GPS tracking can provide detailed spatial and temporal data on mustelid movements with higher accuracy than VHF tracking, but conventional GPS collars are too large and expensive for many mustelid species. Recent developments include a low-cost GPS-GSM transmitter developed for otter tracking, as well as even smaller micro transmitters. However, battery life remains a limitation, and non-invasive tracking methods should also be explored.
2. Wish to follow mustelids 24/7
๏ง Conventional technique is
VHF tracking with collar or
implant (e.g. otters)
๏ง Lot of disadvantages: e.g. low
accuracy of positioning, need
of many man hours, need of
lots of fuel for car or boat.
3. Development of GPS tags
For more than 10 years GPS tags have been used for
wildlife studies
Reintroduced lions in Addo Elephant Park (SA)Photo: Addy de Jongh
4. Why use GPS for studying animals?
# GPS is for detailed spatial and temporal reconstruction of short-range movements
# VHF transmitters are for short-range localization of animals
# Satellite transmitters based on Argos for long-range movements (lower spatial resolution)
# GLS (geolocators): very small tags for recording movements over long distances
Note! Nowadays also other and mixed systems available, like: Proximity sensors, Mote
networks, RFID, Magneto-inductive tracking (e.g. underground animals), GPS Argos, GPS
Iridium, GPS RF, GPS GSM/CDMA
5. What is GPS?
It is not:It is:
Global Positioning System
Currently 32 Block II/IIA/IIR/IIR-M satellites
6. Accuracy of GPS
Accuracy of GPS can be 3 โ 20 meter
Increase of accuracy possible with Satellite-based augmentation systems
(SBAS):
Positional dilution of precision
EGNOS for Europe
7. Not only GPS!
The 3 major global positioning systems are:
1. USA: NAVSTAR known as the Global Positioning System GPS
2. Russia: Global'naya Navigatsionnaya Sputnikovaya Sistema:
GLONASS
3. European Union: GALILEO (not finished)
Galileo will have accuracy
of 20 โ 100 cm !
These three positioning systems are called together the
Global Navigation Satellite System or GNSS
8. How to get the GPS data?
1. Logging and retrieval of GPS tag later on;
2. Receiving data over a wireless link (e.g. VHF, UHF, bluetooth) manually or
automatically with receiving stations (e.g. near a waterhole);
3. Sending data to Argos satellites and receiving data by e-mail;
4. Sending data with Iridium or Globalstar networks and receiving by e-mail
SMS and/or internet;
5. Sending data with cellular networks (GSM/CDMA) and receiving by e-mail
SMS and/or internet;
BATTERY LIFE = MAIN LIMITATION OF GPS TAGS
1. The GPS receivers inside the devices use a lot of power;
2. When Argos, Iridium or GSM/CDMA modems are used for sending
data even more power consumption
MOST GPS GSM DEVICES ARE LARGE
BECAUSE OF LARGE BATTERIES.
9. GPS tracking of mustelids
Until some years ago GPS transmitters have only been used in large
carnivores. Recently they have also been used in studies on the following
large โ medium
sized Mustelid
species:
Fisher -- Martes pennantiWolverine โ Gulo gulo
Badger โ Meles melesOtter โ Lutra lutra
10. GPS GSM collars
In most mustelids collars will fit properly
Otters need a light weight harness, because of their
streamlined body โwithout a neckโ.
Disadvantage: most available systems are too large and
expensive: about โฌ 3.000 โ 4.000 euro / collar
GPS antenne
GSM + GPS
12. Development low cost
GPS GSM transmitters
2009: Dutch Otterstation
Foundation developed
own system based on Telit
GE863 combi GPS GSM
modem
Advantages:
๏ง Low cost (only โฌ 800,- !!!!)
๏ง Programming with open
source python
๏ง Sleep/wake up function
๏ง Small, light weight
16. Conclusion
Good results, robust system, energy consumption still too high
With some adaptation system can work for other and smaller mammals:
Necessary smaller module, less power consumption
17. New developments
1. Micro Telitracker:
๏ง Telit GE865 - GSM
๏ง uBlox NEO 5Q โ (A-)GPS
๏ง Atmega32u2 โ MCU
๏ง SIM/uSD kaart combi
2. Other approach:
Post-processing of raw GPS
signals. Only 200 millisecond
necessary for GPS fix.
Processing of GPS signal on
server.
18. Latest development
The only 25 x 25 mm
Atto GPS GSM module:
Origin GPS + Telit GSM +
Bosch accelerometer + SIM
on Chip + STM32 ยตC
25 mm
25mm
Test of Atto GPS GSM during trip
back from Portugal summer 2012
With 12 GPS fixes/day and 1 data
transmission/2 hrs with a 2500 mAh
battery the Atto can run for almost 200
days.
With less GPS fixes and only 1 data
transmission/day this can be much longer.
19. Welfare issues
Trapping and tagging animals is invasive. Gives stress.
Is it possible to use other, non-invasive methods?
Licensing is necessary.
Goal of radio tracking research should give a clear benefit for the
conservation of the species.
Success can only be there after thorough preparation.