The Sun-spot Period

Digital Sun Sensor Multi-Spot Operation

The operation and test of a multi-spot digital sun sensor for precise sun-line determination is described. The image forming system consists of an opaque mask with multiple pinhole apertures producing multiple, simultaneous, spot-like images of the sun on the focal plane. The sun-line precision can be improved by averaging multiple simultaneous measures. Nevertheless, the sensor operation on a ...

Spot Sizes on Sun-like Stars

The total area coverage by starspots is of interest for a variety of reasons, but direct techniques only provide estimates of this important quantity. Sunspot areas exhibit a lognormal size distribution irrespective of the phase of the activity cycle, implying that most sunspots are small. Here we explore the consequences if starspot areas were similarly distributed. The solar data allow for an...

Inferno in Embedded Space: Porting to the Sun SPOT

We report, here, on a project to port the Inferno operating system to the Sun SPOT sensor platform. The port provides support for the temperature and light sensors, the threeaxis accelerameter, LEDs, momentary contact switches, and GPIO pins. Communication among sensors is provided by an IPv6 implementation running over the integrated 802.15.4 radios.

The Direction of Rotation of Sun-Spot Vortices.

anyMAC: adapting the Sun SPOT architecture for MAC development

The Sun SPOT platform allows sensor network nodes to be programmed in Java and is therefore well suited for prototyping new sensor network protocols. The design of the Sun SPOT network stack however, makes it hard to replace the default IEEE 802.15.4 based MAC implementation. We therefore introduce the ‘anyMAC project’: a number of alterations to the default Sun SPOT network stack. The resultin...