RS80 radiosonde decoding

[red_dot@email.it]

Recently have been made available on ebay surplus stock of RS80
radiosonde.
They have very sensitive and accurate sensor for Pressure, temperature
and Humidity measurement up to 30 Km. I' m just asking some hints or
help to decode the signal transmitted from the sonde to the ground.
Please note that all over the world every day are lunched hundreds of
sondes, using the same signal coding technique.

So, if anyone is interested, we could start a cooperative work in
order to find the best way to decode RS80 signals, both from
meteorological station and by self-lunched balloon (or rocket !!)

Basically, the 403 Mhz radio signal is modulated in the range 7 to 10
KHz, and six "channel" are sent in sequence (2 as low/hight reference,
4 for physical quantity)The first channel is the highest frequency,
and mark the start of the "packet", which last about 1.5 sec.

Please send copy also by mail (I'm not used to these NG !!)

Red_fab

 

[Si Ballenger]

On 19 Mar 2004 07:22:13 -0800, red_dot@email.it
(red_dot@email.it) wrote:

Recently have been made available on ebay surplus stock of RS80
radiosonde.
They have very sensitive and accurate sensor for Pressure, temperature
and Humidity measurement up to 30 Km. I' m just asking some hints or
help to decode the signal transmitted from the sonde to the ground.
Please note that all over the world every day are lunched hundreds of
sondes, using the same signal coding technique.

So, if anyone is interested, we could start a cooperative work in
order to find the best way to decode RS80 signals, both from
meteorological station and by self-lunched balloon (or rocket !!)

Basically, the 403 Mhz radio signal is modulated in the range 7 to 10
KHz, and six "channel" are sent in sequence (2 as low/hight reference,
4 for physical quantity)The first channel is the highest frequency,
and mark the start of the "packet", which last about 1.5 sec.

Please send copy also by mail (I'm not used to these NG !!)

Red_fab

A google search seems to turn up a lot of sites with info.

 

[Steve Nosko]

There is also data available from the manufacturer, on the web. I
downloaded it not so long ago.

--
Steve N, K,9;d, c. i My email has no u's.
"Si Ballenger" <shb*NO*SPAM*@comporium.net> wrote in message
news:405b1483.1955822053@news.comporium.net...

On 19 Mar 2004 07:22:13 -0800, red_dot@email.it
(red_dot@email.it) wrote:

Recently have been made available on ebay surplus stock of RS80
radiosonde.
They have very sensitive and accurate sensor for Pressure, temperature
and Humidity measurement up to 30 Km. I' m just asking some hints or
help to decode the signal transmitted from the sonde to the ground.
Please note that all over the world every day are lunched hundreds of
sondes, using the same signal coding technique.

So, if anyone is interested, we could start a cooperative work in
order to find the best way to decode RS80 signals, both from
meteorological station and by self-lunched balloon (or rocket !!)

Basically, the 403 Mhz radio signal is modulated in the range 7 to 10
KHz, and six "channel" are sent in sequence (2 as low/hight reference,
4 for physical quantity)The first channel is the highest frequency,
and mark the start of the "packet", which last about 1.5 sec.

Please send copy also by mail (I'm not used to these NG !!)

Red_fab

A google search seems to turn up a lot of sites with info.

 

[Ian Stirling]

In sci.electronics.misc Si Ballenger <shb*NO*SPAM*@comporium.net> wrote:

On 19 Mar 2004 07:22:13 -0800, red_dot@email.it
(red_dot@email.it) wrote:

Recently have been made available on ebay surplus stock of RS80
radiosonde.

A google search seems to turn up a lot of sites with info.

I couldn't find anywhere giving "this is the format of the data",
"this is the modulation scheme".
I assume it outputs psuedoranges, which won't directly get you
position (without significant work and currentish orbits) but can
fairly easily be used with another GPS to get differential position.

 

[red_dot@email.it]

"Ian Stirling" <root@mauve.demon.co.uk> wrote in message
news:tF37c.22297$h44.2747510@stones.force9.net...
In sci.electronics.misc Si Ballenger <shb*NO*SPAM*@comporium.net> wrote:
On 19 Mar 2004 07:22:13 -0800, red_dot@email.it
(red_dot@email.it) wrote:

Recently have been made available on ebay surplus stock of RS80
radiosonde.

A google search seems to turn up a lot of sites with info.

I couldn't find anywhere giving "this is the format of the data",
"this is the modulation scheme".

Have a look to http://www.qsl.net/dl3gaz/decoder/convert.pdf
(for Pressure, Temperature and Humidity decoding)

 

[Ian Stirling]

In sci.electronics.misc red_dot@email.it <red_dot@email.it> wrote:

"Ian Stirling" <root@mauve.demon.co.uk> wrote in message
news:tF37c.22297$h44.2747510@stones.force9.net...
In sci.electronics.misc Si Ballenger <shb*NO*SPAM*@comporium.net> wrote:
On 19 Mar 2004 07:22:13 -0800, red_dot@email.it
(red_dot@email.it) wrote:

Recently have been made available on ebay surplus stock of RS80
radiosonde.

A google search seems to turn up a lot of sites with info.

I couldn't find anywhere giving "this is the format of the data",
"this is the modulation scheme".

Have a look to http://www.qsl.net/dl3gaz/decoder/convert.pdf
(for Pressure, Temperature and Humidity decoding)

From what I can tell this is not a similar format.
I believe the output of the RS80 is completely digital.

 

[red_dot@email.it]

Ian Stirling <root@mauve.demon.co.uk> wrote in message news:<tF37c.22297$h44.2747510@stones.force9.net>...

In sci.electronics.misc Si Ballenger <shb*NO*SPAM*@comporium.net> wrote:
On 19 Mar 2004 07:22:13 -0800, red_dot@email.it
(red_dot@email.it) wrote:

Recently have been made available on ebay surplus stock of RS80
radiosonde.

A google search seems to turn up a lot of sites with info.

I couldn't find anywhere giving "this is the format of the data",
"this is the modulation scheme".
I assume it outputs psuedoranges, which won't directly get you
position (without significant work and currentish orbits) but can
fairly easily be used with another GPS to get differential position.

You can find some (not very positive) note on GPS onboard RS80 at
http://www.frars.org.uk/cgi-bin/render.pl?pageid=1257

 

[Dan Major]

red_dot@email.it (red_dot@email.it) wrote in
news:24167ac2.0403190722.2aba0886@posting.google.com:

Recently have been made available on ebay surplus stock of RS80
radiosonde.

These are RS80-15N Vaisala radiosondes. They use the old OMEGA navaid
system which I *believe* has been turned off. There are two problems with
using these out-of-the-box (besides the OMEGA problem). 1) propriatery
encoding scheme - good luck finding out what it is! 2) the units come with
a paper calibration tape that is run through a reader prior to launch. If
you don't have the reader/interface/software you have NO idea what the
response curve of the sensors is, and each one IS different. There's a
company that sells an interface that repalces the vaisala sensors and lets
you input several channels of analog data. Or you can pull off the vaisala
sesnors and put a 555 oscillator on and use as a tracking beacon.

Sooner dot boomer at gbronline dot com

 

[SB]

But really....do you need to have a temp reading to the 4th decimal place??

the decoding scheme is on the net....HOWEVER, you still must get it out of
that 403Mhz FSK transmission...

"Dan Major" <nospam@this.address> wrote in message
news:Xns94B55873AAEsoonerboomergbronlin@68.12.19.6...

red_dot@email.it (red_dot@email.it) wrote in
news:24167ac2.0403190722.2aba0886@posting.google.com:

Recently have been made available on ebay surplus stock of RS80
radiosonde.

These are RS80-15N Vaisala radiosondes. They use the old OMEGA navaid
system which I *believe* has been turned off. There are two problems with
using these out-of-the-box (besides the OMEGA problem). 1) propriatery
encoding scheme - good luck finding out what it is! 2) the units come
with
a paper calibration tape that is run through a reader prior to launch. If
you don't have the reader/interface/software you have NO idea what the
response curve of the sensors is, and each one IS different. There's a
company that sells an interface that repalces the vaisala sensors and lets
you input several channels of analog data. Or you can pull off the
vaisala
sesnors and put a 555 oscillator on and use as a tracking beacon.

Sooner dot boomer at gbronline dot com

 

[Dan Major]

"SB" <chicbears@hotmail.com> wrote in
news:gY18c.14537$WxP.3204@news01.bloor.is.net.cable.rogers.com:

But really....do you need to have a temp reading to the 4th decimal
place??

The vaisala sonde mentioned does not provide that degree of resolution.

the decoding scheme is on the net....HOWEVER, you still must get it
out of that 403Mhz FSK transmission...

Please provide a URL for the decoding scheme. The sondes are tunable from

around 400 to around 416 MHz narrow-band FM. They do not use Frequency
Shift Keying modulation.

 

[SB]

Here's what I found for the code itself:
http://apollo.lsc.vsc.edu/classes/met131/raob.html

Here's some German guys home brew kit on decoding it....haven't read the
entire page to see how it works:
http://www.qsl.net/dl3gaz/decoder/

I work for Environment Canada and have access to all sorts of "bad" sondes
(they just didn't pass the preflight sensor checks)....some of these have
the GPS capability....

But it's getting around the RF that I'm unsure of.
Haven't looked for a cct site yet!



"Dan Major" <nospam@this.address> wrote in message
news:Xns94B5AAA7BDF4Fsoonerboomergbronlin@68.12.19.6...

"SB" <chicbears@hotmail.com> wrote in
news:gY18c.14537$WxP.3204@news01.bloor.is.net.cable.rogers.com:

But really....do you need to have a temp reading to the 4th decimal
place??

The vaisala sonde mentioned does not provide that degree of resolution.


the decoding scheme is on the net....HOWEVER, you still must get it
out of that 403Mhz FSK transmission...

Please provide a URL for the decoding scheme. The sondes are tunable from
around 400 to around 416 MHz narrow-band FM. They do not use Frequency
Shift Keying modulation.

 

[Dan Major]

I work for Environment Canada and have access to all sorts of "bad"
sondes (they just didn't pass the preflight sensor checks)....some of
these have the GPS capability....

But it's getting around the RF that I'm unsure of.
Haven't looked for a cct site yet!

I used to work for the National Severe Storms Laboratory in Norman, Ok. We
had samples of just about every type os sonde ever made. The vaisala were
very common because of government (National Weather Service) contracts. I
used to have a manual that was made up by reverse engineering the sondes
and the receiving equipment. I don't know where it is, but with some
effort I might be able to get a copy. The newest sondes (and these are
quite old) are tracked by the home station, via a multiplexed antenna
array, and do not tracked by the location of the sonde. Special
application (vaisala) sondes like drop sondes for hurricane work, or
research projects, DO use gps now, but it's only a gps receiver, not a full
gps engine. The sondes the Natn'l Weather Service use are all 1680MHz.
There's a Canadian company that makes good RF modules, http://www.abacom-
tech.com/home.htm . We wanted to use commercial off-the-shelf modules for
a research project, but couldn't find any in the 400-406 MHz range.
Abacom's stuff is 413MHz (or in other bands), and because they use SAW
technology, they couldn't easily change frequency.

 

[Ian Stirling]

In sci.electronics.misc SB <chicbears@hotmail.com> wrote:

Here's what I found for the code itself:
http://apollo.lsc.vsc.edu/classes/met131/raob.html

This looks like how to decode the output from a 'proper' decoder.

Here's some German guys home brew kit on decoding it....haven't read the
entire page to see how it works:
http://www.qsl.net/dl3gaz/decoder/

This is for the non-GPS ones I think.
The GPS ones transmit at least the GPS signal in digital format.
I suspect they also transmit the old format, but am not sure.

I work for Environment Canada and have access to all sorts of "bad" sondes
(they just didn't pass the preflight sensor checks)....some of these have
the GPS capability....

But it's getting around the RF that I'm unsure of.
Haven't looked for a cct site yet!

 

[Ian Stirling]

In sci.electronics.misc Dan Major <nospam@this.address> wrote:

I work for Environment Canada and have access to all sorts of "bad"
sondes (they just didn't pass the preflight sensor checks)....some of
these have the GPS capability....
snip
I used to work for the National Severe Storms Laboratory in Norman, Ok. We
had samples of just about every type os sonde ever made. The vaisala were
snip
research projects, DO use gps now, but it's only a gps receiver, not a full
gps engine. The sondes the Natn'l Weather Service use are all 1680MHz.

From what I gather, the RS80 GPS probably outputs psuedoranges.
This is not the same as positions, but is the relative time delays to
each satellite.
Combined with a knowledge of the satellite orbits (most normal GPS recievers
can tell you this) this will give you a position.
Numerically, this'll probably look like a satellite number (5 bits), and then
a several bit (14?) psuedorange.

You cannot get position from this signal directly.
If you know the orbits of the sateelites and the approximate position
(+-10km?) of the sonde, then you can track movement accurately.
If you lose the signal for more than a very short time, you can't get
the movement right.

 

[red_dot@email.it]

Dan Major <nospam@this.address> wrote in message news:<Xns94B5BA84BE46Asoonerboomergbronlin@68.12.19.6>...

I used to have a manual that was made up by reverse engineering the sondes
and the receiving equipment. I don't know where it is, but with some
effort I might be able to get a copy.

It sounds VERY interesting !!!
Despite the fact that RS80-15N is quite old, the coding algorithm
for PTU is always the same, in order to keep compatibility with old
ground based equipment.

We wanted to use commercial off-the-shelf modules for
a research project, but couldn't find any in the 400-406 MHz range.
Abacom's stuff is 413MHz (or in other bands), and because they use SAW
technology, they couldn't easily change frequency.

Yes, we looked for modules, too, and we got same answer.
Anyway, you can receive the sonde with any radio scanner and a good
antenna.
I asked a friend to modify an amplifier and antenna used for hamradio
band
close to Vaisala one, and we got excelent results with a very cheap
equipment.

 

[red_dot@email.it]

"SB" <chicbears@hotmail.com> wrote in message news:<gY18c.14537$WxP.3204@news01.bloor.is.net.cable.rogers.com>...

But really....do you need to have a temp reading to the 4th decimal place??

No, but if you do not use calibration coefficients from tale, you get
meaningless values.

the decoding scheme is on the net....HOWEVER, you still must get it out of
that 403Mhz FSK transmission...

PTU data is not FSK encoded. It is transmitted as analog modulation in
the
7-10 Khz range
(or 0.7 - 1 KHz range for narrow band version, such as RS80-30x sonde)
Data from additional sensors, such as Ozonesonde, are trasmitted using
AFSK modulation, in the lower range (about 2000 Hz).
You can decode ozone signal using an old Bell 103 modem.

REd_dot

 

[Dan Major]

You cannot get position from this signal directly.
If you know the orbits of the sateelites and the approximate position
(+-10km?) of the sonde, then you can track movement accurately.
If you lose the signal for more than a very short time, you can't get
the movement right.

The satellite data are called ephemera, and I believe these are stored in
the GPS engine and then calculated-for-now using the time/date encoded in
the GPS transmission. I know the vaisala system had a "home-base" GPS
reciever. We had problems with some GSP-instrumented sondes that were
tethered below research packages because of severe swaying. I don't know
if it was because the GPS receiver in the sondes lost lock or of they
couldn't calculate the right data. When they regained lock there would be
skewed data for several seconds.



--
Sooner dot boomer at gbronline dot com

 

[Ian Stirling]

In sci.electronics.misc Dan Major <nospam@this.address> wrote:

You cannot get position from this signal directly.
If you know the orbits of the sateelites and the approximate position
(+-10km?) of the sonde, then you can track movement accurately.
If you lose the signal for more than a very short time, you can't get
the movement right.

The satellite data are called ephemera, and I believe these are stored in

I know, I used the phrase because I was very unsure of my spelling of
ephemeris. (?)

the GPS engine and then calculated-for-now using the time/date encoded in
the GPS transmission. I know the vaisala system had a "home-base" GPS

They are transmitted from the satellites.
There are two basic forms, a crude one that works for a few hours, or
a more accurate one that works for several weeks (?).
The date/time is transmitted every 6 seconds.

reciever. We had problems with some GSP-instrumented sondes that were
tethered below research packages because of severe swaying. I don't know
if it was because the GPS receiver in the sondes lost lock or of they
couldn't calculate the right data. When they regained lock there would be
skewed data for several seconds.

 

[SB]

Ok, but you then just have tones don't you? How do you decode the
tones....or did you decode them?

<red_dot@email.it> wrote in message
news:24167ac2.0403241007.72c78b2d@posting.google.com...

Dan Major <nospam@this.address> wrote in message
news:<Xns94B5BA84BE46Asoonerboomergbronlin@68.12.19.6>...

I used to have a manual that was made up by reverse engineering the
sondes
and the receiving equipment. I don't know where it is, but with some
effort I might be able to get a copy.

It sounds VERY interesting !!!
Despite the fact that RS80-15N is quite old, the coding algorithm
for PTU is always the same, in order to keep compatibility with old
ground based equipment.

We wanted to use commercial off-the-shelf modules for
a research project, but couldn't find any in the 400-406 MHz range.
Abacom's stuff is 413MHz (or in other bands), and because they use SAW
technology, they couldn't easily change frequency.

Yes, we looked for modules, too, and we got same answer.
Anyway, you can receive the sonde with any radio scanner and a good
antenna.
I asked a friend to modify an amplifier and antenna used for hamradio
band
close to Vaisala one, and we got excelent results with a very cheap
equipment.