Abstract: A shade analysis device includes an accelerometer providing samples that represent an elevation defined by a sighting reference, an electronic compass providing samples that represent an azimuth heading defined by the sighting reference, and a processor under the control of a program included in the shade analysis device, acquiring an array of the samples that represent an azimuth heading and an array of corresponding samples that represent the elevation, in response to tracing with the sighting reference, a skyline at an interface between an open sky and at least one solar obstruction over a range of azimuth headings.