Mixing
What is a blind encoder?
up vote
7
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As I'm studying, I found that GPS has to have 5 satellites or 4 satellites with "blind encoders" to use RAIM.
What is a blind encoder and what is its purpose?
gps raim
edited 23 hours ago
Pondlife
49.7k8133272
asked yesterday
Mun Park
513
|
show 1 more comment
up vote
7
down vote
favorite
As I'm studying, I found that GPS has to have 5 satellites or 4 satellites with "blind encoders" to use RAIM.
What is a blind encoder and what is its purpose?
gps raim
edited 23 hours ago
Pondlife
49.7k8133272
asked yesterday
Mun Park
513
Can you reference the source you are learning from or provide the relevant quotes from it? Because as far as I can tell, RAIM needs 5 satellites for error detection and 6 for correction and there is no way around it. Also, I am not sure what “blind-encorder” is it talking about, but there does not seem to be anything called blind encoder around GPS.
– Jan Hudec
23 hours ago
An altitude encoder used with transponder? (no cockpit display): How does radar receive Mode C information?
– mins
23 hours ago
As I know, GPS knows our altitude (via blind encoder which is another point of reference for position information. Therefore we need only 4 satellite to trilaterate our position.
– Mun Park
23 hours ago
Closely related. I think you may be mixing some different things here: a blind encoder is usually part of an aircraft's altimeter, which has nothing to do with RAIM.
– Pondlife
23 hours ago
1
@MunPark GPS doesn't know your altitude. It knows the altitude of its satellites, but it has no idea what your altitude (or your position in any dimension) is. Your flight computers may know because of data from your altimeter(s), but the Global Positioning System doesn't know, as it's a transmit-only system that doesn't even know who is receiving its signals, let alone their altitudes.
– reirab
7 hours ago
|
show 1 more comment
up vote
7
down vote
favorite
up vote
7
down vote
favorite
As I'm studying, I found that GPS has to have 5 satellites or 4 satellites with "blind encoders" to use RAIM.
What is a blind encoder and what is its purpose?
gps raim
edited 23 hours ago
Pondlife
49.7k8133272
asked yesterday
Mun Park
513
As I'm studying, I found that GPS has to have 5 satellites or 4 satellites with "blind encoders" to use RAIM.
What is a blind encoder and what is its purpose?
gps raim
gps raim
edited 23 hours ago
Pondlife
49.7k8133272
asked yesterday
Mun Park
513
edited 23 hours ago
Pondlife
49.7k8133272
asked yesterday
Mun Park
513
edited 23 hours ago
Pondlife
49.7k8133272
edited 23 hours ago
Pondlife
49.7k8133272
edited 23 hours ago
Pondlife
49.7k8133272
49.7k8133272
asked yesterday
Mun Park
513
asked yesterday
Mun Park
513
asked yesterday
Mun Park
513
513
Can you reference the source you are learning from or provide the relevant quotes from it? Because as far as I can tell, RAIM needs 5 satellites for error detection and 6 for correction and there is no way around it. Also, I am not sure what “blind-encorder” is it talking about, but there does not seem to be anything called blind encoder around GPS.
– Jan Hudec
23 hours ago
An altitude encoder used with transponder? (no cockpit display): How does radar receive Mode C information?
– mins
23 hours ago
As I know, GPS knows our altitude (via blind encoder which is another point of reference for position information. Therefore we need only 4 satellite to trilaterate our position.
– Mun Park
23 hours ago
Closely related. I think you may be mixing some different things here: a blind encoder is usually part of an aircraft's altimeter, which has nothing to do with RAIM.
– Pondlife
23 hours ago
1
@MunPark GPS doesn't know your altitude. It knows the altitude of its satellites, but it has no idea what your altitude (or your position in any dimension) is. Your flight computers may know because of data from your altimeter(s), but the Global Positioning System doesn't know, as it's a transmit-only system that doesn't even know who is receiving its signals, let alone their altitudes.
– reirab
7 hours ago
|
show 1 more comment
Can you reference the source you are learning from or provide the relevant quotes from it? Because as far as I can tell, RAIM needs 5 satellites for error detection and 6 for correction and there is no way around it. Also, I am not sure what “blind-encorder” is it talking about, but there does not seem to be anything called blind encoder around GPS.
– Jan Hudec
23 hours ago
An altitude encoder used with transponder? (no cockpit display): How does radar receive Mode C information?
– mins
23 hours ago
As I know, GPS knows our altitude (via blind encoder which is another point of reference for position information. Therefore we need only 4 satellite to trilaterate our position.
– Mun Park
23 hours ago
Closely related. I think you may be mixing some different things here: a blind encoder is usually part of an aircraft's altimeter, which has nothing to do with RAIM.
– Pondlife
23 hours ago
1
@MunPark GPS doesn't know your altitude. It knows the altitude of its satellites, but it has no idea what your altitude (or your position in any dimension) is. Your flight computers may know because of data from your altimeter(s), but the Global Positioning System doesn't know, as it's a transmit-only system that doesn't even know who is receiving its signals, let alone their altitudes.
– reirab
7 hours ago
Can you reference the source you are learning from or provide the relevant quotes from it? Because as far as I can tell, RAIM needs 5 satellites for error detection and 6 for correction and there is no way around it. Also, I am not sure what “blind-encorder” is it talking about, but there does not seem to be anything called blind encoder around GPS.
– Jan Hudec
23 hours ago
Can you reference the source you are learning from or provide the relevant quotes from it? Because as far as I can tell, RAIM needs 5 satellites for error detection and 6 for correction and there is no way around it. Also, I am not sure what “blind-encorder” is it talking about, but there does not seem to be anything called blind encoder around GPS.
– Jan Hudec
23 hours ago
An altitude encoder used with transponder? (no cockpit display): How does radar receive Mode C information?
– mins
23 hours ago
An altitude encoder used with transponder? (no cockpit display): How does radar receive Mode C information?
– mins
23 hours ago
As I know, GPS knows our altitude (via blind encoder which is another point of reference for position information. Therefore we need only 4 satellite to trilaterate our position.
– Mun Park
23 hours ago
As I know, GPS knows our altitude (via blind encoder which is another point of reference for position information. Therefore we need only 4 satellite to trilaterate our position.
– Mun Park
23 hours ago
Closely related. I think you may be mixing some different things here: a blind encoder is usually part of an aircraft's altimeter, which has nothing to do with RAIM.
– Pondlife
23 hours ago
Closely related. I think you may be mixing some different things here: a blind encoder is usually part of an aircraft's altimeter, which has nothing to do with RAIM.
– Pondlife
23 hours ago
1
1
@MunPark GPS doesn't know your altitude. It knows the altitude of its satellites, but it has no idea what your altitude (or your position in any dimension) is. Your flight computers may know because of data from your altimeter(s), but the Global Positioning System doesn't know, as it's a transmit-only system that doesn't even know who is receiving its signals, let alone their altitudes.
– reirab
7 hours ago
@MunPark GPS doesn't know your altitude. It knows the altitude of its satellites, but it has no idea what your altitude (or your position in any dimension) is. Your flight computers may know because of data from your altimeter(s), but the Global Positioning System doesn't know, as it's a transmit-only system that doesn't even know who is receiving its signals, let alone their altitudes.
– reirab
7 hours ago
|
show 1 more comment
2 Answers
2
active
oldest
votes
up vote
17
down vote
A blind encoder is an altimeter that encodes pressure altitude and outputs it on a databus. They are "blind" in that they do not display data to the pilot. Most general aviation units use a parallel bus with Gillham encoding. More expensive units and air data computers use serial bus output, commonly ARINC 429.
Historically, the blind encoder existed to provide pressure altitude data to the transponder to enable Mode C reporting.
When it was proposed to use GPS as a primary means of navigation in the early 1990's, the FAA deemed that a means of ensuring the integrity of the signal was essential. The longer term solution was to establish WAAS which provided both augmentation and an integrity channel. The short term solution was to have the receivers include an internal monitor, which took on the name RAIM for Receiver Autonomous Integrity Monitor.
RAIM algorithms have evolved several times over the years. Since early GPS receivers were often single or 3 channel receivers, the use of altitude as a substitute for an additional satellite was common. (Altitude is just another range in the rho-rho computation.)
Later GPS receivers moved to 6 and 12 channel receivers, thus enabling RAIM algorithms that don't need altitude data except in extreme cases.
So yes, the number of satellites needed for a RAIM calculation can be reduced by one when pressure altitude is available from a blind encoder.
answered 21 hours ago
Gerry
10k12949
+1, I had no idea that there's a link between altitude encoding and RAIM. I'm not doubting your answer, but do you have any sources on the algorithms you mentioned?
– Pondlife
20 hours ago
3
The information is in the GPS MOPS, RTCA DO-229. The basics are covered in Appendix G—REQUIREMENTS FOR BAROMETRIC ALTIMETER AIDING in DO-229C. I'm not sure if the reference is still valid in the current version DO-229E. I do know that the newer version does require the use of FDE RAIM as the algorithms have evolved.
– Gerry
18 hours ago
thanks for that!
– Pondlife
18 hours ago
add a comment |
up vote
0
down vote
Receiver autonomous integrity monitoring
Receiver autonomous integrity monitoring (RAIM) is a technology developed to assess the integrity of global positioning system (GPS) signals in a GPS receiver system. It is of special importance in safety-critical GPS applications, such as in aviation or marine navigation
Check out the GPS article in this FAA newsletter to start with:
http://www.faa.gov/news/safety_briefing/2010/media/JanFeb2010.pdf
RAIM prediction is what is of primary concern for Non-WAAS equipped GPSs.
If you are WAAS equipped then you are good to go without doing prediction.
answered 11 hours ago
KARTIK GURNANI
1
New contributor
KARTIK GURNANI is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
add a comment |
2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
17
down vote
A blind encoder is an altimeter that encodes pressure altitude and outputs it on a databus. They are "blind" in that they do not display data to the pilot. Most general aviation units use a parallel bus with Gillham encoding. More expensive units and air data computers use serial bus output, commonly ARINC 429.
Historically, the blind encoder existed to provide pressure altitude data to the transponder to enable Mode C reporting.
When it was proposed to use GPS as a primary means of navigation in the early 1990's, the FAA deemed that a means of ensuring the integrity of the signal was essential. The longer term solution was to establish WAAS which provided both augmentation and an integrity channel. The short term solution was to have the receivers include an internal monitor, which took on the name RAIM for Receiver Autonomous Integrity Monitor.
RAIM algorithms have evolved several times over the years. Since early GPS receivers were often single or 3 channel receivers, the use of altitude as a substitute for an additional satellite was common. (Altitude is just another range in the rho-rho computation.)
Later GPS receivers moved to 6 and 12 channel receivers, thus enabling RAIM algorithms that don't need altitude data except in extreme cases.
So yes, the number of satellites needed for a RAIM calculation can be reduced by one when pressure altitude is available from a blind encoder.
answered 21 hours ago
Gerry
10k12949
+1, I had no idea that there's a link between altitude encoding and RAIM. I'm not doubting your answer, but do you have any sources on the algorithms you mentioned?
– Pondlife
20 hours ago
3
The information is in the GPS MOPS, RTCA DO-229. The basics are covered in Appendix G—REQUIREMENTS FOR BAROMETRIC ALTIMETER AIDING in DO-229C. I'm not sure if the reference is still valid in the current version DO-229E. I do know that the newer version does require the use of FDE RAIM as the algorithms have evolved.
– Gerry
18 hours ago
thanks for that!
– Pondlife
18 hours ago
add a comment |
up vote
17
down vote
A blind encoder is an altimeter that encodes pressure altitude and outputs it on a databus. They are "blind" in that they do not display data to the pilot. Most general aviation units use a parallel bus with Gillham encoding. More expensive units and air data computers use serial bus output, commonly ARINC 429.
Historically, the blind encoder existed to provide pressure altitude data to the transponder to enable Mode C reporting.
When it was proposed to use GPS as a primary means of navigation in the early 1990's, the FAA deemed that a means of ensuring the integrity of the signal was essential. The longer term solution was to establish WAAS which provided both augmentation and an integrity channel. The short term solution was to have the receivers include an internal monitor, which took on the name RAIM for Receiver Autonomous Integrity Monitor.
RAIM algorithms have evolved several times over the years. Since early GPS receivers were often single or 3 channel receivers, the use of altitude as a substitute for an additional satellite was common. (Altitude is just another range in the rho-rho computation.)
Later GPS receivers moved to 6 and 12 channel receivers, thus enabling RAIM algorithms that don't need altitude data except in extreme cases.
So yes, the number of satellites needed for a RAIM calculation can be reduced by one when pressure altitude is available from a blind encoder.
answered 21 hours ago
Gerry
10k12949
+1, I had no idea that there's a link between altitude encoding and RAIM. I'm not doubting your answer, but do you have any sources on the algorithms you mentioned?
– Pondlife
20 hours ago
3
The information is in the GPS MOPS, RTCA DO-229. The basics are covered in Appendix G—REQUIREMENTS FOR BAROMETRIC ALTIMETER AIDING in DO-229C. I'm not sure if the reference is still valid in the current version DO-229E. I do know that the newer version does require the use of FDE RAIM as the algorithms have evolved.
– Gerry
18 hours ago
thanks for that!
– Pondlife
18 hours ago
add a comment |
up vote
17
down vote
up vote
17
down vote
A blind encoder is an altimeter that encodes pressure altitude and outputs it on a databus. They are "blind" in that they do not display data to the pilot. Most general aviation units use a parallel bus with Gillham encoding. More expensive units and air data computers use serial bus output, commonly ARINC 429.
Historically, the blind encoder existed to provide pressure altitude data to the transponder to enable Mode C reporting.
When it was proposed to use GPS as a primary means of navigation in the early 1990's, the FAA deemed that a means of ensuring the integrity of the signal was essential. The longer term solution was to establish WAAS which provided both augmentation and an integrity channel. The short term solution was to have the receivers include an internal monitor, which took on the name RAIM for Receiver Autonomous Integrity Monitor.
RAIM algorithms have evolved several times over the years. Since early GPS receivers were often single or 3 channel receivers, the use of altitude as a substitute for an additional satellite was common. (Altitude is just another range in the rho-rho computation.)
Later GPS receivers moved to 6 and 12 channel receivers, thus enabling RAIM algorithms that don't need altitude data except in extreme cases.
So yes, the number of satellites needed for a RAIM calculation can be reduced by one when pressure altitude is available from a blind encoder.
answered 21 hours ago
Gerry
10k12949
A blind encoder is an altimeter that encodes pressure altitude and outputs it on a databus. They are "blind" in that they do not display data to the pilot. Most general aviation units use a parallel bus with Gillham encoding. More expensive units and air data computers use serial bus output, commonly ARINC 429.
Historically, the blind encoder existed to provide pressure altitude data to the transponder to enable Mode C reporting.
When it was proposed to use GPS as a primary means of navigation in the early 1990's, the FAA deemed that a means of ensuring the integrity of the signal was essential. The longer term solution was to establish WAAS which provided both augmentation and an integrity channel. The short term solution was to have the receivers include an internal monitor, which took on the name RAIM for Receiver Autonomous Integrity Monitor.
RAIM algorithms have evolved several times over the years. Since early GPS receivers were often single or 3 channel receivers, the use of altitude as a substitute for an additional satellite was common. (Altitude is just another range in the rho-rho computation.)
Later GPS receivers moved to 6 and 12 channel receivers, thus enabling RAIM algorithms that don't need altitude data except in extreme cases.
So yes, the number of satellites needed for a RAIM calculation can be reduced by one when pressure altitude is available from a blind encoder.
answered 21 hours ago
Gerry
10k12949
answered 21 hours ago
Gerry
10k12949
answered 21 hours ago
Gerry
10k12949
answered 21 hours ago
Gerry
10k12949
10k12949
+1, I had no idea that there's a link between altitude encoding and RAIM. I'm not doubting your answer, but do you have any sources on the algorithms you mentioned?
– Pondlife
20 hours ago
3
The information is in the GPS MOPS, RTCA DO-229. The basics are covered in Appendix G—REQUIREMENTS FOR BAROMETRIC ALTIMETER AIDING in DO-229C. I'm not sure if the reference is still valid in the current version DO-229E. I do know that the newer version does require the use of FDE RAIM as the algorithms have evolved.
– Gerry
18 hours ago
thanks for that!
– Pondlife
18 hours ago
add a comment |
+1, I had no idea that there's a link between altitude encoding and RAIM. I'm not doubting your answer, but do you have any sources on the algorithms you mentioned?
– Pondlife
20 hours ago
3
The information is in the GPS MOPS, RTCA DO-229. The basics are covered in Appendix G—REQUIREMENTS FOR BAROMETRIC ALTIMETER AIDING in DO-229C. I'm not sure if the reference is still valid in the current version DO-229E. I do know that the newer version does require the use of FDE RAIM as the algorithms have evolved.
– Gerry
18 hours ago
thanks for that!
– Pondlife
18 hours ago
+1, I had no idea that there's a link between altitude encoding and RAIM. I'm not doubting your answer, but do you have any sources on the algorithms you mentioned?
– Pondlife
20 hours ago
+1, I had no idea that there's a link between altitude encoding and RAIM. I'm not doubting your answer, but do you have any sources on the algorithms you mentioned?
– Pondlife
20 hours ago
3
3
The information is in the GPS MOPS, RTCA DO-229. The basics are covered in Appendix G—REQUIREMENTS FOR BAROMETRIC ALTIMETER AIDING in DO-229C. I'm not sure if the reference is still valid in the current version DO-229E. I do know that the newer version does require the use of FDE RAIM as the algorithms have evolved.
– Gerry
18 hours ago
The information is in the GPS MOPS, RTCA DO-229. The basics are covered in Appendix G—REQUIREMENTS FOR BAROMETRIC ALTIMETER AIDING in DO-229C. I'm not sure if the reference is still valid in the current version DO-229E. I do know that the newer version does require the use of FDE RAIM as the algorithms have evolved.
– Gerry
18 hours ago
thanks for that!
– Pondlife
18 hours ago
thanks for that!
– Pondlife
18 hours ago
add a comment |
up vote
0
down vote
Receiver autonomous integrity monitoring
Receiver autonomous integrity monitoring (RAIM) is a technology developed to assess the integrity of global positioning system (GPS) signals in a GPS receiver system. It is of special importance in safety-critical GPS applications, such as in aviation or marine navigation
Check out the GPS article in this FAA newsletter to start with:
http://www.faa.gov/news/safety_briefing/2010/media/JanFeb2010.pdf
RAIM prediction is what is of primary concern for Non-WAAS equipped GPSs.
If you are WAAS equipped then you are good to go without doing prediction.
answered 11 hours ago
KARTIK GURNANI
1
New contributor
KARTIK GURNANI is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
add a comment |
up vote
0
down vote
Receiver autonomous integrity monitoring
Receiver autonomous integrity monitoring (RAIM) is a technology developed to assess the integrity of global positioning system (GPS) signals in a GPS receiver system. It is of special importance in safety-critical GPS applications, such as in aviation or marine navigation
Check out the GPS article in this FAA newsletter to start with:
http://www.faa.gov/news/safety_briefing/2010/media/JanFeb2010.pdf
RAIM prediction is what is of primary concern for Non-WAAS equipped GPSs.
If you are WAAS equipped then you are good to go without doing prediction.
answered 11 hours ago
KARTIK GURNANI
1
New contributor
KARTIK GURNANI is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
add a comment |
up vote
0
down vote
up vote
0
down vote
Receiver autonomous integrity monitoring
Receiver autonomous integrity monitoring (RAIM) is a technology developed to assess the integrity of global positioning system (GPS) signals in a GPS receiver system. It is of special importance in safety-critical GPS applications, such as in aviation or marine navigation
Check out the GPS article in this FAA newsletter to start with:
http://www.faa.gov/news/safety_briefing/2010/media/JanFeb2010.pdf
RAIM prediction is what is of primary concern for Non-WAAS equipped GPSs.
If you are WAAS equipped then you are good to go without doing prediction.
answered 11 hours ago
KARTIK GURNANI
1
New contributor
KARTIK GURNANI is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
Receiver autonomous integrity monitoring
Receiver autonomous integrity monitoring (RAIM) is a technology developed to assess the integrity of global positioning system (GPS) signals in a GPS receiver system. It is of special importance in safety-critical GPS applications, such as in aviation or marine navigation
Check out the GPS article in this FAA newsletter to start with:
http://www.faa.gov/news/safety_briefing/2010/media/JanFeb2010.pdf
RAIM prediction is what is of primary concern for Non-WAAS equipped GPSs.
If you are WAAS equipped then you are good to go without doing prediction.
answered 11 hours ago
KARTIK GURNANI
1
New contributor
KARTIK GURNANI is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
answered 11 hours ago
KARTIK GURNANI
1
New contributor
KARTIK GURNANI is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
answered 11 hours ago
KARTIK GURNANI
1
answered 11 hours ago
KARTIK GURNANI
1
1
New contributor
KARTIK GURNANI is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
New contributor
KARTIK GURNANI is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
KARTIK GURNANI is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
add a comment |
add a comment |
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Can you reference the source you are learning from or provide the relevant quotes from it? Because as far as I can tell, RAIM needs 5 satellites for error detection and 6 for correction and there is no way around it. Also, I am not sure what “blind-encorder” is it talking about, but there does not seem to be anything called blind encoder around GPS.
– Jan Hudec
23 hours ago
An altitude encoder used with transponder? (no cockpit display): How does radar receive Mode C information?
– mins
23 hours ago
As I know, GPS knows our altitude (via blind encoder which is another point of reference for position information. Therefore we need only 4 satellite to trilaterate our position.
– Mun Park
23 hours ago
Closely related. I think you may be mixing some different things here: a blind encoder is usually part of an aircraft's altimeter, which has nothing to do with RAIM.
– Pondlife
23 hours ago
1
@MunPark GPS doesn't know your altitude. It knows the altitude of its satellites, but it has no idea what your altitude (or your position in any dimension) is. Your flight computers may know because of data from your altimeter(s), but the Global Positioning System doesn't know, as it's a transmit-only system that doesn't even know who is receiving its signals, let alone their altitudes.
– reirab
7 hours ago