Meteor scatter burst communication system

• US 4,277,845 A
• Filed: 07/29/1977
• Issued: 07/07/1981
• Est. Priority Date: 07/29/1977
• Status: Expired due to Term

• Current Assignee: Rockwell International Corporation
• Original Assignee: Rockwell International Corporation
• Inventors: Smith, Dale K., Donich, Thomas G., Dickerson, Bobby V., Leader, Raymond E.
• Primary Examiner(s): Murray, Richard
• Assistant Examiner(s): Chin, Tommy P.
• Application Number:
  US05/820,206
• Time in Patent Office: 1,439 Days
• Field of Search: 325/65, 325/42, 325/31, 325/122, 455/64, 455/67, 455/56, 455/57, 455/49, 455/53, 455/88, 455/52, 340/854, 340/855, 340/857, 340/861, 343/18 R, 343/18 D, 343/18 E
• US Class Current: 455/505
• CPC Class Codes: H04B 7/22 Scatter propagation systems , e.g. ionospheric, tropospheric or meteor scatter

Abstract

The specfication discloses a meteor burst communication system including at least two spaced apart master stations, in association with a plurality of groups of remote stations spaced at locations remote from the master stations, with each group being associated with one of the master stations. Each of the master stations includes a radio transmitter for transmitting probing digital radio signals having address portions which are directed from the master station for reflection from meteor trails to the remote stations associated with the master station. Circuitry is provided to vary the length of the address portions transmitted by the master station in dependence upon desired signal-to-noise and timing considerations. Each of the remote stations includes a radio receiver for receiving the reflected probing digital radio signals from the master stations. Each of the remote stations also includes at least one sensor of physical characteristics such as snow depth, rain fall or the like. The remote stations further include a predetermined unique digital address sequence stored therein and include circuitry to compare the received address portions from the master station with the stored digital address sequence. The remote stations each include a transmitter for transmitting digital data representative of the output of the associated sensor to the master station via reflection from a meteor vapor trail, if the received address portion compares with the stored digital address sequence in accordance with predetermined criteria.

Claims

1. A meteor burst communications system comprising:

at least one master station,

a plurality of remote stations spaced at locations remote from said master station,

said master station including a radio transmitter for transmitting probing digital radio signals having address portions of selectively variable length, said probing digital radio signals being directed from said master station for reflection from meteor vapor trails to said remote stations,

each of said remote stations including a radio receiver for receiving said reflected probing digital radio signals from said master station,

each of said remote stations including address recognition circuitry having a predetermined digital address sequence stored therein and further having means to compare the received address portions with said stored digital address sequence,

at least one sensor of physical characteristics connected with each said remote station, and

each remote station including a transmitter for transmitting digital data representative of the output of said sensor to said master station via reflection from a meteor vapor trail if said received address portion compares with said stored digital address sequence in accordance with predetermined criteria based upon the length of said received address portion.

2. The meteor burst communications system of claim 1 and further comprising means in said master station for transmitting an acknowledge signal to each remote station which answers said probing digital radio signals transmitted by said master station.

3. The meteor burst communications system of claim 2 and further comprising:

means in each of said remote stations for inhibiting further operation of said remote stations for a predetermined time interval after the reception of said acknowledge signal.

4. The meteor burst communications system of claim 3 and further comprising:

address means at said master station for transmitting an address to an inhibited remote station to override said means for inhibiting and allowing communication between said master station and said remote station.

5. The metero burst communications system of claim 1 wherein said address portion of said probing digital radio signals has a predetermined variable length up to n bits, the less the number of bits contained in said address portion the greater the number of remote stations which will respond to said probing digital radio signals.

6. The meteor burst communications system of claim 5 and further comprising:

storage means in said master station for maintaining a record of which remote stations have responded to a probing digital radio signal having an address portion encompassing a plurality of remote stations, and

means responsive to said storage means for increasing the number of bits in said address portion to exclude probing of remote stations which have already responded.

7. The metero burst communications system of claim 1 and further comprising:

at least two spaced apart master stations each transmitting a different probing digital radio signal,

means for setting said stored digital address sequence at a remote station such that said remote station responds to either of said master stations.

8. The metero burst communications system of claim 7 and further comprising:

a service center having means for communicating with and controlling operation of each of said master stations.

9. The meteor burst communications system of claim 7 and further comprising:

means for communicating between said master stations to apprise each master station of the probing progress of the other master station.

10. In a meteor burst communications system wherein a master station intermittently contacts a plurality of remote stations, the combination comprising:

means for transmitting a digital probing radio signal having an address field of n bit capacity,

means for computing a digital address having a number of bits up to n bits dependent upon a desired number of remote stations to be contacted, and

means for applying said digital address to said transmitting means for transmission in said address field.

11. The combination of claim 10 and further comprising:

means responsive to the reception of responses from the remote stations for varying the number of bits in said digital address.

12. A meteor burst communications system comprising:

at least one master station,

a plurality of remote stations spaced at locations remote from said master station,

said master station including a radio transmitter for transmitting probing digital radio signals, said digital radio signals being directed from said master station for reflection from meteor trails to said remote stations,

each of said remote stations including a radio receiver for receiving said reflected probing digital radio signals from said master station,

at least one sensor of physical characteristics connected with each said remote station,

each remote station including a transmitter for transmitting at a specified frequency digital data representative of the output of said sensor to said master station via reflection from a meteor trail,

said master station including a plurality of antennas connected to discrete radio receiving channels for simultaneously receiving digital data from a plurality of said remote stations,

means connected to said radio receiving channels for storing the received digital data for subsequent use, and

means for varying said probing digital radio signals in response to said received digital data.

13. The meteor burst communications system of claim 12 wherein said remote stations are spaced apart sufficiently that said digital data is transmitted from each remote station along a different reflection path to said master station.

14. A meteor burst communications system comprising:

at least two spaced apart master stations,

a plurality of groups of remote stations spaced at locations remote from said master stations and each group associated with one of said master stations,

each said master station including a radio transmitter for transmitting probing digital radio signals having address portions for being directed from said master station for reflection from meteor trails to said remote stations associated therewith,

each of said remote stations including a radio receiver for receiving said reflected probing digital radio signals from said master stations,

at least one sensor of physical characteristics connected with each said remote station,

each remote station including a transmitter for transmitting digital data representative of the output of said sensor to said master station via reflection from a meteor trail, and

means for detecting when one master station receives a response from a remote station associated with another master station and for notifying said another master station to eliminate the requirement of further probing for the received remote station.

15. The meteor burst communications system of claim 14 and further comprising:

a portable test unit for conducting diagnostic tests on said remote stations and including means storing an address which responds to address portions of probing digital radio signals generated by each of said master stations to enable communication between said portable test unit and any of said master stations.

16. A meteor burst communications system comprising:

at least one master station,

a plurality of remote stations spaced at locations remote from said master station,

said master station including a radio transmitter for transmitting probing digital radio signals having an address portion of selectively variable length in order to address any one or any group of said remote stations, said digital radio signals being directed from said master station for reflection from meteor trails to said remote stations,

each of said remote stations including a radio receiver for receiving said reflected probing digital radio signals from said master station,

each of said remote stations including address recognition circuitry having a predetermined digital address sequence stored therein and further having means to compare the received address portions with said stored digital address sequence,

at least one sensor of physical characteristics connected with each said remote station, and

each remote station including a transmitter for transmitting digital data representative of the output of said sensor to said master station via reflection from a meteor trail if said received address portion compares with the most significant bits of said stored digital address sequence.

17. The meteor burst communications system of claim 16 wherein said sensor connected to said remote station comprises means for sensing the amount of precipitation.

18. The meteor burst communications system of claim 16 wherein said sensor comprises means for sensing the amount of snow in the area of said remote location.

19. The meteor burst communications system of claim 16 wherein said sensor comprises means for sensing the temperature.

20. The meteor burst communications system of claim 16 wherein said sensor generates analog signals, an analog-to-digital converter provided for converting said analog signals to digital signals for transmission from said remote station.

21. The meteor burst communications system of claim 16 wherein said probing digital radio signals comprise a plurality of sequentially transmitted data fields.

22. The meteor burst communications system of claim 21 wherein one of said data fields comprises a plurality of digital bits to determine proper bit phase.

23. The meteor burst communications system of claim 21 wherein one of said data fields comprises a plurality of synchronization bits.

24. The meteor burst communications system of claim 21 wherein one of said data fields comprises said address portion which has a number of bits dependent upon the number of remote stations desired to be probed.

25. The meteor burst communications system of claim 24 wherein said address portion includes bits which indicate the number of bits in the address.

26. The meteor burst communications system of claim 16 and further comprising:

at least one portable test unit for being transported to each of said remote stations,

means in said test unit for performing diagnostic tests on said remote stations, and

means in said test unit for receiving and responding to predetermined address signals transmitted by said master station.

27. In a meteor burst communications system having a master station and a plurality of remote stations, a master station comprising:

a transceiver having a transmitter portion;

a digital computer for generating commands to control the transmitter and for providing a variable bit probe to be transmitted to selected remote stations; and

master station control logic for interfacing between said computer and said transceiver, said control logic comprising;

means for holding probe data bits from said computer and providing a serial bit stream to said transceiver; and

means for holding a count of the total number of data bits in the probe and providing an indication that the last data bit has been provided to said transmitter.

28. The master station of claim 27 wherein said control logic further comprises:

means for generating a transmit interrupt request to said computer to acquire a new probe.

29. The master station of claim 28 wherein said transmit interrupt means in said control logic comprises:

means for indicating that no probe is available to be entered in said probe data bit holding means; and

means for generating an interrupt code to identify the interrupt source to said computer.

30. The master station of claim 27 wherein said control logic further comprises:

means for keying on and off the transmitter portion of said transceiver.

31. The master station of claim 27 wherein said transceiver has a receiver portion comprising a number of separate receiving channels, and wherein said control logic further comprises:

means for each receiver channel for storing data bits received in a transmission from one of the remote stations;

means for indicating that received data is available for processing; and

means for generating an interrupt code identifying the receiver channel to said computer and providing an interrupt request to the computer.

32. In a meteor burst communications system having a master station for transmitting variable length probe signals to a plurality of remote stations, each remote station comprising:

a transceiver having a transmitter portion and a receiver portion;

said receiver portion having means for detecting the variable length probe signals,

data acquisition means for obtaining data for transmission to the master station over said transmitter portion; and

34. The remote station of claim 32 wherein said control logic comprising:

means for keying on and off the transmitter portion of said transceiver;

means for supplying data from said data acquisition means to the transmitter; and

means for generating a check character to be inserted into the transmitted data stream.

36. The method of claim 34 wherein the generation of a new polling sequence involves:

accumulating the identification of remote stations that have responded within a predetermined period of time;

reporting data received from the remote stations to be polled that have responded within the predetermined time period; and

generating a polling sequence to poll the remaining remotes in the group.

37. The method of claim 34 wherein the period of time that each probe in the polling sequence is transmitted is dependent upon the number of probes in the polling sequence.

38. The method of claim 34 wherein the probe code in the new polling sequence is reduced in the number of bits to increase the number of remote stations polled.

39. The method of claim 34 wherein the probe code in the new polling sequence is increased in the number of bits to reduce the number of remote stations polled.

33. remote station control logic for interfacing between said transceiver and said data acquisition means, said control logic comprising:

means for defining the current state of the remote station;

means for accepting probe data bits received and detected by said receiver portion;

means for providing a count of the number of bits in each field of a received probe, said means being reset at the start of a field and incrementing as each bit in the field is received;

means for sequentially comparing station address code bits with received probe address bits; and

means for outputting data to said data acquisition means.

35. A method of meteor burst communication, comprising the steps of:

generating a polling sequence comprising a series of probes, each probe being a specific binary code of a predetermined number of bits;

transmitting each probe in said polling sequence for a predetermined period of time;

receiving said transmitted probes at a plurality of remote stations, each station having an identifying address;

transmitting response signals from each of the remote stations polled by each probe code; and

generating a new polling sequence to poll a group of specific remotes in dependence upon the identification of the remote stations responding, the probes in the new polling sequence being varied in the number of bits in the probe code from the probes in the previous polling sequence.