SR-72 Unmanned balloon popper
If the balloon is transmitting…
Where are the Hamfags?
Don't need much.
PORTABLE J-POLE/SLIM JIM
https://www.amsat.org/amateur-radio-on-the-iss/
Need some hams with more experience than me.
But I'm sure some are at least listening to it. Curious about what freqs it's using tho.
Little info on wether balloons
o c e a n systems d i v i s i o n
SPECIFICATIONS
TRANSMITTERS
Nominal Frequency: 403 MHz
Tuning Range: 400-406 MHz
Output Power (Nominal): 240 mW
Modulation: FM
Nominal Frequency: 1680 MHz
Tuning Range: 1680-1700 MHz
Output Power (Nominal): 300 mW
Modulation: FM
DATA TRANSMISSION
Type: Digital Bi-Phase
Transmission Rate: 400 Baud
Subcarrier (Loran) 100 kHz
DATA CHANNELS
Pressure, Temperature, Humidity plus 4 spare channels.
SAMPLING RATE
All parameters once per second. Each data set
transmitted twice for added reliability.
POWER SOURCE
Single water-activated battery.
SENSOR CALIBRATION
Polynomial coefficients resident in sonde EEPROM are
transmitted continuously in digital data-stream.
PRESSURE SENSOR
Type: Continuously variable
capacitance aneroid
Measuring Range: 1080 mb to 3 mb
Accuracy: ±0.5 mb (rms)
Resolution: 0.1 mb
TEMPERATURE SENSOR
Type: Thin rod thermistor
Range: -90ºC to +60ºC
Accuracy: ±0.2ºC (rms)
Resolution: 0.1ºC
HUMIDITY SENSOR
Type: Carbon type
Range: 5 to 100% RH;
+40ºC to -50ºC
Accuracy: 2% RH (rms)
Resolution: 1% RH
DIMENSIONS
144 x 102 x 193 (mm)
WEIGHT
300 grams (including battery, dereeler, & cord)
MODEL
1540 1680 MHz, P, T, U
1543 403 MHz, Loran-C/P, T, U
1547 403 MHz, P, T, U
1548 403 MHz, GPS
Sensor information is transmitted in
digital form at a 400 baud rate. The
prior meteorological sampling is
attached to the end of each new frame
of data. If a frame of data is lost in
transmission, the W-9000 system
replaces the missing data using this
redundancy feature.
The Mark II MICROSONDE series uses
two methods to address the problem of
radio frequency interference in the
meteorological band. First, multi-stage
transmitters at both 403 MHz and
1680 MHz frequencies provide highly
stable signals over the entire range of
operating temperatures. For critical
applications, high stability transmitters
are available. Secondly, the Mark II serial
number is transmitted continuously in
the digital data stream.This feature
allows the W-9000 synthesized receiver
to lock-on to the Mark II data
transmission throughout the flight.
PRESSURE MEASUREMENT
The ZEEMET Mark II series of
radiosondes features a capacitive
aneroid for continuous pressure
measurement. Precise manufacturing and
calibration processes minimize effects
due to temperature, hysteresis, and drift.
Calibration information is encoded in
the radiosonde EEPROM and
transmitted continuously.
TEMPERATURE MEASUREMENT
A thin ACCU-LOK fast response rod
thermistor is employed to measure
temperature. The thermistor lock-in
resistance value is part of the
radiosonde data stream, eliminating
the need for preflight baselining.
HUMIDITY MEASUREMENT
A small ACCU-LOK fast response
carbon hygristor is utilized to measure
to optimize the accuracy of humidity
measurement. Each hygristor is
permanently installed in the radiosonde;
a protective vial is removed prior to
launch to expose the sensor. Here again
the lock-in values are included as part of
the radiosonde data stream.
WINDS
The Loran-C Mark II MICROSONDE
retransmits radionavigation signals to
the W-9000 System. The W-9000
System then processes these signals into
winds data.These Mark II
MICROSONDES incorporate a low
noise integrated circuit receiver tuned
to the respective frequencies to amplify
signals before applying them to the
modulator/transmitter. Receiver gain is
designed to pick up the weakest signal
of Loran-C networks so that the sonde
can be flown virtually anywhere suitable
coverage is available.
The GPS Mark II MICROSONDE
includes a full code correlating, all-in-view
GPS receiver and antenna.The GPS
receiver processes signals from all
visible satellites and is integrated into
the radiosonde electronics. Raw GPS
data (LOS) from the receiver is encoded
and added to the serial PTU data.The
sum of these two data streams is then
sent as a single digital transmission
within the 400-406 MHz bandwidth.The
W-9000 system receives, filters, decodes
and processes these signals into
accurate winds data.
DEREELER
The Mark II has an internal automatic
dereeler (with 30 meters of cord) to
facilitate launch in high winds, on board
ship, or with only one operator. A
centrifugal clutch governs the payout
rate of the cord.The operator needs
https://forums.radioreference.com/threads/weather-balloon-frequencies.47856/#post-358070
HAMS are looking at the balloon
Some want to skip the signal off it like a moon bounce. kek
Hams should be interested…
This shot of the 'errant' "weather balloon" clearly shows a multi frequency beam steered array, capable of focusing on a number of positions at will. It is unlikely the system is a RADAR array, as such direct transmission would be construed as a prime provocation for a hostile conflict. Its a listening array. RX only.
Satellites are not capable of monitoring low level terrestrial based transmissions. That is why this balloon is being used.
Expressing a personal opinion– a stupid move. Your opinion may differ,
OTOH, the array is not for 'weather' as such narrow antenna beams and steering ability is not useful in weather measurements.
IF this occurs again hams are encouraged to use 2M and 430 MHz gear, usually for sat comms, to bounce off the balloon /array as a passive repeater. Use your hand held Yagis. This should provide contacts from 800-1500 miles via reflection.