How much storage is required to store all of the images on Google Maps?

1. CLARIFY: 
   1. Do you mean Google Maps globally or for a specific region? You choose. 
   2. Should we include aspects of Google Maps like Google Satelite, Google Street View, etc.? You choose. 
2. BACKGROUND: Google Maps is a mapping service created by Google. It offers satellite imagery, aerial photography, street maps, 360° interactive panoramic views of streets, real-time traffic conditions, and route planning for traveling by foot, car, bicycle, air and public transportation. Google's mission is to organize the world's information and allow user's easy access to it, so Maps fits well with its mission. 
3. EQUATION: Total Google Maps image storage = Google Maps Satellite image storage + Google Street View Storage (360 degrees) + Static Image Storage + Icon / Drawing Storage
4. BREAKDOWN UNKNOWNS: 
   1. Google Maps Satellite:
      1. Surface Area of Earth: 
         1. Radius of Earth: ~ 4000 miles
         2. Surface Area of Earth: 
            1. 4Pi(r squared)
            2. 4 (3.14) (4000 squared) = ~201M square miles
      2. Storage for 1 Square Mile: Looking at Google Maps Satellite, assume that 1 square mile of sallite image is ~ 30 MB of storage. (Given that I can zoom in, etc. it's likely a little higher than a flat image.)
      3. Sallite Storage for All Earth: 
         1. Let's assume Sallite images do not cover all of Earth - say 70% coverage. 
         2. Total Storage = 30MB * 201 M square miles = ~6B MB
   2. Google Street View Storage: 
      1. Total Storage in .5 Miles: 
         1. Based on my use of Google Street View, I've noticed that the 360 image changes every .5 miles. 
         2. Let's assume that 1 image in .5 miles is 20MB or 40MB for 1 mile (2 images)
      2. Total Storage for in Street View: 
         1. Surface Area of Earth: ~ 201M square miles
         2. % Land: 
            1. Earth is ~ 30% land
            2. .3 (201M) = ~ 60M square miles of land
         3. Habitable Land: ~ 60% of land is dessert / mountains, which leaves ~40% that is habitable
            1. .4 (60M) = 24M habitable land
         4. Coverage by Google: 
            1. Let's assume Google covers 70% of the world's habitable land. 
            2. .7 * 24M = ~ 17M
         5. Image Storage Road Density: 
            1. I live in a big urban city with a high population. I will use that city as the example of my high density road and estimate other road density based on my city example. 
            2. In my city, when I walk one mile (~20 street blocks), I see a road every block - i.e. 20 roads. In 1 square mile, there's ~ 40 roads. Each road is 1 mile. 
            3. Given my rough knowledge of Earth, I'd assume most of habitable Earth is rural / low road density. The high road densities likely only occur in big cities. 

               1. Road Density	# of Roads / Square Mile	% of Habitable Land	Square Miles of Land	# of Roads Total	Image Storage
                  Low	10	50%	.5 (17M) = 8.5M	10 * 8.5M = 85M roads	85M * 40 MB = 3.4B MB
                  Medium	20	30%	.3 (17M) = 5.1M	20 * 5.1M = 102M roads	102M * 40 MB = 4.1B MB
                  High	40	20%	.2 (17M) = 3.4M	40 * 3.4M = 136M roads	136M * 40 MB = 5.4B MB

            4. Total MB of 360 Image Storage for Roads on Street View: 3.4B + 4.1B + 5.4B = 12.9B MB
   3. Google Static Images: 
      1. Total Number of Type of Environments:
         1. # of Cities: There are ~ 10K cities in the world.
         2. # of Towns: Let's assume based on my state, there are 5 towns / city: 10K * 5 = 50K towns.
         3. # of National Parks: 
            1. There are approximately 60 national parks in the US. Let's assume that the US has a high number. 
            2. There are 195 countries in the world. Let's assume the number of countries by # of park size. I assume countries with a high number of national parks is relatively small and most countries are smaller with fewer parks.

               1. Type of Country	# of Parks	# of Countries	Total Countries
                  Low	10	100	1000
                  Medium	30	65	1950
                  High	60	30	1800

            3. Total Number of National Parks: 1000 + 1950 + 1800 = 4750
      2. # of Landmarks / Environment Type:
         1. My city has on average 5 landmarks every 1 mile or 25 in 1 square mile. It's about 16 miles long and 9 miles wide = 144 square miles, which means there are 144 * 25 = 3600 land marks. 
         2. Let's use my city as the estimate for all cities in the world. (Understandably some may have less / more landmarks.).
         3. Let's also assume that a town has 10% of the landmarks as my city - given that everything is spread out.
         4. A national park will likely have even fewer landmarks. Let's estimate 100. 

         5. Type of Environment	# of Landmarks	Total Number of Environment	Total Landmarks
            City	3600	10K	36M
            Town	3600 * .1 = 360	50K	18M
            Park	100	4750	475K

         6. Total Landmarks: 36M + 18M + 475K = 54.5M
      3. Google Coverage of Landmarks: Like we stated with Google Satellite, let's assume Google has static images of 70% of the landmarks. 54.5M * .7 = ~38M landmarks
      4. Number of Images / Landmarks: 
         1. Let's assume that the average landmark has 5 images based on my experience with Google Maps. Some have high numbers 10+ and some have maybe just 1 image, so let's split the difference.
         2. 38M landmarks * 5 images / landmark = 190M images
      5. Total Storage of Static Images:
         1. Let's assume that each image is 5 MB.
         2. 190M * 5 MB = 950M MB
   4. Icon / Drawing Storage: 
      1. Storage for 1 Square Mile: 
         1. Habitable Land: Let's assume the storage for the iconography and digital drawings of Google map is 20MB for 1 square mile for habitable land. 
         2. Water / Non Habitable Land: 10 MB
      2. Total Storage for Earth: 
         1. Surface of Earth: 201M square miles
         2. Habitable Land: 17M square miles
         3. Water / Non Habitable Land: 201M - 17M = 184M square miles
         4. Although Google Maps may not map the ocean, etc, on Google Maps view, I still see blue images to cover the ocean, etc., so let's assume that Google Maps has images for 100% of the earth when it comes to the icons / digital drawings. 
         5. Total Storage: 17M * 20MB + 184M * 10 MB = 340M MB + 1,840M MB = 2.2B MB 
5. TOTAL STORAGE: ~6B MB (Satellite) + 12.9B MB (Street View 360) + 950M MB (flat image) + 2.2B MB (icons / drawings) = 22B MB

I can take a stab at this.

Are we talking about user submitted images of key spots to Google Maps which includes both flat and spherical images, icons? Will this also include all the images shot by 360′ street view, and user submitted photos (both flat and spherical)? I’ll assume, yes.

Calculating type of assets and file sizes –

1. Assets used –
a. Flat Photos – A 12 Megapixel photo is anywhere from 5-20 MB based on compression. We can go with 5MB assuming there are some compression algorithms.
b. Spherical Photos ( 360 ) – Google Maps now has street view 360 maps on many roads in N. America. But these are limited to roadways, key landmarks & national parks. Possibly around 15MB each
c. Icons, Text – average around 5KB

Calculating Google Maps coverage –

Google Maps has maps covering most of the world both urban & rural. So I would start by calculating the habitable area in the world.

We know that radius of earth is 6500 km’s. Surface area of earth would then be 4 x Pi x r (squared) ~ 500 Million sq. km’s. Earth is about 25% land, so land area is 125 Million sq. km’s. Assuming about 40% of this is habitable, we end up with 50 Million sq. km’s.

Now let’s assume Google has covered at least 70% of this habitable area = 35 M sq. km’s.

Calculating volume of assets –

1. Per 10 sq. km we can assume there are an average of at least 50 points of interest (gas stations, restaurants, parks, homes, etc.) which demand image assets.
2. Total number of national parks and landmarks in the world, let’s assume about 100,000 that have some sort of spherical media uploaded.
3. Assuming MAU’s on Google Maps is around 1 Billions users. Let’s assume about 10% upload at least 20 images to Maps. This gives us 2 Billion images uploaded
4. Per 10 sq. km we can assume there are an average of about 10 roads and 20 homes which demand icons or copy assets
a. Assuming 70% of roads have spherical media

With math above we arrive at these numbers on approximate number of assets stored in the cloud –
1. Points of Interest Images = 50 * 35 M sq. km/10 sq. km = 175 M images
2. 100,000 Landmarks with 100 spherical images each = 10 M spherical images
3. 2 Billion images uploaded by users
4. Roads & Homes
a. 70% * 35/10 * 10 = 25M spherical images
b. 35/10 * 20 = 7M images
5. Icons & Copy – assuming this as a total of all the above (points of interest + uploaded images + landmarks roads) = 2.875 B

Storage –
Flat images – 2.875 B * 5 MB = 14,375 TB
Spherical images – 35 M * 15 MB = 525 TB
Icons & Copy – 2.875B * 0.005 MB = 14.3 TB

Total storage = ~15K TB or 15 PB