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Back Soon

Been a long field season this year, which has kept me away from this site. Not over yet – still have one more session left, running through the end of next week. Then I’ll be back home, and hope to get this site cranking again soon.




Maps Of The Moon And Mars For Android

Application Name: Moon Maps

Description: Photo maps of the moon from Lunar Orbiter and Clementine.

Publisher’s website: Moon Map

Cost: Free (ad-supported)

Version/date reviewed: v.1.1.1  /  8-14-11

Phone/OS: Droid X / Android 2.3

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Android Market (mobile app only)
Android Market (browser)


Application Name: Mars Map

Description: Mars map from the Mars Global Digital Image Mosaic.

Publisher’s website: Atlogis Map Shop

Cost: Free (ad-supported)

Version/date reviewed: v.1.0.7  /  8-14-11

Phone/OS: Droid X / Android 2.3

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Android Market (mobile app only)
Android Market (browser)


Something a bit different – geography but not of the Earth, celestial geography of the Moon and Mars. Both apps are similar in appearance and function, not surprising since they’re both from the same company.

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Moon Maps starts off with a whole-moon display; locations of major features and Apollo landing sites are plotted in colored text. As you zoom in, more features are labeled …

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Until you get the highest possible zoom level …

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The horizontal “stripes” are an artifact of the imaging process. These are images from the Lunar Orbiter probes, shot in the 60s on roll film (pre-solid-state imaging), which was processed on the satellite in lunar orbit, scanned in strips, transmitted to Earth, then pieced together to form a continuous image.

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Moon Maps offers an alternative image source from the more-recent Clementine probe, but while the “stripes” are gone, the imagery tends to be darker and of poorer resolution than that from the Lunar Orbiter.

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The app comes with a searchable database of lunar features and Apollo landing sites; select a feature, and it will zoom to the correct location.

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The Mars Map app operates in a similar fashion, though it uses only one image set, the Mars Global Digital Image Mosaic, generated from Viking Orbiter imagery from the 1970s, carefully selected and heavily processed to make it as uniform in lighting as possible across the surface.

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Viking imagery isn’t quite as high in resolution as that from more recent Mars probes, but there’s still lots of interesting features visible …

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… like this great shot of the crater at the top of Olympus Mons (aka Olympus Rupes), one of the largest volcanoes in the solar system, shown here at highest map resolution. As with Moon Maps, there’s also a searchable database to help you locate specific objects, and the locations of probes that landed successfully on Mars (e.g. Viking, Pathfinder, Mars, Spirit and Opportunity).

Other thoughts: Can’t complain too much, since the apps are free, but the ads do take up a fair amount of screen space.

Final thoughts: Great apps for astronomy fans and map nerds alike. I hope the imagery gets updated in the near future with higher-resolution data.




Map Lightning Strikes With ThunderHunter

Application Name: ThunderHunter

Description: Uses the lightning flash and succeeding thunderclap to map the location of lightning strikes in real time

Publisher’s website: ThunderHunter

Cost: Free

Version/date reviewed: v.1.2  /  8-10-11

Phone/OS: Droid X / Android 2.3

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Android Market (mobile app only)
Android Market (browser)


It’s “monsoon” season here in Arizona, which means that more days than not, there’s a good chance of thunderstorms. ThunderHunter uses the delay in seeing the lightning flash and hearing the thunder to calculate approximately how far away a lightning strike is. If  you point the phone in the direction of the lightning strike, it uses the phone’s built-in compass and GPS to plot the approximate position of the strike.

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Starting up the app gives you the screen above; the compass in the upper right is live, and shows you the approximate compass direction your phone is pointed. When you see a lightning flash, quickly swivel the phone to point in  the direction you saw the lightning hit, and tap the button with the “eye/lightning” icon …

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Now wait for the thunderclap; when you hear it, tap the button with the “ear/lightning” icon …

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Since light travels almost instantaneously, but sound travels much slower (about 300 meters / second), ThunderHunter uses the difference in time between the flash and the thunder to calculate the distance. The arrow icon at lower left returns you back to the first screen, to wait for another lightning flash. The button at lower right takes you to a Google Maps view …

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… where it uses the calculated distance and the orientation of the phone to plot the location of the lightning strike (cloud/lightning icon);  your current position is plotted as the “green man” icon. The GPS will fire up to get your current position,  then turn off to minimize power use. Use the “arrow” button to go back to the previous screen.

Other issues: Don’t worry about not having the phone pointed in the right direction when the lightning hits. ThunderHunter uses the direction you’re facing when you tap the “ear” icon after hearing the thunder, so as long as you point the phone in the direction you saw the lightning before you hear the thunder, the direction and position will be plotted correctly.

Final thoughts: Clean, simple, fun, does what it’s supposed to. Most comparable apps only calculate distance, ThunderHunter goes the extra step and plots the position. Recommended. I will say that if you can see lightning and hear thunder, you should find a safe place to sit out the storm. Lightning can strike without warning as far as 10 miles away from the storm’s central location.




Live Calibration Of Map Images With MapCalibrator

Application Name: MapCalibrator

Description: Geocalibrates a map image using GPS positions, then plots your current position.

Publisher’s website: None

Cost: Free

Version/date reviewed: v.1.06  /  7-20-11

Phone/OS: Droid X / Android 2.3

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Android Market (mobile app only)
Android Market (browser)


There are lots of apps (e.g. Locus, OruxMaps) that let you take previously-calibrated map images and then view your location on them using your phone’s GPS. MapCalibrator is a bit different – you can take a map image, either download from external sources on your phone, or photographed using the camera, and then calibrate it using three live GPS positions. After calibration, you can then view your approximate position on the map.

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The program starts by asking you to select a map image for calibration. This can be a map picture you’ve uploaded to your camera, as with the topo map images above, or a photo you take with your phone’s camera. For example, you could take a photo of a trail from an info kiosk at the trailhead, then use the program to calibrate this map image.

I tried using map images in TIFF, GIF, PNG and JPG format. The TIFF format didn’t load at all into the program; the GIF and PNG formats loaded successfully, but I was unable to calibrate either of them. Only the JPG image worked correctly for me.

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When you reach a known point in “real space” for which there’s a corresponding point on the map, you can add a calibration point. Press the Menu button, then select “New Reference Point”. A blue circle will appear in the map display, and you tap-and-drag that blue circle so that the center dot is on your current position. This can be a bit tricky, as your finger will cover the blue circle as you drag it, making it difficult to place accurately. The GPS is also not on continuously, so you’ll need to stand in one spot for about 15 seconds or so before calibrating, to make sure the program has your current position accurately.

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Once you have the calibraiion point set, press Menu = Use Reference Point to save that calibration point. Your GPS coordinates are entered automatically, but if you have more accurate coordinates from a map or another GPS, you can enter them manually in degrees:decimal minutes format.

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You’ll need to enter three calibration points in order to complete the calibration process. You can add additional points, but they won’t be used (though the program’s author indicates he might add the ability to use additional points in the future).

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Once calibrated, your current GPS position is plotted as a red circle/dot on the map image. The GPS updates about every 15 seconds or so, so the position won’t always be up-to-date. In my tests, the calibration was pretty good, although the GPS position would sometimes jump to an offset position, then jump back again to an accurate position.

Other issues: The program doesn’t let you save image calibrations for future use, which is a big drawback; that means you’ll have to calibrate an image every time you want to use it. You should also remember that some maps are “schematic” in nature, i.e. scale, distance and direction may not be depicted with complete accuracy; such maps will be virtually impossible to calibrate accurately. You should try to use three calibration points that are spaced reasonably widely for the best results; if the points are too close together, the calibration is likely to be less accurate.

Final thoughts:  In most cases, you’d usually be better off using apps like Locus or OruxMaps that allow you to use both online maps sources and your own calibrated maps. However, for those instances where the only map available is one posted on a bulletin board or info kiosk, MapCalibrator is a useful tool to have.




Map Lightning Strikes With Thunderhunter

Application Name: ThunderHunter

Description: Map the approximate position of live lightning strikes.

Publisher’s website: ThunderHunter

Cost: Free

Version/date reviewed: v.1.2  /  7-17-11

Phone/OS: Droid X / Android 2.3

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Android Market (mobile app only)
Android Market (browser)


It’s monsoon season again in Arizona, which means thunderstorms more days than not. You probably know the standard method for estimating how far away a lightning strike is: start counting seconds as soon as you see the lightning flash, stop when you hear the thunder, then divide the number of seconds by 5 to find out how far away the lightning strike was in miles. ThunderHunter automates that process, and adds a twist: if you point your phone in the direction of the lightning flash, it will plot the approximate location of the strike in Google Maps.

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Starting up the app brings you this display. The compass at upper left shows the magnetic direction your phone is pointing in, the “?”  at upper right brings up very minimal help. When you see lightning flash, turn your phone quickly to face in the direction of the lightning, and tap the “eye/lightning” button.

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The button will change to an “ear” icon; when you hear the thunder from the lightning flash, press the button.

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You’ll get an estimate of the distance from the lightning strike in km and miles. Tap on the yellow arrow at lower left to go back to the lightning recording screen; tap on the map …

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… and the app will fire up the GPS to get your current position, then plot the approximate position of the lightning strike, along with your current position (the little green man).

Other issues: Most times, the app will determine direction based on which way the phone is pointing when you hear the thunder. So you can hit the “eye” button when you see a flash in any direction, have time to point the phone at the direction of the flash, then press the “ear” button when you hear the thunder to get an accurate time and direction. On a few occasions, thought, that didn’t seem to work correctly, and it took the direction the phone was facing when the “eye” button was pressed.

Final thoughts: Nifty little app that gives you an approximate distance and location for lightning strikes. Best used indoors at a window, though, since if you can hear thunder and see lightning, you really shouldn’t be outside.




Record And Map Compass Directions With AZ-Droid

Application Name: AZ-Droid

Description: Records, saves and plots the direction (azimuth)your phone is facing in.

Publisher’s website: None

Cost: Free

Version/date reviewed: v.1.1.0  /  7-6-11

Phone/OS: Droid X / Android 2.3

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Android Market (mobile app only)
Android Market (browser)


Point your phone at an object, press a button, and AZ-Droid will record your current GPS location, and the direction the phone is pointing. It will optionally plot that direction as a line in Google Maps, and save it for future use.

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Start up the app, and then wait for a GPS fix to be obtained. Once ready, tap either of the Capture buttons to acquire data.

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Date, time, azimuth (direction the phone is pointed in), and the latitude/longitude of the phone’s current location is saved.

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Select “Map Azimuth”, and your current location is plotted with a dot, with the azimuth direction plotted as a line. You can adjust the length of the line in settings, but even the shortest line spans a very long distance, and you’ll have to zoom out a lot to see the end of it.

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If you “Save Azimuth”, the data is stored in a list, accessible with the “Manage Saved Data” menu item. You can select any or all of the saved azimuths, and plot them on a map, with the “Map Selected” menu item.

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The color, size and position of the plotted lines and comments can be adjusted in the Settings section.

Other thoughts: There’s no data export option, which is a big drawback; you’ll have to copy the data down by hand. And it would be nice to have the option to set a shorter azimuth line length on screen.

Final thoughts: I can think of a couple of uses for this app. Point it towards an unidentified landmark in the distance, then see on the map plot what the landmark might be. Take azimuths from two different locations, and see where they intersect, to better pin down the location of a distant landmark accurately. But if all you want is to record direction and current location, Snaptic’s Compass app might be a better choice.




Maverick: A Basic GPS Map Application

Application Name: Maverick

Description: Basic GPS mapp app

Publisher’s website: Code Section

Cost: Free lite version limited to 5 waypoints and one track;$5.95 Pro version removes those limitations.

Version/date reviewed: v.1.6.1  /  7-5-11

Phone/OS: Droid X / Android 2.3

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Android Market (mobile app only)
Android Market (browser)


It’s nice to have GPS map apps with lots of features and capabilities, but these massive feature sets can sometimes make these apps harder to learn and use. Maverick has a somewhat more limited feature set compared to other GPS map apps, but its streamlined feature set makes it very fast, and easy to use.

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Default view when you start up is your current position, displayed in a Google Maps interface. Other map options include Google Satellite/Hybrid/Terrain, Bing Maps/Satellite/Hybrid, Wikimapia and Nokia/Ovi maps, accessible with the “Maps” button at upper left; you can also convert your own maps into a compatible format with the paid mapc2mapc utility. Online maps are cached for viewing when you’re out of network range. The zoom buttons (and zoom level) are conveniently located at the upper right, and are an improvement over the default zoom buttons for Google Maps.

The blue triangle represents the field of view ahead of you, as determined by the compass on your GPS. Unfortunately, this uses magnetic direction instead of true direction, so it can be a bit off (11 degrees for my location); I wish app writers would always use Google’s built-in function for correcting for magnetic declination.

If you scroll the map by dragging, a blue arrow will show up at left (visible above); tapping on that will bring you back to your current GPS location. This is a nice implementation of this feature.

Tapping on the icons below brings up a number of additional screen options.

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The Binoculars icon brings up a search screen.

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The green flag icon puts a waypoint at the center of the screen; it also changes into a pencil icon, which you tap to bring up the waypoint editing screen above. Waypoints are saved in KML format, and can be exported for use in Google Earth and other apps.

The “yellow” checkered icon turns GPS on and off, while the icon at lower right turn GPS track recording on and off; you can also turn on track management using the Menu button. The button at lower left toggles between Map mode (the default) and access to three alternate data screens:

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Compass view shows the direction your phone is pointing in; if you have a waypoint set as a destination (as above), it also shows you the direction to travel in to reach that waypoint, and the distance to that waypoint.

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The time/track data screen lets you start recording a track, and the total time/distance/average speed along that track. If you have an account at GPSies.com, you can upload the track there.

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The final screen is a GPS info screen. Tapping on any of the data screens lets you choose between twenty different datasets for that screen (e.g. UTM coordinates, sunset, ETT, etc.), offering more flexibility in data display than other similar apps.

Final thoughts: Nice, clean, fast, simple GPS mapping app. The free version is definitely worth a look. However, I think the paid version is a bit overpriced at $5.95; apps like Locus and OruxMaps offer larger feature sets at a similar or lower price.




LightSquared And The FCC – Still Doing Their Best To Destroy GPS

Cross-posted at Free Geography Tools

Back in February, I had a long post about the FCC’s conditional approval of LightSquared’s wireless broadband proposal. This waiver was vigorously opposed by the GPS industry because tests by Garmin showed that it would seriously disrupt GPS in areas where it was implemented. Read the post for a full rundown, but briefly LightSquared’s plan requires high-power transmissions in frequencies immediately adjacent to the GPS band, which drown out the GPS signal entirely. LightSquared dismissed these Garmin results, stating in a comment to my post:

… the Garmin tests that you refer to were not made under appropriate circumstances so the results are not accurate indications of how our network will perform. To get a real examination of the situation, tests must be conducted in the proper band and with the right filters. We’re now engaging in testing supported by the government and being done with the cooperation of many in the GPS community. We believe that this process will produce the most reliable results and will show that our network and GPS can coexist.

The FCC’s conditional waiver required LightSquared to form a study group with the GPS community to measure and analyze the potential effects of their broadband transmissions on GPS, and report back to the FCC by June 15th, 2011. Concurrently, the government’s National Executive Committee for Space-Based PNT (Position Navigation and Timing) asked a governmental interagency committee (National Space-Based PNT Systems Engineering Forum (NPEF)) to do its own separate, independent measurements to analyze LightSquared’s proposal, and also report their results in June of 2011.

Well, both reports are officially in, but enough results leaked out earlier to make their conclusions no surprise – the LightSquared system as originally described would completely disable the GPS system everywhere in the vicinity of a LightSquared transmitter, including applications for aviation, transportation, high-precision surveying, space, and consumer uses. This was the conclusion of both the LightSquared report, and the NPEF report. While the GPS industry and LightSquared were unable to agree on common wording for most of their conclusions, even LightSquared acknowledged that they were completely wrong in their original conclusion that “our network and GPS can coexist”.

End of story, right? Not quite. The original due date for the LightSquared report was June 15th, but they got a two-week extension from the FCC, apparently to give them time to come up with an alternative proposal that they claim fixes all relevant problems. It essentially consists of two major modifications to their original proposal:

1. Cut the maximum power transmission levels by 50%.

2. Not using 10 MHz of bandwidth closest to the GPS bands, and accelerating plans to use an additional 10 MHz further away, originally intended for service expansion in the future. LightSquared claims that 99.5% of GPS receivers would be free of interference from their transmissions.

The GPS community calls this a “Hail Mary” plan, and with good reason:

Cutting the maximum power transmission level by 50% is no cut at all (Source)

The FCC gave LightSquared approval to transmit at a maximum power of 15,850 watts, but LightSquared stated that its maximum operating power would be 1600 watts, 10% of the maximum. Cutting the “maximum power transmission level” drops that number to 8,000 watts, but unless the operating power is also cut by half, that will make no difference for GPS interference. LightSquared is unlikely to cut that power level in half, as that would require them to construct 4x as many transmitters as originally planned, increasing costs substantially.

“Giving up” 10 MHz of bandwidth may still incapacitate all GPS receivers, and definitely incapacitates all high-precision receivers.

As the GPS community’s rebuttal points out, LightSquared’s conclusion that their revised proposal will eliminate interference for 99.5% of current GPS units isn’t supported by the report they submitted to the FCC. Since LightSquared sprang their proposal at the last minute, without consulting with the GPS industry, most of the tests did not incorporate LightSquared’s new operating conditions. But those that did indicated substantial “harmful interference” to about two-thirds of GPS receivers in the general navigation category (meaning automotive receivers). In order for LightSquared to prove that their revised proposal wouldn’t have harmful effects to the vast majority of GPS devices, the tests would have to be repeated using the conditions of their revised proposal.

What’s more, the NPEF report indicates that several aspects of test conditions used in the LightSquared report tests may have resulted in underestimating the negative effects of LightSquared’s transmissions:

  • The broadcast power level for the LightSquared transmitters was actually lower than that planned for operational use. While the interference results were supposedly compensated for this based on simple distance/power calculations, the NPEF report stated that some interference effects could not be adequately compensated for using such a simple compensation.
  • Tests were done using just a single transmitter, but heavily-populated urban areas would require multiple transmitters, each of which could interfere with a GPS receiver. While modeling could be done to simulate these effects, accurate assessment of these effects would require testing with multiple transmitters.
  • Finally, the LightSquared receivers also broadcast in a frequency range adjacent to the GPS band, albeit a different frequency and lower power than their main towers. It’s possible that these receiver units might also interfere with the GPS signal, but since LightSquared still doesn’t have any of these receivers available for testing, it wasn’t possible to assess what harmful interference they might generate.

As an additional “bonus”, this 10 MHz “surrender” by LightSquared is only temporary – they plan to use that frequency space in the future for service expansion, which would once again, by their own admission, disable GPS receivers completely anywhere within the vicinity of a transmitter.

What’s more, LightSquared freely admits that the vast majority of high-precision GPS units, those used for “agriculture, aviation, construction, engineering, surveying, marine navigation and disaster monitoring as well as federal, state and local government uses”, would be rendered unusable even under their revised proposal. Their solution? Make the GPS industry, and users of those high-precision GPS units, pay to fix the problem themselves. Why and how? Simple:

Paint the GPS industry as mooching off the government

LightSquared commissioned a report from the Brattle Group concluding that GPS satellite transmissions from the government-run GPS program amounted to an implicit $18 billion dollar subsidy of the GPS industry, and that the GPS industry should therefore pick up the tab for any equipment modifications required to co-exist with LightSquared. Seriously? Don’t you know anything about the history and rationale behind GPS?

  • It was originally intended for military use, a function it still fulfills today. The incremental cost for consumer/industry use is trivial in comparison to the total costs.
  • After KAL Flight 007 was shot down by the Russians in 1983, President Reagan issued a policy directive that required the low-precision (Selective Availability) GPS signal to be made freely available for civilian use.
  • In 1996, President Clinton issued a policy directive that GPS officially be declared a dual-use (civilian and military system), and in 2000 that Selective Availability be turned off, making moderate to high-precision GPS signals available to everyone.
  • In 2004, President Bush issued an policy directive that no direct user fees be charged for GPS signals.

But now LightSquared, a commercial initiative that played no part in the development of GPS, feels it has the right to imply that the GPS community needs to shoulder the costs of their proposal? Please.

Accuse the GPS industry of being aware of this possibility, and not designing their equipment to be ready.

LightSquared claims that the GPS industry has known for years that terrestrial transmissions in adjacent frequency bands were coming, but did nothing to either fight them, or re-design their equipment to handle interference from these transmissions. Putting it mildly, this is a total crock. As Trimble’s response to these statements makes clear, these terrestrial transmissions were supposed to be “ancillary”, auxiliary low-power transmissions in limited areas where terrain or foliage blocked reception of the primary low-power satellite transmissions; the GPS industry acknowledged that it could live with such limited low-power terrestrial transmissions. The waiver granted by the FCC to LightSquared flipped this around completely, making the terrestrial component the primary one, and jacking up the transmissions power level by orders of magnitude. Unless the GPS industry had Nostradamus on the payroll, and he could have foretold that the FCC would completely reverse its position on broadcast power levels in these bands, it’s ridiculous to imply that the GPS industry knew this was coming.

Claim that fixing the issue is easy and cheap

LightSquared claims that cost of fixing a GPS receiver was trivially low, on the order of 5 cents for a basic filter, but that the GPS industry wasn’t willing to implement this fix. First off, LightSquared’s technical competence to make such statements is highly suspect, in light of their original position that their system would have no detrimental effect on GPS. Secondly, they are unable (or unwilling) to provide a demonstration GPS unit that incorporates these filters, merely relying on a chip manufacturer’s assertion that they could provide such filters; if it’s so easy and cheap, why can’t they prove it? The GPS industry, with far more experience, doesn’t think such a solution is trivial. The NPEF government report goes even further:

… add-on filtering solutions are not viable for a significant fraction of fielded equipment due to considerations such as performance (signal attenuation, increased thermal noise floor, phase and group delay variations with temperature and between frequencies, loss of narrow correlator benefits), cost, size, and weight.

For a new product, many additional degrees of freedom are opened for mitigation techniques… Unfortunately, redesign is not likely to result in the same level of performance provided by current receivers, especially those employing wide RF front-end passbands… High-precision equipment is among the most difficult to protect against the LightSquared emissions since these receivers typically process wideband GPS signals that require a wideband receiver passband and such equipment usually also has severe differential group delay requirements. For these types of receivers, filtering can typically significantly degrade or even destroy the very information required for the most demanding scientific and precision applications.

In its report, the NPEF concludes that the problems with the LightSquared proposal are so serious and intractable that they recommend:

  • The FCC immediately rescind the conditional waiver granted to LightSquared in January 2011, which would effectively put LightSquared’s planned system on hold
  • Six months of more rigorous tests of the possible effects of the LightSquared system on GPS, and make future decisions based on those results
  • The FCC determine whether any broadband system that relies on frequency bands adjacent to GPS could be implemented without interfering with GPS, and adjust their regulations accordingly if the answer is “no”.

In a sane and rational world, the FCC would adopt these recommendations immediately. But in a sane and rational world, they would never have granted LightSquared a waiver in the first place, even a conditional one. They’ve been tasked by the Obama Administration with freeing up frequency space for broadband, and they seem committed to that goal regardless of the facts. They’ve already shown their bias toward LightSquared (and against the GPS community) a number of ways:

 

A 30-day comment period now runs through the end of July, with a final decision due August 15th. Based on their past history, I would assume that the FCC will extend their conditional waiver, with possibly a requirement for a few more months of testing. And if the results of  testing shows that the main impact is on high-precision GPS receivers, my gut feeling is that they will grant final approval to LightSquared, and dump the responsibility and cost for “fixing” high-precision GPS receivers on the manufacturers and users. LightSquared apparently feels the same way, as they’ve announced that they’re going to start construction of their network right away, even before the final FCC decision is made.

But it’s my hope that other government bodies will step in to stop this process, and I have to believe they will. Since the waiver was granted in January, this issue has gotten more and more attention from affected industries, elected government officials, and the press. An amendment has already been attached by the House Appropriations Committee to a budget bill, prohibiting the FCC from spending any money or resources on the LightSquared proposal until they prove that it won’t interfere with the GPS system. If the FCC actually approves LightSquared’s plan, I think it’s likely that legislation will be passed quickly to override their decision. Apart from the FCC (and possibly the White House), there isn’t a single government agency that thinks this is a good idea. The Save Our GPS coalition has a growing list of GPS-dependent companies, from a wide variety of industries with substantial political influence, joined in opposition to the LightSquared proposal . In particular, I expect that any Senator or Representative from a farm state is a solid vote in opposition to LightSquared, given how important GPS is in modern industrial farmin. The powerful telecom lobby is aslo in full opposition, partially because of the potential for competition, and partially because LightSquared used loopholes and political influence to gain access to wireless bandwidth for far less than what the telecoms had to pay in open auction. LightSquared has very few friends in Washington, and a lot of opponents; ultimately, I’m optimistic that GPS will be saved.




Location Coordinates (Plus Reverse Geocoding?) With GeoPicker

Application Name: GeoPicker

Description: Gives you latitude/longitude coordinates for a selected point, plus supposedly reverse geocoding (address from coordinates/position).

Publisher’s website: Android Life

Cost: Free

Version/date reviewed: v.1.2  /  6-25-11

Phone/OS: Droid X / Android 2.3

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Android Market (mobile app only)
Android Market (browser)


GeoPicker is a simple, easy-to-use geographic utility for determine latitude/longitude coordinates for a location. It also may have a killer feature for most of you: reverse geocoding for a point (address from coordinate position). But more on this in a bit …

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App fires up the GPS automatically, but defaults to a position in the middle of the US.

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Select “My Location” from the menu to go to your current GPS location. Tapping on the coordinate display toggles between degrees-minutes-seconds (boo) and decimal degrees (yay). As in standard Google Maps, pinch to zoom, or tap on the map and use the +/- zoom controls; touch and drag to scroll.

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As you scroll, a red “X” appears under the final pin location. Stop scrolling and …

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… the pin drops into location.

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From the app Menu, you can copy the current coordinates into your phone’s clipboard, for pasting into another app. Other options include getting driving directions from your current position to the selected point, toggling between Google Maps/Satellite views, and searching for landmarks and addresses.

The app also has an option for telling you what the nearest address to the current pin location is (reverse geocoding), but unfortunately this caused my Droid X to force-close the app every time. From the App Market comments, this appears to be a common problem with Motorola Droid phones; other phones may not have this issue. You can do something similar in Google Maps, albeit with less precision – a long press on a location in Google Maps will bring up the closest address to the selected location as a pop-up balloon. Tapping on that popup balloon will take you to a page with additional options like directions, Street View, and local search. However, there’s no crosshair for positioning in Google Maps, so you have to zoom in very close to be able to place your finger in the right spot.

Final thoughts: Handy utility for picking up arbitrary position coordinates, especially if you need to copy/paste them into another app. If the reverse geocoding works for you, that’s an added bonus.




Measure Distances, Get Elevation Profiles With Survey

Application Name: Survey

Description: Distance and elevation profile tool

Publisher’s website: sys-irap

Cost: Free (ad-supported)

Version/date reviewed: v.0.7.3  /  6-23-11

Phone/OS: Droid X / Android 2.3

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Android Market (mobile app only)
Android Market (browser)


The Survey app is an odd mix of different functions, some of which work well and are useful, others less so.

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Start up the app, and get three options: Measure, Short distance, and Long distance.

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“Measure” brings up the view from your camera (not visible in the screenshot above), along with a graduated on-screen scale and slider. The idea here is that if you know the distance to an object, you can set it using the slider, and the scale will adjust to measure the true size. Not really sure how useful this is, as it only works out to a distance of 5 meters max, and fairly small sizes. Seems to me it would be easier just to pull out a tape measure.

short_distance

The “Short distance” option brings up another camera view, and a superimposed ground line (red) and ground mesh. The idea here is that if you’ve entered the camera’s height above the ground in the Settings section, and if you put the ground line at the base of an object at the same ground level as you, you can determine the distance to the object, and use the vertical scale to determine the height. It works, sort of, but only to about a distance of 75-80 meters, and not very accurately at that. The Smart Measure app works in a similar fashion, but is easier to use and is marginally more accurate.

survey_1

 

The “Long distance” function is substantially more useful. Select this option, and you’ll get a Google Maps view with your current GPS location plotted as a base location. You can tap and drag this icon to set a different base location; unfortunately, there doesn’t seem to be an easy way to reset it to your current GPS location without backing out of this screen. The icon control at top left toggle between Google Maps/Satellite views (right icon), while the one at right centers the view on the current base location.

survey_2

A long press on a different location on the map creates a “survey point” at that location, marked with a camera icon. Press the “Survey” button at the bottom …

survey_3

… and get coordinates/elevations for base location and survey point, and the distance from the base point to the survey point. “G.H.” stands for “ground height”, and is determined by GPS for the base location, and always set to 0 for the survey point. You can adjust the ground height for either location with the button controls to the right.

point1

Tap on the camera icon, and get an augmented reality view through your camera, with the arrow telling you which direction you need to rotate the camera to have it oriented towards the survey point.

point2

When oriented correctly, the survey point will show up as a blue dot, labeled with the distance.

profile

Tap the other icon from the map screen, and get a plot of elevation from the base location to the survey point in orange. It’s not clear from the app what the green and red lines are; I believe they’re elevation plots and direct point-to-point sight lines that include the curvature of the earth’s surface, but I’m not sure.

Other issues: This app really needs better documentation; it’s not entirely clear how some of these functions work. The app description also implies that you can take geotagged camera shots of various screen views, but I couldn’t figure out how to get that to work.

Final thoughts: There’s the kernel of a good app here, and it’s worth taking a look at. But I prefer Smart Measure for distance/height measurements, and AltitudeProfiler for elevation profiles (though the latter has data download limits).