AshimaCore flying on a few different frames. This is actually the same AshimaCore brain in all the movies – it only takes a couple of minutes to move it from frame-to-frame. We added some new levels to our Kickstarter project for people just wanting to get an “almost ready to fly” quad (the “almost” is because we can’t reasonably ship a 100% assembled quad in the mail).
We also have some stills of the various frames here.
We launched the AshimaCore Kickstarter project today! The project has a few different combinations of the main board, the programmer / power board, various XBee antennas, debugger, and extras available. The goal is to get a batch of the boards built using automated production and to establish a production line that we can setup for distribution via an electronics / hobby retailer.
A month or so ago we showed you the unpopulated versions of our flier boards. Since then, we populated the main processor board and its daughter programmer / power board and been doing some testing. The image below shows the prototype main and daughter boards, along with a penny and a micro-SD card for scale.
We’ve started calling the combined unit the AshimaCore. It packages together a few nice pieces of kit that we think are likely to be of use for other projects. Here’s what is in the AshimaCore:
- STM32F4: a 168 MHz, ARM Cortex M4 with FPU, 1 Mb Flash, 192K memory
- MPU 9150: a compact, collocated, co-aligned accelerometer, gyro, and mag
- The usual host of digital, analog, and bus I/O that you expect for microcontrollers
Some times while working on one project, it ends up being necessary to build a tool that doesn’t exist in the form you want. That recently happened while we were building our open-source STM32F libraries. The result of this, however, turned out to be kind of cool and we figured it might be useful for others. So we stuck it in a GitHub repo.
What the code does is help pdftotext to extract well delineated (black rectangular bounded) table cells, and outputs them in a number of different formats for use with down stream tools. In one format, the code can output the scanned table and colour code what it thinks are distinct cells, so you can check that it’s getting things right (see figure, below).
The first 90 Sols of REMS data were released on the Planetary Data System on March 20. To make the datasets a little easier to use, Chris Lee at Ashima Research has processed the files from the PDS into NetCDF format. The files can be found in both NetCDF versions 3 and 4 on Ashima’s Mars climate center website.
The latest flight boards are back from the manufacturer. On the right at top we have the “wing” electronic speed controller (ESC) for the “Pod” flier, and below it a more standard rectangular form-factor version of the ESC. On the left is the main processor and sensor board (top) and its associated daughter board. For reference, the short axis on the rectangular ESC is 2.8 cm, or just over 1 inch.
Over the last few months we’ve been working on the board designs for our main flight controller, the mini hexcopter esc’s (electronic speed controllers), the vehicle sensor board, and a commercial esc board that shares all of the non-hexcopter-specific functions of our internal esc board but in a more standard rectangular form factor. A lot of time is spent on things like playing around with layout. Here, for your viewing pleasure, is a video of the kind of stuff involved. We thought this was fun just seeing the board tweaked around. Admittedly, this might be a hard-core geek thing, but it made us smile…
Its is sometimes popularly assumed that “we know Mars had an ocean” or “we know Mars had running rivers.” While these ideas have certainly been speculated about, it is far from true that we “know” these things. Several major problems lead to the science community’s uncertainty on how warm and wet early Mars likely was – and hence the uncertainty over whether oceans and true rivers ever existed on Mars. From a climate dynamics perspective, the biggest problem is it is very hard to figure out how Mars could have been warm enough. This is an ongoing problem, but a paper written by our colleague Michael Mischna at JPL and coauthored by researchers at Ashima Research (and using the planetWRF model) looks at how the combination of changes in the planetary tilt, volcanic emission of gases including sulphur dioxide, and differences in surface reflectivity might possibly have allowed liquid water to exist stably on the surface. The uncorrected proof was just put online. We will update this post with a link to the fully-published paper when it becomes available.
Our new paper, out in Icarus, looks at whether numerical models – and specifically our Venus model that is based on the GFDL FMS general circulation model (GCM) – are capable of simulation Venus’ atmospheric circulation. Venus is the most tricky terrestrial atmosphere to properly simulate, and it has variously been suggested that numerical conservation in the models might limit their use. By numerical conservation, we mean the ability of the mathematical representations of the circulation to maintain conserved properties like energy, or in this case, angular momentum (AM). Our Icarus paper looks at the total AM evolution, and how it depends on physical torques (i.e. real stuff) and spurious torques from numerical problems in the dynamics. The attached plot shows the spin-up (from rest) of the Venus atmosphere in the model. The red line shows the total atmospheric value, while the blue line shows the contribution from physics. The “bouncing” of the lines after spinup (about 100 Venus years) represent natural oscillations of AM between the atmosphere and the solid planet and are less than about 5%. That the blue and red lines track so closely shows that the model is gaining almost all of its AM from physically-valid torques – model noise is not dominant or even significant. These kinds of tests are crucial for moving forward to more complete models of Venus’ atmosphere.
We just had a paper describing our “K Distribution Method” (KDM) radiative transfer / heating model for Mars come out it JGR-Planets. The code is a flexible tool that allows arbitrary mixtures of gases and aerosols in the atmosphere to influence the transfer of visible (solar) and planetary thermal photons, and consequently how much the atmosphere heats and cools by these interactions. In other words, how much greenhouse effect is generated and how much the surface is shaded. The KDM is used within our planetWRF Mars global climate and weather model. KDM methods have been used in Earth models for a couple of decades and are now used in a few other planetary models. It greatly increases the flexibility of the model for examining ancient and potentially very different climates on Mars, as well as allowing more accurate investigation of multiple aerosols and gases in the current atmosphere.