional certainty
Constellations	Enable GPS + GLONASS + Galileo	More satellites = better fixes
Motion	Don’t move during data collection	Increases precision
Interference	Avoid metal/electronics, hold away from body	Reduced signal distortion
External Antenna	Optional for handheld or Bluetooth GNSS	Enhanced reception, better multipath resistance
Time of Day	Plan for low HDOP periods	Better accuracy from better geometry
A-GNSS Mode	Disable for satellite-only tests	Pure GNSS performance measurement