A brief review of the simultaneous observations of solar total irradiance performed by the UARS ACRIM II (upper atmosphere research satellite active cavity radiometer irradiance monitor), EURECA SOVA 1 and SOVA 2 (European retrievable carrier platform solar variability experiments), ERBS ERBE (Earth Radiation Budget Satellite Earth Radiation Budget Experiment), Nimbus 7 ERB, and Atlas 1 and 2 in 1992--1993 (a period characterized as the declining phase of solar cycle 22), is presented in this paper. Statistical comparison of the irradiance values and the linear relationships among the time series are examined for the overlap period August 1992 to May 1993. The mean irradiance at 1 astronomical unit (AU) observed by the UARS ACRIM II, EURECA SOVA 1, EURECA SOVA 2, and ERBS ERBE is within the range of 1365.5--1366.9 W m-2, and high correlation (r2=0.94) exists among the time series. Linear regression models based on the measurements are used in estimating the observed irradiance and predicting the missing values. The challenge in establishing a homogeneous long-term database from the independent observations of shorter duration requires a clear understanding of the compatibility of the data sets and any instrument-related drift or degradation. ¿ American Geophysical Union 1996