VHF ApolLO Available

The VHF ApolLO board is in production now and will be available on March 1st for shipping.  We are taking online preorders for the board here and our distributor, Downeast Microwave, is taking phone orders.  The VHF ApolLO is the same design as the ApolLO-32 strap-programmable microwave oscillator, but it operates in the VHF region, 70-450MHz (some frequencies may require an inductor change).  More details and documentation will be posted in the next few weeks, but the oscillator has mounting holes for popular transverters and locks to 10MHz just as the ApolLO-32.

VHF ApolLO PCB

VHF ApolLO PCB currently in production

Tree Avoidance Map for US Rovers

If you’ve ever been roving with a big dish or microwave antennas that are not on a mast, you know that locating an area without trees can be very important.  A hilltop that looks good on an elevation map is not worth nearly as much if is is covered in trees.  Most rovers survey locations in advance of operating to find out which locations are actually as good as they might appear to be on a topo map.

Scientists at the Woods Hole Research Center (WHRC) have now produced a “biomass map” (read trees) from a number of sources including the Shuttle Radar Topography Mission (SRTM) data and other data from the USGS and the USFS.  The map has 30m resolution and so presumably could help a rover determine which areas are “tree infested” and which are not (I love trees, just not when roving).  I’ve not yet had a chance to look at the real usefulness of this data down to that resolution, but just glancing at the map gives you a very good idea where densities are best and worst.

Locating trees around the US using data from SRTM, USGS and USFS

United States Biomass Map © 2011 WHRC

Clicking on the map above to enlarge it and the map on the WHRC website can be zoomed and panned for even greater resolution.