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The APS-3L features a high precision GNSS satellite receiver with embedded L-Band capability, designed to provide seamless RTK and Precise Point Positioning to the surveying market.

Integrated with state-of-the-art technology, the APS-3L provides surveyors with high productivity, performance and flexibility. When out of wireless range of terrestrial UHF radios or cellular networks, the APS-3L seamlessly transitions to L-Band corrections for decimeter level positioning.

GPS + GLONASS RTK and Precise Point Positioning (PPP) with L-Band corrections from TERRASTAR is delivered in a small and light design for ultraportability. For RTK, the APS-3L has an integrated GSM/GPRS modem for easy Real Time Network connection, and a digital UHF transceiver for Base/Rover operation on demand.

For ease of use and simplicity, the APS-3L is completely configurable from the data collector via Bluetooth for Base/Rover operation with the internal UHF radio, for Network Rover operation with the internal GSM/GPRS modem or for PPP with L-Band corrections.

APS-3L Features

  • 136 Channel GPS + GLONASS + SBAS + L-Band receiver
  • Seamless transition between RTK & PPP
  • Integrated Quad-Band GSM/GPRS Modem
  • Integrated UHF transceiver, 406-470 MHz
  • Integrated Bluetooth
  • Two Hot-Swap Li-Ion Batteries with Fuel Gauge
  • Removable 2 GB SD Card

With Altus’s open architecture philosophy, the user has the choice of data collector software from MicroSurvey FIELDGenius or Carlson SurvCE to custom software.

Note: The TERRASTAR L-Band correction service requires a subscription. The service is for land operations only.

The APS-3L is ready to use direct from the shipping case.

APS-3L Benefits

High Productivity

  • Seamless RTK & Precise Point Positioning (PPP) operation
  • Choice of integrated Cellular or UHF devices for RTK.
  • TERRASTAR D for 10 cm with without need for a base station or network.
  • High capacity hot swappable Li-Ion batteries.
  • Data collector software with intuitive ease-of-use for all features.
  • Lightweight and compact unit designed for ultra portability.


GNSS Performance

  • RTK accuracy at 1 cm & PPP at 10 cm
  • GNSS Receiver with GPS, GLONASS, & SBAS
  • RTK performance within minutes from cable free operation with wireless devices completely integrated into a compact system



  • L-Band is integrated into the GNSS so only a subscription is required for PPP with TERRASTAR.
  • Each unit can be a Base or Rover unit with no additional equipment purchase.
  • Internal Digital UHF transceiver programmable over full UHF band 406-470 MHz. Compatible with Pacific Crest, Satel, and Trimble radio protocols.
  • Quad-band GSM module for worldwide cellular use.
  • Removable SD Card enables plug and play raw data transfer for post processing.
  • External DC power input for continuous operation.

APS-3L Specifications

Channels 136
DGPS H: 0.50 m,     V: 0.90 m
RTK H: 0.6 cm + 0.5 ppm,     V: 1 cm + 1 ppm
Output Rate
H: 0.10 m,     V: 0.20 m
H: 2 mm + 0.5 ppm,     V: 5 mm + 0.5 ppm
25 Hz
Latency <20 msec
Average Time To Fixed RTK <7 sec
Cold Start <45 sec
Warm Start <20 sec
Re-acquisition <1.2 sec
Integrated UHF Radio 406 to 470 MHz
Integrated Cellular Modem
GSM/GPRS Quad Band
850/900/1800/1900 MHz
Integrated Bluetooth Class 2
Memory Storage 2 GB SD card minimum, removable
User Interface
Data Collector or PC
Serial Ports 1 x 5-pin Lemo, 1 x 8-pin Lemo
Waterproofing IP67
Certification CE, FCC Class B Part 15
Internal Battery 2 x Li-Ion, 5000 mAh, 7.4V
Current Drain 1.0 to 1.5A, 2.75A peak
External Power Input 9 to 18 VDC
Weight 1.3 kg
Dimensions 178 mm Dia. X 89.7 mm
Operating Temperature -20 to +65 degrees C
Storage Temperature -40 to +75 degrees C
Shock/Drop 2 m