Testing for interference before station install
Laney White
Bart Noort
If we expect interference (for instance with antenna’s nearby or solarpanels nearby) we do a check with an SDR receiver (like the funcube) in combination with software like SDRconsole or SDRSharp, but of course that is only a check for the situation at that moment.
I think you have to consider two types of interference;
- masquerading / saturating interference (which will mask your tags with noise so the receiver can not find tags in the noise) the noise might be permanent.
- And damaging interference which might even damage your equipment.
I had a location with a church radio (on an illegal frequency) but it was very close to our tags frequency, and tags will be masqueraded and be undetectable: https://share.icloud.com/photos/0a6ovHf2q33luPubiosPGBbnQ
But that will not damage our equipment (it was far away) and will be only a problem for a short period a week.
And we had a location where there where solar panels installed close by (<100meter) which cause enormous interference only during daytime (I have a long period graph somewhere showing day/night exactly)
Also we had a 4G/3G/5G tower close at a location causing trouble and even false detections, and shielding the box with funcubes helped a bit over there.
I don’t like to install antenna’s close to marine radio sites, I am afraid it will damage the receivers.
Military communications is probably only short messages during training activities, and the rest of the days nothing.
Bart
Noort, Bart
If we expect interference (for instance with antenna’s nearby or solarpanels nearby) we do a check with an SDR receiver (like the funcube) in combination with software like SDRconsole or SDRSharp, but of course that is only a check for the situation at that moment.
I think you have to consider two types of interference;
- masquerading / saturating interference (which will mask your tags with noise so the receiver can not find tags in the noise) the noise might be permanent.
- And damaging interference which might even damage your equipment.
I had a location with a church radio (on an illegal frequency) but it was very close to our tags frequency, and tags will be masqueraded and be undetectable: https://share.icloud.com/photos/0a6ovHf2q33luPubiosPGBbnQ
But that will not damage our equipment (it was far away) and will be only a problem for a short period a week.
And we had a location where there where solar panels installed close by (<100meter) which cause enormous interference only during daytime (I have a long period graph somewhere showing day/night exactly)
Also we had a 4G/3G/5G tower close at a location causing trouble and even false detections, and shielding the box with funcubes helped a bit over there.
I don’t like to install antenna’s close to marine radio sites, I am afraid it will damage the receivers.
Military communications is probably only short messages during training activities, and the rest of the days nothing.
Bart
--
The Motus Wildlife Tracking System (Motus) is an international collaborative research network that uses coordinated automated radio telemetry to facilitate research and education on the ecology and conservation of migratory animals. Motus is a program of Birds
Canada in partnership with collaborating researchers and organizations. Learn more at
https://motus.org
---
You received this message because you are subscribed to the Google Groups "Motus Wildlife Tracking System" group.
To unsubscribe from this group and stop receiving emails from it, send an email to
motus-wts+...@googlegroups.com.
To view this discussion on the web visit
https://groups.google.com/d/msgid/motus-wts/f8e13fb7-0762-4325-84b8-8287b3315ac8n%40googlegroups.com.
Pat Lorch
On Nov 7, 2022, at 4:08 PM, Laney White <lmwh...@gmail.com> wrote:
Hi all,
--
William Blake
Hi Laney,
Glad to see that you are taking the ‘bull by the horns’, so to speak, and that you are interested in determining interference issues at potential Motus sites. As you already mentioned, there’s no single protocol now, but to add on to the great information Bart and Pat already provided, I would add that:
- If you happen to own a handheld receiver (preferably a Lotek handheld SRX800 type), it is a great idea to spend some time “listening” for radio interference with it, at the spot you plan to potentially install Motus antennas. The Lotek 166MHz frequency is more prone to detecting “false positives” than 434MHz. If you bring a Lotek handheld during your site visits, you are able to listen for radio noise/static in all directions to avoid pointing your future Motus antennas in the direction where the interference is the worst. You might also start picking-up false positive tag IDs (they will show up on the LCD display screen), which would indicate mis-interpretation of interference to a specific tag ID.
- Once you select a site, I would also encourage you (and anyone) to plug-in a Sensorstation or Sensorgnome at the potential install location, preferably with an antenna loosely connected to the top of the mast, so that you can spin it in all directioons, and connect your laptop to the Motus computer SG Interface. While you slowly turn the antenna in different directions over the course of a few minutes. If there’s any interference, youo should start seeing hits that will appear in the SG Interface display box.
- I think along with solar panels and communication towers, a huge issue for interference is electric power lines in the vicinity of a Motus station. I try to install at sites away from power lines.
A few other points, if you’re still reading:
- As Bart already mentioned, any test you conduct will only represent a small instance of time during which you are at the potential site, so you will not be able to gauge whether interference varies over time, but better than not testing at all.
- At this time, Motus stations with an antenna suffering lots of false positive detections cannot be trusted and unfortunately most researchers will filter these Motus stations out of their analyses. So thanks for trying to minimize interference 😊
- Also, in cases where people pay for modem connectivity and suffer from large amounts of false detections at an antenna, it can increase your modem data fees, up to several hundreds of dollars per month.
Sorry for the long response! Good luck!
William
****************************************
William Blake
Avian Biologist - IWC Motus Coordinator
MPG Ranch
wbl...@mpgranch.com
website: http://www.mpgranch.com
To view this discussion on the web visit https://groups.google.com/d/msgid/motus-wts/AM9PR01MB7171B2CEF96313338AAD9E45E53F9%40AM9PR01MB7171.eurprd01.prod.exchangelabs.com.
Laney White
To view this discussion on the web visit https://groups.google.com/d/msgid/motus-wts/PH0PR16MB421588DEC50ABB9C1694118EAF059%40PH0PR16MB4215.namprd16.prod.outlook.com.
Pat Lorch
On Nov 14, 2022, at 3:42 PM, Laney White <lmwh...@gmail.com> wrote:
To view this discussion on the web visit https://groups.google.com/d/msgid/motus-wts/CAE1D5hdAHtyt77ECbH-xgsYL%2BDxU1-ytr1CnFcGS0xSDc9Qeqw%40mail.gmail.com.