This is part of my interest in weather, Cloud Sensors and Electronics/Radio.
Typical frequencies are 403 and 1680 MHz. These are typically lofted using a free balloon, but sometimes are dropped from aircraft using a parachute (Dropsonde). They can be tracked using a Pilot Balloon Theodolite or by means of an automatically following receiving antenna. For the Project Mogul balloon flights they also used the Direction Finder (Wiki) radio in a chase airplane that would fly below the balloon. This required a special balloon transmitter in the frequency range of the DF radio. The most modern radiosondes make use of GPS.
Very early balloon lifted weather instruments were essentially the same a ground based instruments such as drum recorders or smoked glass recorders. But starting with the availability of vacuum tubes (Wiki) in the early 1900s radio telemetry (Wiki) was used. There were numerous schemes of how to encode the weather data, typically barometric pressure, temperature and humidity, onto the radio frequency signal.
The idea here is to have meter faces all in the same plane and a contact driven by a clockwork, say once per minute. Then the clock dial can be divided up, for example: 0 to 15 seconds the temperature, 16 to 30 seconds the humidity and 31 to 59 seconds the barometric pressure. With a reference signal at the top of the minute. This is an unambiguous readout, but the clockwork motors are mechanical and so not as reliable as more modern electronic methods.
These sent Morse code (Wiki) messages. a big advantage is that a radio or telegraph operator can write down the data, but at a huge expense in the mechanism.
2287786 Automatic weather station, Diamond Harry, Jr Wilbur S Hinman, 1942-06-30 - does not require a specialized receiver
Radio Frequency Modulation
This had problems in that many things cause the frequency of an oscillator to change in addition to the parameter that was being measured.
NBS - Diamond & Hinman - Navy: Pressure Drive
For example see AMT-4B Modulator Fig 2 below and Figures 52 & 53 in the reference and patents 2283919 & 2689342 below. This system worked fine for a free weather balloon that is always rising. But. . . has a problem with what is supposed to be a constant altitude balloon where it goes up and down in cycles. That makes interpreting the data almost impossible. This caused problems for the project MOGUL balloon flights (Wiki).
The Invention and Development of the Radiosonde, with a Catalog of Upper-Atmospheric Telemetering Probes in the National Museum of American History, Smithsonian Institution, 2002 -
Harry Diamond (Wiki) - Hary Diamond Labs (Wiki) - a key part of the development of the proximity fuze. holds a number of patents including aircraft DF
The first generation were balloon carried radio transmitter sending barometric pressure (altitude), temperature and humidity back to a ground station. A Pilot Balloon (Pibal) theodolite would track the balloon by recording azimuth and elevation vs. time, which can be converted to a map of the balloon location and altitude. A fist step in making a weather map or forecast.
Later special radar sets (Rawinsonde) replaced the pibal theodolites. The first generation used the SCR-582 anti-aircraft RADAR (Wiki) sets and ML-307 reflectors (TM 750-5-3 pg 133). The latest units contain built-in GPS receivers.
This radiosonde was made by Space Data Corp.
Mfg p/n: 691-4005-02
Contract: F04606-89-C-1041 (year 1989)
Fig 1 SDC
Fig 3 Paper Tape and Humidity
sensor on lid.
250 to 1050 MB
Base station coefficients:
0 90 -60 -95 5 70
Carrier Freq. Mhz 403.500
Atmospheric Instrumentation Research
Fig 1 New in sealed bag
4907449 Meteorological data encoder for measuring atmospheric conditions, A.I.R., Inc., Mar 13, 1990, 73/170.28, 73/724, 374/170 -
4112753 Meteorological measuring apparatus, David B. Call, Sep 12, 1978, 73/170.28, 340/870.1 -
"A radiosonde is conformable for use either as a disposable sonde in which the device will ascend vertically to a predetermined altitude and when the balloon from which it is suspended bursts at a maximum altitude the sonde will automatically flip over and autogyrate at a reduced rate of descent back to earth; or may be used as a tethered radiosonde in which it is suspended from a tethered balloon in such a way as to be freely rotatable about a substantially horizontal axis. In either version, the sonde is characterized by a generally helicoidal propeller construction having thermistor-receiving end tips and whereby the propellers will impart sufficient spin or rotation to the sonde as to cause the desired degree of aspiration to provide accurate wet bulb psychometric measurements; and further the propeller construction is such as to permit freefall at a reduced controlled rate of speed without the assistance of a parachute."
NSN 6660-01-348-7451, ML-674(V)3/TMQ
See FM 6-16 Ch 6.6 Radiosondes for detailed description.
FM signal modulated by audio frequency switched by barometric pressure.
Fig 2 1680 MHz +20/- 10 MHz adj.
Vaisala RS80-67 radiosonde
Vaisala RD93 GPS Dropsonde (data sheet.pdf)
PS the photo on the data sheet shows both red tapes in place and the chute deployed, i.e. a fake photo.
9753183 Aircraft expendable instrument launch detector system, University Corp for Atmospheric Research (UCAR), 2015-03-03 - interesting citations & references
Airborne Vertical Atmospheric Profiling System (AVAPS)
UCAR/Intellectual Property and NCAR/SSSF have licensed Vaisala Inc. of Woburn, Massachusetts to build the NCAR GPS Dropsonde, as Vaisala model RD93.
This is a dropsonde (dropped from an aircraft) rather than a radiosonde that's lifted by a pilot balloon. In includes a built-in GPS receiver so no tracking is needed. A special receiver is used to capture both the weather data and GPS position.
Ships with six CR-2 lithium cells in series (>15 VDC) with a current draw of 235/1200 mA giving a 2 to 3 hour operating time.
In Fig 2 below note the two red tapes that are to be removed prior to launch. One allows removing the bottom cap and the other uncovers the square cone parachite. There is also a plug just next to the 4P4C RJ-11 socket that activated the battery when it's removed.
Fig 1 came in hermetic sealed bag. Marked:
0041 255 081
Fig 2 Label:
RD93 GPS Dropsonde
Serial Number: 004 255 081 (stick on label just line the label on bag)
Manf. Date: February 2001
Made in USA, VAaisala, Woburn, MA
Fig 2 Top cap removed showing pyramid (Square cone) shaped retarding chute
5149019 Balloon parachute, University Corp for Atmospheric Research (UCAR), 1991-09-30, -
Fig 4: 3" Launch Tube devices top to bottom:
T-347/SRT Buoy, Radio Transmitting - launched from submarine
Vaisala RD93 GPS Dropsonde - launched from airplane
SUS: Signal Underwater Sound - launched from airplane
Sippican Ocean Systems SSXBT Model ST-1 Bathythermograph -launched from submarine
7358862 Radiosonde system, radiosonde system receiver and signal processing method in a radiosonde receiver, Vaisala Oy, 2008-04-15 -400 MHz data down-link & separate position DL channel. A multi-channel receiver, uses DSP techniques so can receiver data from multiple soundes at the same time.
See FM 6-15, Chapt 6 Observation equipment, Section V, Rawinsonde System.
Designed for taking atmospheric soundings and thereby obtaining upper air meteorological data. This is accomplished by measuring the wind speed, wind direction, pressure, temperature, and humidity through out the vertical extent of the sounding.
Rawin set AN/GMD-1
Radiosonde recorder AN/TMQ-5
and associated equipment: TS-65 Freq Std, Baseline check set AN/GMM-1, Test Set TS-538, 10-kW power unit PE-75, Met Station Manual AN/TMQ-4
Many of the batteries used for Radiosondes are the type called a Reserve Battery (Wiki) since this type of battery has an extremely long shelf life. Other applications for reserve batteries are artillery shells and sonobuoys.
The BA-259 and BA-380 showed up on eBay in October 2017 from seller delawarelister. I expected the tin cans (Wiki) to be smaller than they turned out (5" dia x 6-1/4" tall) they are about the size of a coffee can.
Used with the AMT-4 radiosonde.
Do Not Open
Until Battery is to be
Battery, Water Activated
Colorado Springe, Colo.
BA-380/AMQ-9The AMQ-9 is listed as: Transponder Radiosonde; manufactured by VIZ Manufacturing Co.
MIL-R-55065A(3) NOT 1 Radiosonde Set AN/AMQ-9() (No SS Document)(Cust:ER)(Review:99)
Very similar to the VIZ MD-210 above.
Do Not Open
Until Battery is to be
Ray-O0Vac Division, Mfg/Contr
Meteorological Equipment Data Sheets
Lists equipment with the following designations:TM1-6625-407-14 Operator's Organizational, Direct Support, and General Support Maintenance manual, Frequency Standard TS-65C/FMQ-1 and TS-65D/FMQ-1, NSN 6625-00-649-4279, October 1973. - Tuning Fork audio generator with output frequencies of: 10, 20, 40, 60, 80, 100, 120, 140, 160, 180 and 190 Hz as negative going pulse to calibrate the AN/TMQ-5(*) recorder.
PMQ-1, -3, -4, -6
TMQ-3, -5, -19, -22
ML-4, -5, -7, 17, -24, -48, -51, -54, -64, -74, -77, -79, -102, -122, -132, -145, -155, -156, -157, -158, -159, 160, -161, -162, -180, -187, -188, -193, -214, -224, -247, -303, -305, -307, -312, -332, -333, -433, -462, -474, -475, -512, -513, -514, -536, -537, -541, -556, -566, -573, -577, -594, -605, -607, -1309
Olland radio meteorograph, NBS RP-1169, VOl 22, 1939 - is
mentioned in some of the patents.
Diamond-Hinman UHF Tx "Research Paper RP 1329" NBS Vol 25, Sep 1940) "An Improved Radiosonde and It's Performance".
Wallace and Tiernan
mainly did water Chlorination, but also patented may Aneriod
pressure gauges (Wiki).
Some of these were calibrated as altimeters.
Kollsman mainly made aircraft instruments, many of which made use of Aneriod pressure capsules.
Pressure switching, Diamond
Harry, Jr Wilbur
S Hinman, 1943-06-22 -
Determining upper air wind conditions by radio
direction finding, Diamond
W Dunmore, Jr
Wilbur S Hinman, Filed: 1938-12-22, Pub:
2689342 Pressure operated switching device, Goudy Paul R, Kollsman Instr Corp, Sep 14, 1954, 340/870.1, 200/83.00R, 200/81.5, 439/31, 340/870.13, 340/870.16 - uses two barometric elements with different pressure ranges to improve accuracy.
This is a 2 capsule version of the pressure drive system. I've colored the contacts on the Aneriod to make the switching more clear. In this application there's a relay and segment "D" to handle 2 capsules, but in the single capsule version there is neither segment D nor relay.
This is the design that has a problem when used with a constant level balloon.
The Pilot Balloon theodolite main function is to track a weather balloon in order to determine the wind direction and speed at the various elevations as the balloon rises. There are some problems such as when you can not see the balloon because of clouds or darkness (a small flashlight lamp + battery was tried as a solution, but I don't know how well it worked).
A solution to the problem was to use the SCR-584 RADAR (Wiki) that was already fielded in many war zones for pointing anti-aircraft guns. But RADAR can not track a balloon, it needs some type of reflector. The ML-307 was designed to reflect the 10 cm wavelength RADAR signals allowing it to automatically track a balloon as it rises. These Weather RADar WINd Targets were called RAWINs.
The ML-307 RAWIN is made of balsa wood and gets destroyed when it comes back to the ground, so there was not a "return for reward" marking on it. This is the source of the hieroglyphics markings discovered at the Roswell UFO crash sight. The garment company that made the reflectors used a tape that they had on hand to reinforce the construction and it happened to have poorly printed flower designs. The is covered in a chapter of the book: UFO Crash at Roswell: The Genesis of a Modern Myth edited by
MIL-R-49315 Radiosonde ML-659(V), Family of
PRC68, Alphanumeric Index of Web pages, Contact, Products for Sale
Page Created 17 March 2017