Using ionosounders to relay encrypted and sensitive information in politically sensitive regions
A modern approach to transmitting intelligence messages with ~99% uptime

Ionsounders and Ionosounder networks have long been used to observe the height-vs-frequency of the Ionsphere's 3 primary layers along a given path.

Ionosounders provide near real time information along a fixed ionospheric path like

To most ordinary people, and suspicious governments these scientific instruments are not at all interesting. Yet, Ionosondes provide a of near optimal way of transmitting up to {64 KB / day} of secure traffic for a single dedicated Point-to-Point Ionsounde link. Evidence suggests that a chain of 64 ionosoundes could send 1 KB of traffic each day. This strategic capability has historically never been significantly used, as few modern (5th and 6th generation) ionosoundes have the ability to send data.

The data transfer capability of Ionosounders is little known and little exploited, as only 2 or 3 modern (5th and 6th generation) Ionosuonders have ever offered the capability. This data transmitting capability (binary, not Morse Code) is becoming more popular as it allows each frequency to be checked for its error correction rates, not just is analog propagation characteristics.

History of the ionosounder

The basic ionosonde technology was invented in 1925 by G. Breit and M. A. Tuve. The technology was further developed in the late 1920s by a number of prominent physicists, including Edward Victor Appleton.

The term "ionosphere" and hence "ionosounde" were proposed by Robert Watson-Watt.

An ionosonde is used for finding the optimum operation frequencies for broadcasts or two-way communications in the high frequency range, but in doing so reveals the height of the various ionosphere layers (and their electron densities) in near real time. Ionosounders are classifiable as RADAR systems, as they have many operational similarities to Atmospheric Doppler Radar systems.

How could an ionosunder network be implemented

Well, lets assume a target region (Indonesia)

Academic cover and other issues

Data transfer mechanisms or "Minimizing intercept probability"

Essential principals

Messaging protocol (generalized)

When message is already compiled for transmission (encrypted, with some error correction) ...

Alert HQ in next available sweep at predetermined (frequencies, emission mode, message mode);
Wait for HQ to acknowledge it is in Sweep-mode-accept-message mode...
On predetermined sweep mode for data transfer

Run sweep until Contact-Point-Frequency[1 ... N] is reached
Send Chunk [1 of N]


Alert HQ message terminates;
Resume normal sweep mode;

This method could be implemented as a bit transfer protocol instead of a symbol transfer protocol, but the protocol mechanisms would be substantially different.

While Node-to-HQ-sweep (node is master, HQ is slave; done every other sweep for example)

Network issues and benefits
Such an ionosunde network must be syncronizable to UTC with a tolerance of 10ms to 50ms depending on sweep speed. This can be done within the network -- the HQ node can transmit time signals -- or outside : as in Europe and the Americas time signal stations are readily available.

In order for an ionosounder network to be able to provide data, it must be part of a network.
Networking function, and network relationship
Cost and design issues

Ideally all the nodes involved should be powered by PCs of a type similar to "One Laptop Per Child" or a computer not much more complex than that. The cost for such a unit is under (250 USD, 200 EUR, 300 AUD) in 2010.

The ionosounder would be assumed to have a good transmitter and receiver, but could be able to pass on digitized audio to the PC for further processing. The cost of the ionosounder would be assumed to be under (2000 USD, 1000 EUR, 3000 AUD), where the ionosounder would have no more than 200 w of output power.

Probably it is best to have 3 frequencies set aside for the individual ionsounder nodes to listen to, so that they can be updated with the most up to date network configuration (frequencies, operating modes, reporting schedules, node-priority-lists)
Ionsounding stations can be powered by solar power, and this should be considered as a viable solution in remote regions. The typical load that should be assumed is 2 kw for all equipment, so 5 kW in solar power would be required to run the systems and charge the batteries for night operation. One can assume an ionosounder power of 500 watts, but for single hop paths 150 watts will be more optimal.

Technical references

Cryptography & Intelligence Gathering Telecom

Annex (See [1 2 3] for table source calculations)

Burst Morse Code
          Table Section

Created by
Max Power
Power Broadcasting

Original idea
15 May 2009

10 March 2010

Last revised
05 April 2013
Burst Morse Table added + sources