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kucai's diary

Recent diary entries

Mapping lake shore

Posted by kucai on 7 August 2016 in English (English)

I started refining the shore boundary of Lake Kenyir, reputedly the largest (or 2nd?, not sure, another lake is being filled up in Sarawak) in South east asia. Soon enough, I realized that there are jillions of coves that might need to be mapped, which brings the question of what's the acceptable level of fidelity when dealing with this kind of mapping. (this would certainly the case when mapping a country's shorelines too.)

I finally ended up using the 'triangle' method. 2 points at the jutting land ends of a cove (which is also called a point in bass fishing:) ) and 1 in the middle of the cove. If that is still too rough, add a point to either side of the middle point, which usually is good enough to show up as a cove in higher zoom renderings.

Oh well.. I probably need to visit these places with fishing gear.. you know.. verification purposes and all that. hah!

Location: Kuala Terengganu, Terengganu, Malaysia

Aligning hiway to Bing imagery

Posted by kucai on 30 December 2015 in English (English)

Just finished aligning the northern half of Jabor-Jerangau highway (about 50km) to newly available Bing imagery. Since the highway was originally created based on a gps track (I think), there was quite an offset between the gps track and Bing.

Also in some areas, it seemed that hiways on Mapbox imagery lay much closer to accumulated gps track than Bing, but that can possibly be attributed to the difference between coarse level 17 zoom to Bings level 18/19 color imagery. Bing is about 20-30 meters away from gps tracks.

I think I'll wait for more gps tracks before I offset the imagery. For now, I'll focus on making pretty highways...

Thank you Bing.. need moarrr...

Location: Jalan Jabor - Al-Muktafi Billah Shah, Kampung Landas, Terengganu, Malaysia

Potlatch editing

Posted by kucai on 16 December 2015 in English (English)

Crap, changeset creation error after 30 minutes tracing riverways in Paka

Rage... Fuuu*88

*damn, I always forget to save periodically even after I reminded myself to save periodically. And periodically, this happened

New sat image and alignments

Posted by kucai on 3 September 2015 in English (English)

Partially finished realigning buildings in Kota Bharu, Malaysia. It seems that a new sat image was available, and a mapper(s) traced the highways according to the new image but leaves the outline of buildings from older image intact. Therefore, those buildings have to be moved manually by selecting each one of them to align with the new image. (ignore lat long accuracy for the moment).

Perhaps, anyone who discovers an area with new sat image should first align existing hiways/buildings. Once the hiways/buildings matched with the new sat image, only then the sat image & hiways & buildings be offset to the accurate position. (can also be done the other way around, align the image to the existing highways/buildings, whichever is more accurate). That way we don't have to align things two or three times manually. (Anyway, anybody knows how big an area is offset when we realign a sat image? One tile, 10sqkm, whole state?)

Or perhaps, people should try not to accidentally realign the map (new mappers especially).

Central Kuala Lumpur

Posted by kucai on 23 December 2014 in English (English)

I had to take the bus to the city center and back yesterday. While searching for the correct boarding locations (3 different locations within a kmsq), I noticed quite a lot has changed. During the wait for the arrival of the return bus, I wished that my ver 1 galaxy tab has the processing power to run vespucci to do on the spot corrections. Vespucci used to run & edit, but nowadays it runs without showing maps & data from osm anymore, only a black screen. Need to start saving for upgrade I guess (or win a lucky draw somewhere).

BTW, any of you visiting my country are more than welcomed to help map that area. :) (our currency is devaluing right now, more bang for your money!)

Location: Chinatown, Starhill, Kuala Lumpur, Malaysia

No Waiting

Posted by kucai on 14 October 2014 in English (English)

I am getting tired fixing the automated notes. For every river crossing, some darned program will put a river name note. For every overpass, it will put no waiting on both sides of the bridge. Then there is the "Go ahead" notes popping up here and there.

Luckily, our main North South highway is only few hundred kilometers long. God help me if it is as long as I-40...

Location: North–South Expressway, Tanah Mas, Perak, Malaysia

Mapbox satellite view experiment

Posted by kucai on 14 August 2014 in English (English)

Been trying to get more zoom than just level 17 with iD and Potlatch. I tried using browser zoom view, which is quite usable for Chrome and Mozilla, but doesn't work with IE. It didn't work with Potlatch either, the satellite view remained constant regardless of browser zoom level.

Also, using iD on 19in monitor with max browser zoom, will leave about 2 inches of vertical editing area. To get best alignment, I left out the tagging process for later so that I get to trace with thin lines instead of the fat iD highway line types.

It was a slow process. I'll rather wait for better imagery (or JOSM implementation of iD zoom interpolation) for those areas, which we'll probably get in 3 years. Hopefully!

Location: Taman Temerloh Jaya, Taman Permai Indah, Temerloh, Pahang, 28000, Malaysia

Senarai lokasi masjid

Posted by kucai on 27 June 2014 in Malay (Bahasa Melayu)

Assalamualaikum.

Aku ada jumpa senarai masjid/surau untuk daerah hulu langat yang siap lengkap dengan gps koordinit (lari sikit dari lokasi sebenar, kadang2 kena search keliling baru jumpa kubah masjid), nama masjid, nama kampung dsbnya. Baru sempat siap dalam 20 lokasi gitu, maklum le bila download area sekitar point guna JOSM, kawasan keliling pun touchup sikit2. Guna shift-D, copy paste koordinit, zoom out sikit hingga skala kat atas kiri skrin tunjuk dalam 50meter, lepas tu klik download to current data layer.

Lepas tu aku call diorang, katanya kat JAIS ada senarai untuk seluruh Selangor. Haa... terbeliak mata nak siap, tapi insyaAllah pahala banyak wooo...

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