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Kristen Heath
Feb 8, 2017, 12:55:27 PM2/8/17
to Motus Wildlife Tracking System
Hello all,
Can someone elaborate on the differences/drawbacks/advantages of Lotek vs. Sesorgnome receivers? I am trying to determine which would be best for our research (population connectivity of Snowy Plovers on the Southern Great Plains). Ideally, we only need to know presence/absence of the birds. Any insight would be very helpful.
Thank you!
Kristen
john brzustowski
Feb 9, 2017, 11:55:36 AM2/9/17
to motu...@googlegroups.com, sensor...@googlegroups.com
[apologies for cross-posting this reply, but not everyone is on both
lists]
Hi Kristen,
A few differences:
- power consumption is considerably higher for SGs; I'd guess by a
factor of at least 10 for a 3 antenna set-up. (Just a guess; I
haven't done any power consumption measurements on Lotek units.)
- Lotek receivers have probably 3 times the detection range with
default settings on the SG and the current signal processing
software. That is roughly a 27 x higher volume of space covered
by the Lotek receiver.
- an SG listens on all its antennas simultaneously; Lotek receivers
switch a single receiver among antennas. The former approach
provides more data for localization algorithms, but is one of the
main reasons SGs use more power. (The other is having much more
processing power onboard.)
- SGs have higher precision timekeeping; Lotek receivers have a
simpler "drift then jump" model for sync'ing to GPS time, rather
than a slewing model which continually adjusts an internal estimate
of clock frequency. This makes SG timestamps potentially more
useful in multi-station localization work.
- SGs record carrier frequency offset for each tag detection; this can
be used to estimate a tag's ambient temperature, provided you've
done some calibration work. This applies to both beeper and coded
ID tags, and does not require anything special on the tag side.
- SGs can store much more data (32 GB on a micro SD card, and more if you
attach a USB memory stick). However they also record more information,
and more noise, so the information density in the data is considerably
lower.
- SGs can be attached to a network via wired, WiFi, or USB cellular modem,
and send live detections to a server.
- SGs can be programmed to listen to multiple kinds of tags at the same
time.
- system costs are lower for the SG, but overall deployment costs
might not be, given the additional power set-up required. You can
build your own SG, or purchase a warrantied unit from compudata.ca
- SGs should be able to run unattended for longer, given the larger
storage. We have 3 units on Sable Island, 300 km east of Halifax,
which have run on solar power without a reboot for 1.5 to 2 + years.
They've been visited every 6 to 8 months for a data download. This
is unusual, and people often don't provide sufficient power, which
leads to more frequent restarts, and sometimes outages.
- The SG is an open-source modular system built from off-the-shelf
components, and is under continuous development. It requires more
learning by end users, and has more ways to fail.
- Lotek receivers are proprietary, but very well-engineered unitary
systems.
- data from both Lotek and SG receivers are handled by motus.org in as
uniform a manner as possible, given the differences between what the
receivers record.
I hope that helps.
John B.
lists]
Hi Kristen,
- power consumption is considerably higher for SGs; I'd guess by a
factor of at least 10 for a 3 antenna set-up. (Just a guess; I
haven't done any power consumption measurements on Lotek units.)
- Lotek receivers have probably 3 times the detection range with
default settings on the SG and the current signal processing
software. That is roughly a 27 x higher volume of space covered
by the Lotek receiver.
- an SG listens on all its antennas simultaneously; Lotek receivers
switch a single receiver among antennas. The former approach
provides more data for localization algorithms, but is one of the
main reasons SGs use more power. (The other is having much more
processing power onboard.)
- SGs have higher precision timekeeping; Lotek receivers have a
simpler "drift then jump" model for sync'ing to GPS time, rather
than a slewing model which continually adjusts an internal estimate
of clock frequency. This makes SG timestamps potentially more
useful in multi-station localization work.
- SGs record carrier frequency offset for each tag detection; this can
be used to estimate a tag's ambient temperature, provided you've
done some calibration work. This applies to both beeper and coded
ID tags, and does not require anything special on the tag side.
- SGs can store much more data (32 GB on a micro SD card, and more if you
attach a USB memory stick). However they also record more information,
and more noise, so the information density in the data is considerably
lower.
- SGs can be attached to a network via wired, WiFi, or USB cellular modem,
and send live detections to a server.
- SGs can be programmed to listen to multiple kinds of tags at the same
time.
- system costs are lower for the SG, but overall deployment costs
might not be, given the additional power set-up required. You can
build your own SG, or purchase a warrantied unit from compudata.ca
- SGs should be able to run unattended for longer, given the larger
storage. We have 3 units on Sable Island, 300 km east of Halifax,
which have run on solar power without a reboot for 1.5 to 2 + years.
They've been visited every 6 to 8 months for a data download. This
is unusual, and people often don't provide sufficient power, which
leads to more frequent restarts, and sometimes outages.
- The SG is an open-source modular system built from off-the-shelf
components, and is under continuous development. It requires more
learning by end users, and has more ways to fail.
- Lotek receivers are proprietary, but very well-engineered unitary
systems.
- data from both Lotek and SG receivers are handled by motus.org in as
uniform a manner as possible, given the differences between what the
receivers record.
I hope that helps.
John B.
Kristen Heath
Feb 10, 2017, 5:41:36 PM2/10/17
to Motus Wildlife Tracking System
John,
Kristen Heath
Graduate Research Assistant
Department of Natural Resources Management
Texas Tech University
anom...@gmail.com
Mar 1, 2017, 8:22:25 AM3/1/17
to sensorgnomads, motu...@googlegroups.com, jbrz...@fastmail.fm
Hi Kristen,
Ask also Arne Anderson of Lund University. They worked already a long(er) time with the DataSika's for NanoTags and are starting this year with SensorGnomes.
René
Op donderdag 9 februari 2017 17:55:36 UTC+1 schreef john brzustowski:
Op donderdag 9 februari 2017 17:55:36 UTC+1 schreef john brzustowski:
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