We've been trying to put off georeferencing for as long as we can, but as Nanthinee said she was coming over on Tues, 15/5/07 to check on our progress, eventually we had to set our minds to the task.
By the way, when I talk about georeferencing, I mean 'find the coordinates of the location of this specific place on the Earth'. The two coordinates needed are the longitude (point on horizontal line) and latitude (point on vertical line). Longitude and latitude are measured in different ways, Google earth uses degrees/min/sec. I'm sorry for all the layman language but it's the easiest way I can explain.
So we started, and encounted problems.
Macritchie area, Thomson Ridge, on trail
So you thought the 'on trail' is insignificant right? That's what we thought too. And so we found the coordinates for Thomson Ridge. Which is entirely wrong! We should have georeferenced the trail beside Thomson Ridge!
Woodcutter's trail
Where the hell is it? Huh? We spent 1hr searching online for map of the trail. And we couldn't find it. Oh yea so we gleaned from various online sources that it starts near Dairy Farm Estate and ends near Upper Pierce Reservoir, but it didn't help in the georeferencing, at all.
Rifle Range Road, lamppost 95
Of course we couldn't find the exact location of a lamppost on any map. So we georeferenced the entire road by taking the midpoint. Which creates a large error as this particular road is very long.
So in the end, first attempt at georeferencing = failure :(
Showing posts with label localities. Show all posts
Showing posts with label localities. Show all posts
Wednesday, 16 May 2007
Thursday, 10 May 2007
Geo-referencing
Geo-referencing was one of the alien terms introduced to me. Thankfully for Nanthinee, who is going to be a graduate student at NUS this coming semester, I've finally grasped a rough idea on what geo-referencing is all about.
In order to understand geo-referencing, one must know what HerpNET is first. Basically, natural history museums around the world are collating the collection of the study of reptiles and amphibians by bringing together knowledge from world wide museums to generate a database of these herpetological collections. This will facilitate understanding and ultimately conservation as this database has a great wealth of knowledge from all corners of the world. In fact, it being accessible via various portals makes it a great online tool for research too. All that said and more to be found at the above link.
Finding coordinates to the localities that are provided is what geo-referencing is about in just a few words. The larger picture behind it includes a whole lot of map reading techniques that no geography teacher has ever come close to introducing me. I thought it was really nice of Nanthinee to sit down patiently and explain things one by one, if I must say, painstakingly. Well at least now my knowledge of maps extends beyond just scales and contours to triangulation points, datum and projection. One interesting item was projection. Maps being a 2-D depiction of a 3-D Earth never crossed my mind once till she explained; making me realise the many simple things in life that I've taken granted for.
Also, learning how to express coordinates was totally fresh. I never knew they were measured in degrees, minutes and seconds. That level of measurement had always seemed to me like morse codes and now that I've got it right, I thought I could be on my way to geo-referencing. Yet, I could not be more wrong.
Sheets of Excel spreadsheets were opened relentlessly, displaying laborious work done by November, Grace and Nanthinee. The overwhelming number of columns were daunting. Fortunately, once again for Nanthinee, she went through each part and made it easier to see through the bulk and realise the intricate organisation of the data.
Throughout the entire tutorial, I have to say almost 50% made not much sense to me. I have to admit I'm bad at map reading, but Nanthinee made it seem almost like a breeze. She whipped us to the map room which was located along a corridor I used to wander along during term time, and yet still fail to notice it. There, we met Sarkina who will be seeing us and assisting us a lot in getting the relevent maps. Once she pulled out several maps, Nanthinee got down to a simple demonstration on how to read scales and deriving coordinates.
Although I can now give coordinates to a localities given a map and a ruler, it still remains fuzzy about doing the actual geo-referencing. I guess learning skills in life is not enough. To etch it in our brains, the application of the skill is essential. That'd be for another blog entry to come.
In order to understand geo-referencing, one must know what HerpNET is first. Basically, natural history museums around the world are collating the collection of the study of reptiles and amphibians by bringing together knowledge from world wide museums to generate a database of these herpetological collections. This will facilitate understanding and ultimately conservation as this database has a great wealth of knowledge from all corners of the world. In fact, it being accessible via various portals makes it a great online tool for research too. All that said and more to be found at the above link.
Finding coordinates to the localities that are provided is what geo-referencing is about in just a few words. The larger picture behind it includes a whole lot of map reading techniques that no geography teacher has ever come close to introducing me. I thought it was really nice of Nanthinee to sit down patiently and explain things one by one, if I must say, painstakingly. Well at least now my knowledge of maps extends beyond just scales and contours to triangulation points, datum and projection. One interesting item was projection. Maps being a 2-D depiction of a 3-D Earth never crossed my mind once till she explained; making me realise the many simple things in life that I've taken granted for.
Also, learning how to express coordinates was totally fresh. I never knew they were measured in degrees, minutes and seconds. That level of measurement had always seemed to me like morse codes and now that I've got it right, I thought I could be on my way to geo-referencing. Yet, I could not be more wrong.
Sheets of Excel spreadsheets were opened relentlessly, displaying laborious work done by November, Grace and Nanthinee. The overwhelming number of columns were daunting. Fortunately, once again for Nanthinee, she went through each part and made it easier to see through the bulk and realise the intricate organisation of the data.
Throughout the entire tutorial, I have to say almost 50% made not much sense to me. I have to admit I'm bad at map reading, but Nanthinee made it seem almost like a breeze. She whipped us to the map room which was located along a corridor I used to wander along during term time, and yet still fail to notice it. There, we met Sarkina who will be seeing us and assisting us a lot in getting the relevent maps. Once she pulled out several maps, Nanthinee got down to a simple demonstration on how to read scales and deriving coordinates.
Although I can now give coordinates to a localities given a map and a ruler, it still remains fuzzy about doing the actual geo-referencing. I guess learning skills in life is not enough. To etch it in our brains, the application of the skill is essential. That'd be for another blog entry to come.
Subscribe to:
Posts (Atom)
