Google Earth Updates

[laohuaqiao]

Google Earth released the latest version a few weeks ago, 4.3 (beta)

Seems as if with each new update, Google is adding more regions in China with high resolution satellite images

Most of western part of Taishan can be viewed in high res, while eastern part of Taishan, including Taishan City, is still lower res. (22 15'50.02" N, 112 46'57.47" E )

For high res image in Google Earth, see for example Moy Family Complex ( 梅家大院 ) in Duanfen district (端芬 ), long-lat coordinates 22 02'38.17" N, 112 44'32.99" E.

The complex consists of 108 2-3-story buildings surrounding a rectangular courtyard, built by overseas Chinese about 100 years ago. If you zoom in the (GoogleEarth) image enough, you can make out the courtyard.



Anyway, what I'm trying to say is what I have just learned, we should update Google Earth whenever it is available.

[laohuaqiao]

Because maps of China usually are not detailed enough to show rural roads to villages, GPS devices are invaluable to trace the roads and exact locations of villages and points of interests. There have been some concerns with the overt use of GPS in China, whether the devices will work in China or whether Chinese government is jamming satellite signals.

It seems that there should no longer be any concern. At least one Chinese company is coming out /have come out with GPS units, shenxingzhe series, including maps and supporting Google Earth.

Have anyone used these devices? Any feedbacks would be helpful.

[Henry]

Hi Laohuaqiao,

I have used my cheap $89 USD Garmin eTREX GPS, from WalMart several times in China - works great. I suggest that you switch to the WGS 84 datum and that before you use it the first time in China - go outside where there are no obstructions and let the GPS unit sit for about 15 - 20 minutes. This allows the GPS unit to re-calibrate itself to the the particular GPS satellites orbiting around that location - ideally, you want exposure to the maximum number of satellites for the most accurate computation of lat/long coordinates - just make sure you take the time to identify your individual way points on the GPS unit. I got lazy and recorded them on paper instead with the waypoints on the unit and then got confused with locations. Several years ago, all survey grade GPS units had to be documented and registered before bringing and using them in China. While these units are not survey grade, I really do not want to try and explain the technical difference between this handheld unit, that can come within 25 feet of location accuracy, and a survey grade GPS unit to the arresting Chinese police officer or soldier. I use my unit without much fanfare and when asked what it is - I smile and say it is a cell phone.

By the way, it is great to have the geographic coordinates of the ancestral village, cemetery locations etc - these coordinates do not need any language translations - they are the street address on the ground.


Henry

[Woodson]

More and more handsets are equipped with GPS anyway. In a year or two's time each and every cellphone owner will have a GPS unit also.

[Henry]

Yes, both sides of general consumer applications of GPS technology - on one side: the Personal Navigational Devices (PND ) as in handheld GPS units & car navigation units and the other side: GPS enabled cell phones - are becoming as we geographers like to say "ubiquitous".

In July 2007, Tele Atlas, one of the two major companies in the world, providing high quality digital databases for car navigation, was bought for 2.8 billion USD by Tom Tom, a leading Personal Navigation Device (PND) company. The following statistics and projection provide an indication for the growing trend:

2006 17 million PND
2007 35 million PND
2010 83 million PND

In October 2007, Navteq, the other leading developer of digital databases for navigation, was bought for 8.1 billion USD by Nokia. Nokia had 36 % world market share mobile handsets in 2006 with 346 million phone / mobile devices and will probably increase that number with the additional location based services capabilities added to their handsets - supported by their ownership of Navteq.

In these location based services markets, the one who owns the digital database for navigation is usually the winner because they are so expensive to build - that all the application companies lease the data or pay royalties on usage.

Henry

[laohuaqiao]

Then I'm curious to know if the GPS units being sold in China are survey grade or not. Also, if the mapping softwares included with those units provide more details on rural roads than what's currently available on the internet, since presumably they are marketed to the increasing number of car owners.

[tyuti1668]

"Cheap" tracker +Free map ( 51ditu.com is better than ditu.google.com (mapabc) for rural roads) + GoogleEarth
solves basic need (ex. locate & mark a place) in China
For example:
My home village (map.gogle.com) in Zhongshan

51dituhttp://52ditu.googlepages.com/home_old.htm (地图工具->按经纬度查询: 22.46784,113.284369)
VS
bbs.keyhole.com/ubb/download.php?Number=1128640 keyed in ditu.google.com
-
pro gears:
These junkies suggested about different option in China

[Henry]

Hi Laohuaqiao,

Most hand-held GPS units have an accuracy level of probably around 35 to 75 feet, hence, these hand-held GPS units would not considered survey grade instruments by surveyors - which have an accuracy of a foot or less. But, if you let the GPS unit sit in a location for an hour and expose it to the maximum number of satellites, you could probably get an accuracy of about 25 feet with a hand-held GPS unit.

I do not know what digital map databases are currently being offered by manufacturers of GPS units in China. These GPS units can probably work from digital map databases downloaded from Google type companies and also digital map databases that are created and sold locally.

Also, I do not know whether these GPS enabled mobile phones can be used directly to report and store the coordinates for the location of the mobile phone or whether the mobile phone just has an embbed GPS chip in the phone or via the triangulaion of mobile phone location from surrounding cell phone towers - that allows it to be tracked and then you are offered various commercial services based upon your current location. Hopefully, it has a basic capability to let the authorities know where you are located in an emergency situation.

Henry

[laohuaqiao]

Thanks Henry for your responses.

There are still roads signs in the rural areas of Taishan. I've done some bicycling and walking around the countryside. Google Earth resolution is still not good enough in some regions to resolve the small roads. I usually get to my destination by keep asking for directions (Chinese are not used to outsiders, they know their way around but frequently not very good at giving directions ). It would be very helpful and I would consider getting a Chinese GPS unit if it provides enough detail of roads.

This is site for one manufacturer, though not enough info is given on the mapping software.

www.link-create.com.cn

The complete US street map info is available for free from the US Census Bureau. I just wonder what sources are available for China.

[Henry]

Hi Laohuaqiao,

In January 2007, the State Bureau of Surveying and Mapping (SBSM), the national mapping organization of China, completed the creation of the set of 1:50,000 topographic maps of China. Besides hard-copy paper maps, they will also have the digital map databases - but, because this scale is considered a military scale - they may or may not be available to the public.

Depending on the municipal /county planning organizations or private mapping and telephone companies in China, digital map databases for Taishan and/or the SiYi region may be available from these government sources or commercial companies. I will be the Co-Chair of a session at the International Society for Photogrammetry and Remote Sensing (ISPRS) Congress in Beijing early next month and I will be seeing some of the leading people in China regarding such maps and digital map databases - so, stay tuned and I will provide a report afterwards.


Henry

[kiwi]

During my travels into China at the end of last year/beginning of this year , I have used a GPS that communicates Bluetooth with a HP Pocket PC. Google Earth (or Map) satellite images for China appear to be just as accurate as Australia/NZ google satellite images . Note if you use ditu.google.com, these maps are slightly offset to that satellite images in maps.google.com. There is a free utility on the internet where you can stitched together tile from google maps - it also works with ditu.google.com.
Other Chinese internet map resources are:

map.mapbar.com/a_jiangmen_taishan_map/
map.mapbar.com/a_jiangmen_kaiping_map/
(or map.baidu.com/# )
map.sogou.com/index.html#city=%u5168%u56FD&c=12554933.593749271,2527101.5625,16 Taicheng
map.sogou.com/index.html#city=%u5168%u56FD&c=12543667.968749273,2538853.515625,16 Kaiping
api.51ditu.com/iframe/mapwindow.html?city=kaiping&zoom=1
api.51ditu.com/iframe/mapwindow.html?city=taishan&zoom=1

For a view of the log of waypoints on our the bus route to Taicheng copy following text and paste into Notepad, save the text file as a kml file (say taicheng.kml). Double click on the file and google earth will display the route.

<?xml version="1.0" encoding="UTF-8"?>
<kml xmlns="http://earth.google.com/kml/2.2">
<Placemark>
<name>Taishan bus route</name>
<Style>
<LineStyle>
<width>2</width>
</LineStyle>
<PolyStyle>
<color>7dff0000</color>
</PolyStyle>
</Style>
<LineString>
<tessellate>1</tessellate>
<coordinates>
112.8589517,22.5396583,0 112.8586933,22.53882,0 112.8573967,22.533815,0 112.8545167,22.5248183,0 112.8298117,22.5098717,0 112.8265467,22.5067533,0 112.8268133,22.50641,0 112.8269117,22.5062267,0 112.8307867,22.4982917,0 112.83095,22.4978583,0 112.83126,22.4972967,0 112.8319167,22.4956967,0 112.83201,22.4955633,0 112.8322167,22.4954367,0 112.83276,22.49462,0 112.8328283,22.4941767,0 112.8328717,22.4937867,0 112.832855,22.4933633,0 112.8326267,22.4914567,0 112.8326367,22.4906683,0 112.8326667,22.4899583,0 112.8327,22.4893617,0 112.8327183,22.4890567,0 112.832715,22.4889067,0 112.832685,22.48879,0 112.83263,22.48871,0 112.8324767,22.4883867,0 112.83247,22.4882433,0 112.8324717,22.4880183,0 112.832435,22.48793,0 112.8323417,22.4878467,0 112.8322267,22.4878217,0 112.7798917,22.4552417,0 112.7808117,22.45339,0 112.7808533,22.4528267,0 112.78079,22.4521467,0 112.78081,22.4520033,0 112.7810067,22.45046,0 112.7811233,22.4496267,0 112.7811767,22.4491317,0 112.78121,22.4483267,0 112.7812133,22.448195,0 112.7812267,22.4476033,0 112.7811617,22.44683,0 112.7811283,22.4463667,0 112.78105,22.446185,0 112.7787817,22.4421667,0 112.7717517,22.4293683,0 112.7717567,22.4292517,0 112.7718,22.4290183,0 112.7719417,22.4286167,0 112.773055,22.4263333,0 112.77312,22.4260333,0 112.7732817,22.4247183,0 112.77309,22.4234667,0 112.7726317,22.42118,0 112.77264,22.420665,0 112.7728,22.4197767,0 112.7729967,22.4192383,0 112.7751533,22.4150083,0 112.7839117,22.400285,0 112.7841583,22.3996017,0 112.7868617,22.3946383,0 112.799955,22.379805,0 112.7999633,22.3796433,0 112.7999733,22.3793367,0 112.79998,22.3791717,0 112.7999317,22.3790833,0 112.7999817,22.3789867,0 112.8000383,22.3789067,0 112.80073,22.3767883,0 112.8006583,22.37629,0 112.8006717,22.3761517,0 112.8006967,22.3751433,0 112.8004083,22.37385,0 112.7969283,22.3625267,0 112.7967683,22.3619183,0 112.793115,22.3425217,0 112.7931217,22.3419733,0 112.7931233,22.341515,0 112.7930783,22.3401883,0 112.7926383,22.3385083,0 112.7924417,22.3380367,0 112.7920183,22.336715,0 112.7919767,22.3363833,0 112.7919617,22.33619,0 112.791935,22.3359667,0 112.791905,22.33574,0 112.79127,22.331375,0 112.791195,22.33066,0 112.7911733,22.3304667,0 112.791165,22.3303767,0 112.79114,22.3302867,0 112.791095,22.3302167,0 112.7910733,22.330095,0 112.791045,22.3298483,0 112.7909683,22.3293383,0 112.790835,22.3289183,0 112.7906467,22.3284617,0 112.78998,22.32737,0 112.7870583,22.31973,0 112.7869283,22.3182767,0 112.7869033,22.3178167,0 112.7868883,22.3175667,0 112.7868733,22.31681,0 112.7868383,22.316495,0 112.7868333,22.316095,0 112.7867617,22.3148817,0 112.78658,22.3140283,0 112.7863567,22.3135217,0 112.7859583,22.3128883,0 112.781585,22.302645,0 112.7816083,22.3016767,0 112.7816467,22.3008133,0 112.782,22.2982467,0 112.7823383,22.2967617,0 112.782625,22.295731,0 112.7845983,22.2900133,0 112.7845567,22.2892217,0 112.78432,22.28813,0 112.7831233,22.2817283,0 112.7832683,22.2811567,0 112.7834783,22.28017,0 112.7833967,22.27899,0 112.783395,22.2742983,0 112.7835483,22.271625,0 112.7835683,22.2714133,0 112.7835633,22.27128,0 112.7835683,22.271115,0 112.7835817,22.27086,0 112.7835567,22.270525,0 112.7835267,22.270445,0 112.7835083,22.2703117,0 112.78344,22.270065,0 112.783245,22.2696067,0 112.782645,22.26864,0 112.7804267,22.265855,0 </coordinates>
</LineString>
</Placemark>
</kml>

[Henry]

Dear Colleagues,

When I attended the ISPRS Congress in Beijing during July 2008, I found out that the 1;50,000 digital maps of China have restricted access and foreigners cannot acquire them. It appears that only large organizations in China have access.

I have my own collection of 1;50,000 topographic map sheets of the SiYi region that are bi-lingual and compiled in the 1940s and are fantastic for genealogical purposes of locating ancestral villages, which may no longer appear on contemporary maps.


Henry