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(TI-59) Winds Aloft
08-05-2020, 12:00 AM
Post: #1
(TI-59) Winds Aloft
An excerpt from Winds Aloft by Programmable Calculator, National Weather Digest, VoL 4, No.3, August 1979, pgs. 19-26

"                                       Abstract
Determination of upper level winds is important to many practicing meteorologists. The pilot balloon method of upper winds analysis is discussed. An algorithm is developed to calculate pibal upper winds with a programmable calculator. Program steps and sample results are presented for the Texas Instruments TI-59 calculator.

4. THE CALCULATOR ALGORITHM
The pibal algorithm (Figures 2 and 3) is designed for use with a programmable calculator of capacity similar to the Texas Instruments TI-59 calculator/PC-lOOA printer combination. As developed for the TI- 59, it requires 50 memory locations and 515 program steps. Table 2 lists the symbols used in the algorithm. For clarity, the program uses variable names, a function beyond the capability of the TI-59. In practice, the variable names represent calculator memory locations …
As described in the following sections, the algorithm is separated into four parts: balloon height determination, data input, balloon position and velocity calculation, and determination of standard level winds.

5. THE T1-59 PROGRAM
Figure 4 shows the program used in the TI-59 version of the pibal algorithm. It lists both the program steps and the pre-programmed memory contents needed to compute wnds aloft. The program is lengthy, but does not have to be reentered for each use. The TI-59 is equipped with magnetic recording cards which allow program storage much like a full sized computer. The entire pibal program can be recorded on two cards of two tracks each, and then read into the calculator whenever needed. " 

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SlideRule
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08-05-2020, 06:47 AM
Post: #2
RE: (TI-59) Winds Aloft
Very interesting, thank you.
I am curious as to whether the practise of tracking the balloon azimuth optically to determine position (and hence wind speed) is still commonly used. (As opposed to using GPS and a radio link).

Stephen Lewkowicz (G1CMZ)
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08-05-2020, 11:33 AM
Post: #3
RE: (TI-59) Winds Aloft
Hello!

(08-05-2020 06:47 AM)StephenG1CMZ Wrote:  I am curious as to whether the practise of tracking the balloon azimuth optically to determine position (and hence wind speed) is still commonly used. (As opposed to using GPS and a radio link).

As far as I know the optical tracking was mainly used for low level balloons to measure the cloud base. Once the balloon is inside or above clouds optical tracking is over anyway. Cloud bases are usually measured with ceilometers now, even smaller airfields have them.

By the way: Worldwide wind fields are sampled from "normal" commercial aircraft since many years. Because of the COVID outbreak, air traffic is redusced drastically and meteorologists are already complaining that because the lack of data their predictions have become less accurate.

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Max
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08-05-2020, 01:42 PM
Post: #4
RE: (TI-59) Winds Aloft
(08-05-2020 06:47 AM)StephenG1CMZ Wrote:  Very interesting, thank you.
I am curious as to whether the practise of tracking the balloon azimuth optically to determine position (and hence wind speed) is still commonly used. (As opposed to using GPS and a radio link).

On the Tonopah Test Range they use GPS and radio.
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08-06-2020, 08:54 AM (This post was last modified: 08-06-2020 10:42 AM by Nad.)
Post: #5
RE: (TI-59) Winds Aloft
Hello!

(08-05-2020 11:33 AM)Maximilian Hohmann Wrote:  Worldwide wind fields are sampled from "normal" commercial aircraft since many years. Because of the COVID outbreak, air traffic is redusced drastically and meteorologists are already complaining that because the lack of data their predictions have become less accurate

I read the U.S. has been hard hit due to a limited number of ground-based stations.

Will just have to get an Amish farmer to help with weather forecasts Smile

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