Digitally-modulated HF communications reliability: modifications to ITU-R Rec. P.533 propagation model and the associated computer program REC533

Barclay, Lisa K.; Behm, C.; Carroll, Steven

doi:10.1049/cp.2009.0037

Cited by 4 publications

(4 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The computer program makes use of the REC533 developed by the Institute of Telecommunications Science (ITS) that supports ITU-R P.533 [5][6]. The goal of frequency prediction is to obtain the frequency of optimum(FOT) under actual communication time.…”

Section: Model Verificationmentioning

confidence: 99%

Method for the prediction of the frequency of airborne high-frequency circuits at high-altitude and long-distance communication

Xia

2024

Third International Conference on Electronic Information Engineering, Big Data, and Computer Technology (EIBDCT 2024)

View full text Add to dashboard Cite

During the test flight of civil aircraft, the prediction method recommended by ITU-R P.533 was used to predict the frequency of the high frequency(HF) system at the situation of the high-altitude and long-distance communication. There were many cases which the communication effect was lower than the design expectations. Through comparative analysis of test flight scenarios and scenarios recommended by ITU-R P.533, it is found that the flight altitude of the aircraft is a key factor affecting the accuracy of frequency prediction, and the communication distance will also exacerbate the impact of flight altitude. This paper establishes the test flight model of the airborne high frequency system to obtain the correction amount of flight altitude and communication distance for the frequency prediction. It proves the correctness and effectiveness of the method discussed in this paper through multi-scenario test flights.

show abstract

Section: Model Verificationmentioning

confidence: 99%

Method for the prediction of the frequency of airborne high-frequency circuits at high-altitude and long-distance communication

Xia

2024

Third International Conference on Electronic Information Engineering, Big Data, and Computer Technology (EIBDCT 2024)

View full text Add to dashboard Cite

show abstract

“…However, these methods have some limitations, e.g., they only include the effect of specular reflections, only three hops from each ionospheric layer are calculated, and the underlying databases are monthly and hourly in nature, so predictions cannot be made for individual days. The ITU‐R have published a method of calculating the delay spread using such prediction techniques [see ITU‐R , 2007; Barclay et al , 2009] and this has been incorporated in the software package REC533 (now called ITUHFPROP), but not VOACAP, available from the Institute for Telecommunications Services (ITS) website (elbert.its.bldrdoc.gov). However, this implementation is based on using the median signal power or signal‐to‐noise ratio (SNR), which, as will be demonstrated in this paper, can often lead to incorrectly predicted values.…”

Section: Introductionmentioning

confidence: 99%

“…A recent paper [ Stocker and Warrington , 2011a, 2011b] presented a ‘brute force’ method of calculating ITU‐R multipath spread (IMPS) [ ITU‐R , 2007; Barclay et al , 2009] from VOACAP predictions that included the effect of the SNR probability density functions (pdf). The predictions of spread were compared with observations obtained over several sub‐auroral paths with generally good agreement at sunspot minimum, but poorer performance at sunspot maximum because the presence (or otherwise) of high order modes (e.g., 3F2) is not well predicted by VOACAP at that time for these paths.…”

Section: Introductionmentioning

confidence: 99%

Fast and accurate calculation of multipath spread from VOACAP predictions

Stocker

2012

Radio Science

View full text Add to dashboard Cite

[1] Improved predictions of multipath spread at HF have been obtained from VOACAP by including the effect of probability distribution functions of the signal power rather than just taking the median signal power. A Monte Carlo calculation method has been adopted that is superior in terms of accuracy and computation speed over the brute force method previously employed. The predictions of multipath spread are generally comparable with the values measured over an 1800 km sub-auroral path. The new method will be useful to those planning or operating digitally modulated radio systems in the HF band since these can be adversely affected by multipath spread.Citation: Stocker, A. J. (2012), Fast and accurate calculation of multipath spread from VOACAP predictions, Radio Sci., 47, RS4005,

show abstract

“…Measurements are first presented for a path from Uppsala‐Leicester during sunspot maximum, second for the same path, but at solar minimum, and lastly for a slightly longer path (Nurmijärvi‐Leicester) also at solar minimum. The predictions of delay spread are based on the definition recently introduced by the International Telecommunication Union Radiocommunication Sector (ITU‐R) [ ITU‐R , 2007; Barclay et al , 2009] although VOACAP [ Lane , 2001] is used rather than ITU‐R [2009]. The results given here form the first systematic comparison between predicted and experimental values of the new delay spread parameter.…”

Section: Introductionmentioning

confidence: 99%

The effect of solar activity on the Doppler and multipath spread of HF signals received over paths oriented along the midlatitude trough

Stocker

Warrington

2011

Radio Science

View full text Add to dashboard Cite

[1] Measurements of the Doppler and delay spread associated with HF signals propagating along an oblique (1440 km) path tangential to the midlatitude ionospheric trough are presented for sunspot maximum and minimum. During the day, Doppler spread is independent of solar activity, but for winter and equinoctial nights, it is very much higher at sunspot maximum. The delay spread is also generally higher at sunspot maximum for all seasons and times of day. For sunspot minimum, measurements from a second, longer path (1800 km) are also presented. The observed Doppler and delay spreads are similar for both paths. Finally, a novel method of more accurately deriving the delay spread defined by the International Telecommunication Union (i.e., the largest delay spread including all modes that have a peak power within a user-defined threshold of that of the strongest mode) from Voice of America coverage analysis program (VOACAP) predictions is presented. For the first time, the predicted values are compared with the measured delay spreads and, while there is generally good agreement at sunspot minimum, the agreement at sunspot maximum tends to be poor because the behavior of the high-order ionospheric modes (e.g., 3F2) is not well predicted by VOACAP.Citation: Stocker, A. J., and E. M. Warrington (2011), The effect of solar activity on the Doppler and multipath spread of HF signals received over paths oriented along the midlatitude trough, Radio Sci., 46, RS1014,

show abstract

Digitally-modulated HF communications reliability: modifications to ITU-R Rec. P.533 propagation model and the associated computer program REC533

Cited by 4 publications

References 0 publications

Method for the prediction of the frequency of airborne high-frequency circuits at high-altitude and long-distance communication

Method for the prediction of the frequency of airborne high-frequency circuits at high-altitude and long-distance communication

Fast and accurate calculation of multipath spread from VOACAP predictions

The effect of solar activity on the Doppler and multipath spread of HF signals received over paths oriented along the midlatitude trough

Contact Info

Product

Resources

About