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Archive for the 'measurement' Category

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.

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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.

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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 …

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… 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.

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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).




Range Circles In A Google Maps View With CircleMap

Application Name: CircleMap

Description: Draws range circles in a Google Maps view

Publisher’s website: pscdroid

Cost: Free (ad-supported)

Version/date reviewed: v.1.1.4  /  6-14-11

Phone/OS: Droid X / Android 2.2

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


CircleMap draws a set of concentric range circles on top of a Google Maps interface.

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The initial view shows a wide-area zoom, with constant distance circles centered on your current location. Use pinch-to-zoom to zoom in and out, or tap on the screen, and +/- zoom controls will appear at the bottom.

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As you zoom in, the distance spacing for circles changes to match the zoom; unfortunately, you have no control over the spacing. Your current location starts out in the center, but if you drag the map over, a distance measure (red line with distance in metric units) will show up, indicating the distance between your current location and the center point of the map.

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From the menu control, you can set a base location for measurement other than your current location by scrolling to the desired location and choosing “Set base point”. The “Current position” control puts your current GPS location at the center of the screen; if that’s not the current base point, choosing “Set base point” will make it so. Finally, “Change map” toggles between the standard Google Maps view and the satellite/hybrid view. The latter doesn’t work very well, as the range circles are drawn with such thin red lines that they’re difficult to see against some backgrounds.

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The pencil control in the lower-right-hand corner of the first three screenshots lets you draw freehand on the map, but the utility of this is marginal; it makes the range circles go away, and you can’t save your drawings. Tap on the double-arrow control to erase the drawing and go back to the range circles view.

Final thoughts: The only app of its kind that I could find on the market, and does a decent basic job. Would be a lot better if you had control over range circle spacing and units, and the thickness/color of the circle lines.




Survey-Relevant Data App For Android

Application Name: Survey Demo

Description: Data overlays useful to surveyors and map users.

Publisher’s website: Surveying.org

Cost: Free demo version; Standard ($4.95) and Pro ($9.95) versions add additional features.

Version/date reviewed: v.1.0  /  5-5-11

Phone/OS: Droid X / Android 2.2

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


The Surveying.Org website offers a host of useful data layers for surveyors and cartographers, but all of the layers don’t work in the standard Android browser. The suite of Survey apps (Demo, Standard and Pro) offer these same data layers in stand-alone apps. Data layers viewed in a Google Maps interface, with standard Road/Aerial/Terrain views or the MyTopo USGS topographic maps view, include:

UTM

UTM zone overlays (tap on the map for the info popup for all layers)

spcs

State Plane Coordinate System boundaries

meridians

Principal Meridian boundaries and locations for the Public Land Survey System

All of the above can be viewed with the free Demo version. The Standard version of Survey ($4.95) adds two more data layers, and an additional function:

  • National Geodetic Survey horizontal control benchmarks (with links to data sheets)
  • National Geodetic Survey vertical control points.
  • Measure distances and areas on the map.

The Pro version of Survey ($9.95) adds a few additional features:

  • Built-in inclinometer
  • Find the latitude/longitude for a point by tapping on it.
  • Recording of points and tracks, export in KML format.

Other issues: I guess I have a number of concerns with the app:

  • Data layers are fetched online as needed, but that means that if you’re offline, they’re not available – a big drawback
  • The GPS stays on if you switch to a different app, rather than exiting the main app; forget about this, and you can quickly drain down the battery.
  • The Standard version is a bit expensive ($4.95), but if you need that data handy, probably worth it. The current set of additional features with the Pro version doesn’t justify it’s $9.95 price, as you can duplicate the additional functionality with other apps, many of which are free. The author plans to add PLSS data and lat/long to State Plane Coordinate System coordinate conversion to a future version, which would make it more worthwhile, but still a bit expensive for what you get.

Final thoughts: All of the functionality of the Demo version can be gotten using the Surveying.org website in the standard Android browser, plus length and area measurement, but the interface is easier and faster in the app than the website. If you need a handy reference source in the field for nearby NGS benchmarks, the Standard version might be worth the high price, but if you can plan ahead, all the data is available for free at the Surveying.org website The Pro version is overpriced for what you currently get with it; until additional functionality is added, I’d pass on it for now.




Blow Things Up On Your Android Unit With Magnify

Application Name: Magnify

Description: Uses your camera view and digital zoom to magnify objects; option to record view with photo.

Publisher’s website: Appd Lab

Cost: Free (ad-supported)

Version/date reviewed: v.2.2  /  3-12-11

Phone/OS: Droid X / Android 2.2

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


I’ve tested several Android apps that take the camera input and magnify it, like Magnifying Glass, iMagnify and IDEAL Magnifier, but I’ve uninstalled all of them in favor of the app reviewed her, Magnify; it’s clearly the best of the bunch.

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My screen capture app doesn’t include the camera view; if it did, you’d see the camera input in the white area above. The four buttons, from left to right:

  • Camera icon: Takes a photo of what you can currently see in the camera view.
  • Eye icon: Re-focuses the image. The app documentation says that you need to have the camera lens at least four inches away from the object to focus. However, on my Droid X, with good lighting, I can sometimes focus even closer than that. If you move the phone towards/away from the object after focusing, you’ll need to re-focus.
  • Flash icon: If your camera has one, it turns on the LED flash to illuminate the object.
  • N icon: Converts the image to a negative; may improve detail visibility in some cases.

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On my Droid X, photos taken with the app are stored in the “Magnify” subfolder of the DCIM folder on the SD card, which is the default folder for camera pictures on my unit; may be different for your phone. The “white blob” at the bottom of the photo is glare from the LED flash illumination. One minor drawback is that the pixel size of the photo is limited; the original of the photo shown above is only 816 x 624. It would be nice to have an option to export photos at your camera’s full resolution. But this is a digital zoom, so you likely wouldn’t see any more detail.

Other issues: The ads look a bit incongruous at the bottom. But they’re well enough out of the way of the main interface to not be a major distraction, and they help keep the app free.

Final thoughts: Highly recommended; nice to be able to blow up views of small objects. Especially small type, useful for someone like me with aging eyes and reading glasses.




Measure Object Lengths With Smart Ruler

Application Name: Smart Ruler

Description: Measure lengths of objects placed on the Android unit’s screen

Publisher’s website: Android Boy

Cost: Free basic version; $0.99 Smart Ruler Pro version adds protractor, level, goniometer; $1.99 Smart Tools version combines apps from pro versions of Smart Measure, Smart Compass and Smart Ruler.

Version/date reviewed: v.1.1.3  /  12-21-10

Phone/OS: Droid X / Android 2.2

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


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Figure 1: This is a simple app that displays a scale on the screen, measurements increasing left to right; tap or tap/draganywhere on the screen to put a red marker line, and display the distance at that point. You can change units, font sizes and colors from the Settings menu. On my phone, distances were perfectly calibrated, but if you have a problem, you can manually enter a phone calibration distance into the Settings as well.

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Figure 2: Place an object flush against the left side, and tap/drag the red marker to the end of the object to measure its length.

Other issues: If you don’t have a screen protector, you run the risk of scratching the screen with the object. Even with tough Gorilla Glass, there are some objects (like rocks) that can scratch a screen.

Final thoughts:

Not much to say; does what it’s supposed to. The entire Smart line is pretty good (I’ve already reviewed a few others), and the $1.99 Smart Tools package, containing all these Smart measuring apps, is a bargain.