Minelert started active development of the Lost Persons Detection (LPD) system in 2009 and have numerous successful implementations in the mining industry with proven reference sites. Minelert LPD system is a proximity (zoning) solution and is based on 2.45GHz technology that has been proven in search and rescue operations and many underground tunnel applications throughout the world. Minelert LPD system specifically addresses and overcomes the challenges found in RTLS technology within mining applications:

  • Reliable tracking information. Numerous Radio Frequency technologies (433MHz, 868MHz, etc.) were scientifically tested during development and it was proven that 2.45GHz has the best propagation characteristics for reliable and repeatable tracking accuracy.
  • Ease of installation and implementation. The reading range is fully adjustable from 1m up to 200m. No need for any RSSI site surveys. Tags are independent of any electrical subsystem and can be retrofitted to most target devices.
  • Superior battery life. Guaranteed battery life of over 6 years can be achieved on a 4-second beacon interval.
  • No complicated tag license agreements are required.
mining lost persons detection

Minelert LPD System Components

minelert lost persons detection system

The basic hardware and software components needed to successfully implement the Lost Persons Detection System can be explained by referring to the figure to the left, illustrating a typical system topology that consists out of the following major components:

  • Ethernet Backbone
  • Master Controller
  • Tag Controller
  • Active Tags
  • LPD Scanning Unit

Ethernet Backbone

A fundamental requirement for the success of the system is a stable and reliable industrial Ethernet Network. Read more about our network solutions here

Minelert Master Controller

Minelert Master Controller hosts the system database, applies the business logic, logs monitoring data, interacts with 3rd party T/A database, enables Web-based reporting, automatic report scheduling etc.


Reporting can be implemented as an aid to highlight, and possibly prevent, any zone movement that might have fatal consequences for an individual. These reports will indicate whether the individual has arrived and also departed from the allowed zone as defined by their gang allocations, with the exception of maintenance and emergency personnel. A report that flags individuals who have not yet returned to the lamp room and are unaccounted for, can also be implemented to complement current shaft clearance processes.

Reports are hosted on the Master Controller via the web interface for on-demand tag event searches or can be configured to be delivered as email attachments when specific tag event exception conditions are met.

Reports are generated by the Master Controller and can be accessed via Web Interface or sent as an E-mail attachment. These reports currently include, but are not limited to:

  • Asset/Employee zone movement
  • Asset/Employee zone transition movement
  • Asset/Employee activity within a zone
  • Asset workflow
  • Tag maintenance reports (missing tag, low battery etc)
  • Condition of Tag Controller reporting

Customized reports can be developed based on well-documented requirements.


Minelert Tracking Solution utilizes industry standards and can, therefore, be integrated with 3rd party T/A (Time and Attendance) or ERP systems seamlessly. Access to the SQL Server’s database specific tables or standards-based Messaging Broker Services can be used for integration.

The scope of Integration Requirements will be investigated and must be documented before implementation.

Minelert Tag Controller

Minelert Tag Controller is normally located in zones where tags (personnel, material cars, etc) need to be sensed. These zones might include transition areas like lamp rooms and station areas on each level. Other typical locations are waiting places, refuge chambers, level cross cuts, strike entries and more.

The Tag Controller transmits the 2.4GHz signal at less than 10mWatt, well below the regulators prescribed threshold of 100mWatt for 2.4GHz devices (as per ICASA specifications).

The latest generation of the Tag Controller now supports dual scanning interfaces that improve range accuracy. The reading range of each Tag Controller is also fully adjustable, allowing for precise measurement. The Tag Controller can easily be calibrated (attenuated) to scan tag zone areas from 1m and up to 200m* with medium gain antennae.

The Tag Controller also features sophisticated store-and-forward technology. In the event that the Tag Controller is disconnected from the network or any network connectivity fails, the Tag Controller will still persist all tracking events locally for up to 3 weeks*. Once the network is restored, all date- and time stamped events will be synchronized to Minelert Master Controller’s database for data consistency and reliability. The store-and-forward algorithm allows for more efficient network bandwidth utilization.

The Tag Controller connects to the network with its PoE IEEE 802.3 (Ethernet) or optional IEEE 802.11 (WiFi) interface.

minelert tag controller system

Minelert Active Tags

minelert active tag

Minelert Active Tag, which beacons within the 2.4GHz frequency band, is required for each person to be monitored and sensed by Minelert Tag Controller. Furthermore, it is also equipped with a 13.5MHz interface used to do near-field authentication as well as tag activation. The tags can include an optional temperature sensor capable of recording 256 temperature samples which can be used for the purpose of fatigue monitoring and environmental analysis.

By utilizing the latest ultra-low power technology, an expected battery life of over 6 years can be achieved on a 4-second beacon interval. A major benefit of tracking solutions is the ease of tag installation. Minelert Active Tag can be installed on any target device independent from its input power source, thus eliminating the need to cut wires and the potential for interference with the subsystem’s electrical circuit.

LPD Scan Unit

To specifically address all the aspects of locating lost personnel, a 125kHz interface with Close Proximity Detection (CPD) technology is now available on all new tags. The CPD interface enables very precise detection and can detect an obstructed tag within a meter accuracy. This feature, when used in conjunction with Minelert Lost Persons Detection (LPD) scan unit has been proven to be very successful in fall of ground scenarios, when used by a trained rescue team.

The mobile LPD scan unit has been specifically designed to aid the rescuer’s mission. The device is lightweight and can be strapped to the chest, freeing the rescue team member’s arms. An audible beeping sequence will indicate the proximity of the rescuer to the missing tag through an ergonomically designed earpiece. As the rescuer nears the targeted tag, the tone will increase in frequency and decrease if moving away. It also features a LCD display to select missing personnel and can remotely trigger an optional target buzzer to drastically reduce searching time.

minelert lost persons detection scan unit

Implementation of Minelert LPD System

Anglogold Ashanti

  • Mponeng Shaft: 8000 LPD tags, 1000 Material Car Monitoring tags
  • Moab Khatsong Shaft: 7400 LPD tags, 1000 Material Car Monitoring tags
  • Kopanang Shaft: 1000 Material Car Monitoring tags
  • Tau Tona Shaft: 1000 Material Car Monitoring tags

Harmony Gold

  • Doornkop Shaft: 1000 Material Car Monitoring tags
Case Studies

View our case studies page for info on Minelert deployment and success

Minelert offers a total solution for tracking logistics, asset tracking and lost person detection
Case Studies