pvl_relativeairmass

Gives the relative (not pressure-corrected) airmass.

Contents

Syntax

AM = pvl_relativeairmass(z)

AM = pvl_relativeairmass(z, model)

Description

Gives the airmass at sea-level when given a sun zenith angle z (in degrees) using a user-specified model.

Inputs

Available Air Mass Models

Outputs

Example 1

Use default model near AM 1.5

AM = pvl_relativeairmass(45)
AM =

    1.4126

Example 2

Compare models at low sun angles

AM = zeros(100,7);
z = zeros(100,1);
z = z+ (80:0.1:89.9)';
models = {'simple' 'kasten1966' 'youngirvine1967' 'kastenyoung1989' 'gueymard1993' ...
    'young1994' 'pickering2002'};
for i=1:7
    AM(:,i) = pvl_relativeairmass(z,models{i});
end
figure
plot(z,AM(:,1))
hold all
for i=2:7
    plot(z,AM(:,i))
end
ylim([0 40])
legend(models,'Location','NW')
xlabel('Solar Zenith Angle (deg)')
ylabel('Relative Air Mass')
title('Relative Air Mass Model Comparisons','FontSize',14)

References

[1] Kasten, F., 1965. A New Table and Approximation Formula for the Relative Optical Air Mass, Theo. and Appl. Climatology vol. 14(2), pp. 206-223.

[2] A. T. Young and W. M. Irvine, 1967. Multicolor Photoelectric Photometry of the Brighter Planets, The Astronomical Journal, vol. 72, pp. 945-950.

[3] Kasten, F., Young, A., 1989. Revised optical air mass tables and approximation formula, Applied Optics vol. 28(22), pp. 4735–4738.

[4] Gueymard, C., 1993. Critical analysis and performance assessment of clear sky solar irradiance models using theoretical and measured data, Solar Energy, vol. 51, pp. 121-138.

[5] Young, A. T., 1994. AIR-MASS AND REFRACTION, Applied Optics, vol. 33, pp. 1108-1110.

[6] Pickering, K. A., 2002. The Ancient Star Catalog. DIO, vol. 12.

See Also

pvl_absoluteairmass, pvl_ephemeris

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