Whole-disk observations of Jupiter, Saturn, and Mars in millimeter/submillimeter bands

New balloon-borne observations of whole-disk brightness ratios for Jupiter, Saturn, and Mars are reported in four millimeter/submillimeter bands of bandwidth Delta nu approximate to 1-2 cm(-1). Using the effective planetary radii of Hildebrand et al., we find that TMars/TJupiter = 1.158 +/- 0.015, 1.189 +/- 0.015, 1.470 +- 0.019, and 1.515 +/- 0.019 and T-Saturn/T-Jupiter = 0.833 +/- 0.012, 0.758 +/- 0.010, 0.818 +/- 0.012, and 0.840 +/- 0.012, at nu = 5.7, 9.5, 16.5, and 22.5 cm(-1), respectively. Using models for the brightness temperature of Mars, we also give the whole-disk brightness temperatures for Jupiter and Saturn for the four frequencies.