Enterprise Solutions
Tracking Trees With Pocket PCs in Colombia by Stalin Fernández and Juan Manuel Cardona
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orest engineers perform a variety of tasks, including timber inventory in planted forest or rain forest, urban tree mapping and management, and keeping track of log pieces in sawmills and lumberyards. In all these tasks, Pocket PCs can noticeably boost efficiency, and minimize potential mistakes when entering the data into tally sheets or field notebooks, enabling the timely processing and use of gathered data. Silvano Ltd. is a Colombia-based company specialized in consulting services in forestry. Our main line of work is forest measurement. One of the biggest tasks we perform during the year is the inventory of 70,000 acres of planted pine and eucalypt forests owned by a prominent paper manufacturing company. Until last year we collected data from sample plots set on tree stands scheduled for next year’s felling with paper tally sheets. The plantations are scattered over five different states around the country, and we had to establish 600-800 plots during two months of field work, twice a year. This left us with the daunting task of handtyping information from 600 sheets filled with numbers and tree attributes into Access or Excel. We had to do this ourselves because of the tight requirements from our customer; we couldn’t simply hire a typist. What made the data entry task even bigger was that, with paper forms, poor handwriting was a huge headache. Weeks after the fact (and without the person who created the initial tally sheet available), we had to decipher every last number and note. After two months of walking up and down mountains, dripping wet from head to toe most of the time, strolling for hours each day along muddy roads and working six days a week, 16 hours a day, we didn’t look forward to returning to our city office knowing that a ream of paper was waiting there for us. After four years of this, four months a year, we definitely had to find another way—and we did. We usually field five measurement teams. Each is led by a forester, who in turn is aided by two additional people: one helps clear the way under the thick underbrush until the team gets to the previously designated coordinates for the plot, and then helps to paint the tree numbers. Another person, the annotator, carries a clipboard, and he/she is the one who writes down the numbers and features of the trees we measure. We record two main variables, the tree diameter at chest height and the tree height. However, each tree has up to 20 attributes, in-
(Above) A measurement team at work. (Right) Entering tree data into the Pocket PC. (Bottom Right) A shrink-wrapped iPAQ in the forest. cluding stand ID, plot number, understory condition, plot area, slope, etc.; these all have to be entered into the field book/tally sheet. Last year two of the teams carried Pocket PCs with them, so the data entry could be done electronically alongside the old paper system. We had developed a version of a data-collecting form for the Pocket PC, including all the fields found on the paper tally sheets. We named it the Digi-Tally Paperless system. Our main concern was to find out if the annotator, who is frequently from the country, and who in most cases is a teenager with schooling often limited to fifth grade and with no previous experience with computers whatsoever, could handle the job of entering the data into the Pocket PC. We were pleasantly surprised to find out that they, though a bit reluctant at first, easily adapted to using the devices. Now each team comes back every night and uploads the *.cdb files Digi-Tally generates into a laptop, which in turn converts them to Access so we can crunch numbers and find stand timber volume and the other information we’re paid to determine. The system has five tabs which allow the user to enter data and make calculations on the fly. It’s also programmed to show warnings if there is missing or inconsistent data —like fields inadvertently left blank, impossible measures (such as a tree with a chest-height diameter of 5 inches and
a height of 100 feet), or misspellings on stand IDs, etc. Tree heights are also calculated instantaneously, so the user can keep track of the consistency and logic of his or her work. Another concern we had was how rugged the Pocket PCs really were. Rugged field devices such as the TDS Recon, or the rugged cases offered by Otterbox, were just too expensive for our test, so we worked with the two iPAQs we already had, an h1940 and an h2215. We carried them along with us into the woods for two months. We used them in misty environments, and under improvised tents made with plastic sheets during heavy rains. They Juan Manuel Cardona and Stalin Fernández are Forest engineers, and run Silvano, Ltd. in Caldas (Antioquia), Colombia. Information on their company can be found at www. silvanoforestal.com/index-e.html. They can be reached at silvano@silvanoforestal.com. Sep 2005
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Enterprise Solutions
Tracking Trees with Pocket PCs in Colombia
Developing the Digi-Tally
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he Digi-Tally Paperless solution was developed in eVB (Embedded Visual Basic), and with Odyssey’s Dataviewer control. The Paperless system took about six months to create from start to finish. We found that the testing stage took up most of the development time. Now to a brief explanation of our Paperless system of field data collecting: The first tab allows us to enter the instruments the plot is going to be measured with, as well as the name of the forester who’s doing all the measurements. The second tab is used to enter the plot attributes. After filling
First tab defines the measurement instruments and the name of the Forester.
Plot attributes entered in the second tab. Tree attributes in the third.
this in, you tap the second button to create the database for the 24UNION tree farm. The third tab is the most important, because it is where most of the data is entered. Diameter at chest height, as well as the four measurements needed to calculate tree height (h_Obs) are entered. Tree features such as crown position etc., are also entered here. Note the check box next to the diameter (DBH) field. When the third icon is pressed, the form is cleared and a consecutive tree number is added and ready to be described. In the fourth tab we can check the status of the data we just entered. Operations such as record editing, deleting or searching can also be performed here. In the fifth and final tab additional remarks were operated by people not used to handling delicate devices. One of them was protected from rain drops and dusty roads with a shrinkwrap covering, which left only the power slot uncovered. The other iPAQ was carried in a simple case with a small amount of silica gel at the bottom, in the chest pocket of my utility vest. Both machines survived the experience unscathed and without data loss (just to be sure, we copied our data to SD cards in each device). One thing we found is that battery life must be carefully monitored: we found that the 46
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about the plot are entered, if deemed necessary. Since most of the staff we work with in the field feel intimidated when faced with a computer, we decided not to use dropdown menus, but icons, which we found are a lot easier for them to understand. The first icon opens existing databases after selecting them from the “Finca” field. The second creates new plots or new databases. The red buttons are used to browse through the database. The blue button is used to browse through records of trees marked with the checkbox next to the diameter field, which are the ones that were chosen for height measurement. Not all the trees from the plot are measured; only a sub-sample of them.
Sep 2005
Error checking is done in the fourth tab.
Icons are much easier for our hired help to learn to use to navigate through the Digi-Tally functions.
The fifth tab allows the input of additional comments on the plot.
We use a similar application to monitor urban tree health for our customers from town parks, cities and neighborhoods. We have also developed a small applet that allows us to calculate rectangular plot closure, area, and angle and azimuth corrections. It draws a sketch of the plot so that the user can pinpoint any mistakes on-site, something that previously required painstaking hours of typing and data checking on a spreadsheet. The Pocket PC has literally saved us from the mountains of paperwork we had to deal with before.
h1940 ran out of juice quickly. This year we are planning to test how a Bluetooth GPS will perform in our working conditions: under a thick canopy and on cloudy days, and how much this will drain the battery of our devices. We need to see if it pays to develop forestry-oriented applications that include GPS functionality. Our tests have been successful; we’ve saved endless hours of data entry, and improved the accuracy of the information we submit to the firms that hire us. We’ve had to improvise to
protect our non-rugged devices in the field from the elements and from the rough terrain in which they’re used. We’ve also been pleased at how inexperienced workers with minimal education have been able to learn and use the Pocket PCs and the software we’ve developed for them. Overall, we’ve found that with a little care and some careful software development, the Pocket PC can revolutionize forestry work amidst the wilds of Colombia. n